U.S. patent application number 15/679168 was filed with the patent office on 2018-01-25 for laser-based devices utilizing multiple laser beams.
The applicant listed for this patent is VocalZoom Systems Ltd.. Invention is credited to Tal Bakish, Alexander Blumkin, Tal Fishman, Amir Ganani.
Application Number | 20180027339 15/679168 |
Document ID | / |
Family ID | 60990254 |
Filed Date | 2018-01-25 |
United States Patent
Application |
20180027339 |
Kind Code |
A1 |
Blumkin; Alexander ; et
al. |
January 25, 2018 |
Laser-Based Devices Utilizing Multiple Laser Beams
Abstract
A laser-based device or sensor includes: a first laser
transmitter having a first self-mix carrier frequency; a second
laser transmitter having a second, different, self-mix carrier
frequency; a first monitor photodiode to receive a first optical
signal from the first laser transmitter, and to output a first
electric signal; a second monitor photodiode to receive a first
optical signal from the second laser transmitter, and to output a
second electric signal; an electric connection to connect together
the first electric signal and the second electric signal, forming a
combined electric signal; a single laser receiver to receive the
combined electric signal and to generate from it a spectrum that
corresponds to both (i) self-mix signal of the first laser
transmitter, and (ii) self-mix signal of the second laser
transmitter. Alternatively, a single monitor photodiode is used,
receiving self-mix signals from multiple laser transmitters, and
outputting a single electric signal to a single laser receiver.
Inventors: |
Blumkin; Alexander;
(Nazareth Illit, IL) ; Ganani; Amir; (Zikhron
Ya'akov, IL) ; Fishman; Tal; (Haifa, IL) ;
Bakish; Tal; (Modi'in, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VocalZoom Systems Ltd. |
Yokneam Illit |
|
IL |
|
|
Family ID: |
60990254 |
Appl. No.: |
15/679168 |
Filed: |
August 17, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15017639 |
Feb 7, 2016 |
9755755 |
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15679168 |
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14997533 |
Jan 17, 2016 |
9756431 |
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15017639 |
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Current U.S.
Class: |
398/182 |
Current CPC
Class: |
H04B 10/503 20130101;
H04B 10/564 20130101; H04R 2410/00 20130101; H04B 10/506 20130101;
H04R 23/02 20130101; H04R 23/008 20130101 |
International
Class: |
H04R 23/00 20060101
H04R023/00; H04B 10/564 20060101 H04B010/564; H04B 10/50 20060101
H04B010/50 |
Claims
1. A device comprising: a first laser transmitter having a first
self-mix carrier frequency; a second laser transmitter having a
second, different, self-mix carrier frequency; a single monitor
photodiode (A) to receive a first optical signal from the first
laser transmitter, (B) to receive a second optical signal from the
second laser transmitter, (C) to output a single electric signal
that corresponds to both the first optical signal and the second
optical signal; a single laser receiver to receive the single
electric signal and to generate from it a spectrum that corresponds
to both (i) self-mix signal of the first laser transmitter, and
(ii) self-mix signal of the second laser transmitter.
2. The device of claim 1, comprising a plurality of laser
transmitters that are co-located and co-packaged, wherein all of
said laser transmitters are associated with said single monitor
photodiode that is external to and separate from all said laser
transmitters and is internal to said device.
3. The device of claim 1, further comprising: a first laser
modulator to modulate the first laser transmitter at a first
waveform, and to cause the first laser transmitter to transmit a
first laser beam having the first self-mix carrier; a second laser
modulator that is separate from the first laser modulator, wherein
the second laser modulator is to modulate the second laser
transmitter at a second waveform, and to cause the second laser
transmitter to transmit a second laser beam having the second
self-mix carrier.
4. The device of claim 1, wherein the first laser transmitter has a
first delta-wavelength to delta-current value, which indicates a
change in wavelength of a laser beam that is transmitted by the
first laser transmitter as a function of a change in current
supplied to said first laser transmitter; wherein the second laser
transmitter has a second delta-wavelength to delta-current value,
which indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is identical to the second delta-wavelength
to delta-current value of the second laser transmitter.
5. The device of claim 1, wherein the first laser transmitter has a
first delta-wavelength to delta-current value, which indicates a
change in wavelength of a laser beam that is transmitted by the
first laser transmitter as a function of a change in current
supplied to said first laser transmitter; wherein the second laser
transmitter has a second delta-wavelength to delta-current value,
which indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter.
6. The device of claim 1, wherein the first laser transmitter has a
first delta-wavelength to delta-current value, which indicates a
change in wavelength of a laser beam that is transmitted by the
first laser transmitter as a function of a change in current
supplied to said first laser transmitter; wherein the second laser
transmitter has a second delta-wavelength to delta-current value,
which indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.05 and
is not smaller than 0.95.
7. The device of claim 1, wherein the first laser transmitter has a
first delta-wavelength to delta-current value, which indicates a
change in wavelength of a laser beam that is transmitted by the
first laser transmitter as a function of a change in current
supplied to said first laser transmitter; wherein the second laser
transmitter has a second delta-wavelength to delta-current value,
which indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.10 and
is not smaller than 0.90.
8. The device of claim 1, wherein the first laser transmitter has a
first delta-wavelength to delta-current value, which indicates a
change in wavelength of a laser beam that is transmitted by the
first laser transmitter as a function of a change in current
supplied to said first laser transmitter; wherein the second laser
transmitter has a second delta-wavelength to delta-current value,
which indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.20 and
is not smaller than 0.80.
9. The device of claim 1, further comprising: a spectral analysis
module configured (A) to analyze a spectrum of signals received by
said single laser receiver, and (B) to identify in said spectrum a
first peak and a second peak that correspond, respectively, to the
first laser transmitter and the second laser transmitter, and (C)
to monitor a frequency shift of at least one of said first peak and
said second peak in response to movement of a remote target that is
hit by at least one of: a laser beam transmitted by the first laser
transmitter, and a laser beam transmitted by the second laser
transmitter, and (D) to determine one or more characteristics of
said remote target, based on said drift monitored in said
spectrum.
10. The device of claim 1, wherein the single monitor photodiode is
separate from both the first laser transmitter and the second laser
transmitter.
11. The device of claim 1, wherein the first and second laser
transmitters are co-packaged; and wherein the single monitor
photodiode is integrated within the co-packaged first and second
laser transmitters.
12. The device of claim 1, wherein the first and second laser
transmitters are monolithically integrated with each other; and
wherein the single monitor photodiode is also monolithically
integrated within the first and second laser transmitters.
13. The device of claim 1, wherein the first and second laser
transmitters are monolithically integrated with each other; and
wherein the single monitor photodiode is not monolithically
integrated within the first and second laser transmitters.
14. The device of claim 1, further comprising: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
utilizes a first electric circuitry to modulate the first laser
transmitter at a first waveform, and to cause the first laser
transmitter to transmit a first laser beam having the first
self-mix carrier; wherein said single laser modulator utilizes a
second electric circuitry to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
15. The device of claim 1, further comprising: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein, by utilizing a Distributed
Bragg Reflector (DBR) doping technique, said first and second laser
transmitters transmit respectively a first laser beam and a second
laser beam having two different self-mix carrier frequencies.
16. The device of claim 1, further comprising: a laser usefulness
estimator, to estimate self-mix signal usefulness of the first
laser transmitter, by comparing a quality indicator of the self-mix
signal usefulness of the first laser transmitter to one or more
pre-defined threshold values; a selective activation module (a) to
selectively de-activate the first laser transmitter and (b) to
maintain the second laser transmitter activated, if an estimated
self-mix usefulness value of the first laser transmitter is below a
particular pre-defined threshold value.
17. The device of claim 1, further comprising: a laser usefulness
estimator, to estimate self-mix signal usefulness of the first
laser transmitter, by comparing a Root Mean Square (RMS) amplitude
of the self-mix signal of the first laser transmitter to one or
more pre-defined threshold values; a selective activation module
(a) to selectively de-activate the first laser transmitter and (b)
to maintain the second laser transmitter activated, if an estimated
self-mix usefulness value of the first laser transmitter is below a
particular pre-defined threshold value.
18. The device of claim 1, further comprising: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter and
the second laser transmitter are located at a same distance from
said single lens assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part (CIP) of U.S.
patent application Ser. No. 15/017,639, filed on Feb. 7, 2016,
which is hereby incorporated by reference in its entirety; which is
a Continuation of U.S. patent application Ser. No. 14/997,533,
filed on Jan. 17, 2016, which his hereby incorporated by reference
in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of devices that
utilize laser beams.
BACKGROUND OF THE INVENTION
[0003] Millions of people worldwide utilize a variety of electronic
devices that may receive, capture or otherwise process audio
signals. For example, cellular phones and smartphones comprise an
audio microphone, allowing a user to conduct a telephone call with
a remote user. Similarly, a smartphone typically comprises an audio
microphone and a video camera, allowing the user to record an
audio/video clip. Additionally, many laptop computers as well as
tablets are typically equipped with an audio microphone able to
capture audio.
[0004] Unfortunately, an audio microphone typically captures a
desired audio signal (e.g., a voice of a human speaker) together
with background noise, interferences, ambient noises, environmental
noises, and/or audio from other non-desired sources.
SUMMARY OF THE INVENTION
[0005] Some embodiments of the present invention may comprise
systems, devices, and method for utilizing multiple lasers or
multiple laser beams or multiple laser transmitters, or a laser
array or laser matrix, in conjunction with a single laser drive
component and/or a single laser receiver component.
[0006] Some embodiments of the present invention may comprise an
optical microphone or laser microphone or a laser-based microphone,
or optical sensor or laser sensor or laser-based sensor, which
utilizes multiple lasers or multiple laser beams or multiple laser
transmitters, in conjunction with a single laser drive component
and/or a single laser receiver component, or in conjunction with a
single monitor photodiode (MPD) that is connected to a single laser
receiver, or in conjunction with multiple MPDs that are connected
to a single laser receiver; thereby increasing or improving
efficiency of self-mix techniques or module or chamber (or self-mix
interferometry techniques or module or chamber) utilized by such
optical or laser-based microphone or sensor, and thereby enabling a
possible reduction in manufacturing cost and/or enabling a reduced
form factor for the entire laser-based device or laser-based
microphone (e.g., due to utilization of a single laser receiver
instead of multiple, separate, laser receivers).
[0007] Some embodiments of the present invention may comprise a
hybrid sensor or hybrid device or hybrid unit or hybrid microphone,
for example, an acoustic/optical sensor or acoustic/optical
microphone, which may comprise: (a) an acoustic microphone or audio
microphone; and also (b) an optical microphone or laser microphone
or a laser-based microphone which utilizes multiple lasers or
multiple laser beams or multiple laser transmitters, in conjunction
with a single laser drive component and/or a single laser receiver
component. Optionally, optical feedback received by the laser
microphone, may be used in order to improve, enhance, filter and/or
clean noises from the acoustic signal captured by the acoustic
microphone.
[0008] The present invention may provide other and/or additional
advantages and/or benefits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A is a schematic illustration of a laser system, in
accordance with some demonstrative embodiments of the present
invention;
[0010] FIG. 1B is a schematic illustration of another laser system,
in accordance with some demonstrative embodiments of the present
invention;
[0011] FIG. 1C is a schematic illustration of still another laser
system, in accordance with some demonstrative embodiments of the
present invention;
[0012] FIG. 1D is a schematic illustration of another laser system,
in accordance with some demonstrative embodiments of the present
invention;
[0013] FIG. 1E is a schematic illustration of yet another laser
system, in accordance with some demonstrative embodiments of the
present invention;
[0014] FIG. 1F is a schematic illustration of still another laser
system, in accordance with some demonstrative embodiments of the
present invention;
[0015] FIG. 2A is a schematic illustration of a spectrum chart, in
accordance with some demonstrative embodiments of the present
invention;
[0016] FIG. 2B is a schematic illustration of another spectrum
chart, in accordance with some demonstrative embodiments of the
present invention;
[0017] FIG. 3A is a schematic illustration of a laser system, in
accordance with some demonstrative embodiments of the present
invention;
[0018] FIG. 3B is a schematic illustration of a laser system, in
accordance with some demonstrative embodiments of the present
invention;
[0019] FIGS. 4A-4E are schematic illustrations of laser systems, in
accordance with some demonstrative embodiments of the present
invention;
[0020] FIG. 5 is a schematic block-diagram illustration of a
device, in accordance with some demonstrative embodiments of the
present invention.
DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION
[0021] The Applicants have realized that it may be beneficial to
utilize an optical microphone or laser microphone or laser-based
microphone, by itself and/or as part of a hybrid system or hybrid
device that also comprises an acoustic microphone. The Applicants
have further realized that it may be beneficial to utilize an
optical microphone or laser microphone or laser-based microphone
that has multiple laser drives (or multiple laser drivers, or
multiple laser transmitters; or multiple laser emitters; or
multiple laser transceivers), in order to improve the efficiency
and/or the accuracy of such microphone, or of such hybrid device or
system. The Applicants have also realized that multiple laser
transmitters may be connected to a single Monitor Photodiode (MPD)
which may then feed a single laser receiver; or alternatively, that
multiple laser transmitters may be connected to multiple, separate,
MPDs which may then produce electric signals that may be shorted or
connected to each other prior to entering (or, at the entrance to)
a single laser receiver. The Applicants have realized that these
embodiments of the present invention may operate, for example, in
conjunction with two-or-more laser transmitters or emitters or
transceivers (or an array or a matrix or a set of such units), that
have different, respective, self-mix carrier frequency (or
frequencies).
[0022] It is clarified that the term "carrier frequency" is the
frequency of a carrier wave; and that the terms "self-mix" or
"self-mix signal" refer to a signal that is the result of
self-mixing of (i) an outgoing laser beam transmitted towards a
target, with (ii) an incoming (reflected) optical feedback signal
that is reflected back from said target. Accordingly, the term
"self-mix carrier frequency" means, the Carrier Frequency of the
Self-Mix Signal.
[0023] The Applicants have realized that self-mix (SM) techniques,
or a self-mix module or chamber, typically utilize a single laser
beam that is associated with a single laser drive (or laser driver)
and a single laser receiver. The Applicants have realized that it
may be beneficial to utilize multiple lasers or multiple laser
beams, in order to improve or enhance the efficiency of self-mix
techniques or modules or chambers. Furthermore, the Applicants have
realized that it may be beneficial to utilize multiple lasers or
multiple laser beams or multiple laser transmitters, in conjunction
with a single laser drive component and/or a single laser receiver
component; for example, since multiple laser emitters or
transceivers may share the same optics, thereby reducing the
foot-print and/or the form-factor and/or the size and/or the volume
and/or the cost of the device or the system.
[0024] Some embodiments of the present invention may comprise an
optical microphone or laser microphone or a laser-based microphone,
or optical sensor or laser sensor or laser-based sensor, which
utilizes multiple lasers or multiple laser beams or multiple laser
transmitters, in conjunction with a single laser drive component
and/or a single laser receiver component, thereby increasing or
improving the efficiency of self-mix techniques or module or
chamber (or self-mix interferometery techniques or module or
chamber) utilized by such optical or laser-based microphone or
sensor.
[0025] Some embodiments of the present invention may comprise, or
may be implemented as, for example: a monolithically integrated
laser and a sensor, or monolithically integrated lasers and
sensors, or a monolithically integrated lasers array (or matrix)
and a sensor.
[0026] Some embodiments of the present invention may comprise a
hybrid sensor or hybrid device or hybrid unit or hybrid microphone,
for example, an acoustic/optical sensor or acoustic/optical
microphone, which may comprise: (a) an acoustic microphone or audio
microphone; and also (b) an optical microphone or laser microphone
or a laser-based microphone which utilizes multiple lasers or
multiple laser beams or multiple laser transmitters, in conjunction
with a single laser drive component and/or a single laser receiver
component. Optionally, optical feedback received by the laser
microphone, may be used in order to improve, enhance, filter and/or
clean noises from the acoustic signal captured by the acoustic
microphone.
[0027] The terms "laser" or "laser transmitter" as used herein may
comprise or may be, for example, a stand-alone laser transmitter, a
laser transmitter unit, a laser generator, a component able to
generate and/or transmit a laser beam or a laser ray, a laser
drive, a laser driver, a laser transmitter associated with a
modulator, a combination of laser transmitter with modulator, a
combination of laser driver or laser drive with modulator, or other
suitable component able to generate a laser beam.
[0028] Some embodiments of the present invention may provide or may
comprise a laser-based device or apparatus or system, a laser-based
microphone or sensor, a laser microphone or sensor, an optical
microphone or sensor, a hybrid acoustic-optical sensor or
microphone, a combined acoustic-optical sensor or microphone,
and/or a system that comprises or utilizes one or more of the
above.
[0029] In some embodiments, multiple (two or more) laser
transmitters are connected to a single monitor photodiode (MPD);
which in turn outputs a single electric signal into a single laser
receiver, which may convert the electric signal to a spectrum.
[0030] In some embodiments, multiple (two or more) laser
transmitters are connected separately to multiple (two or more)
respective MPDs; which in turn output multiple electric signals,
that are then shorted together or connected together prior to
entering (or at the entrance of) a single laser receiver, which may
convert the electric signal to a spectrum. Optionally, a beam
splitter or other suitable element may be used in such
configuration. Alternatively, the MPDs may be monolithically
integrated within the lasers structure.
[0031] In accordance with the present invention, the first laser
transmitter has a first self-mix carrier frequency; and the second
laser transmitter has a second, different, self-mix carrier
frequency. Similarly, if K laser transmitters are used together
with a single laser receiver (e.g., through a single MPD, or
through multiple MPDs whose outputs are shorted together), them K
different self-mix carrier frequencies are used and characterized
the respective K laser transmitters; in order to enable the single
laser receiver to correctly service (or be associated with) the
multiple laser transmitters.
[0032] It is noted that the term "self-mix signal" of a laser may
refer, for example, to the signal that is induced by (or generated
by) self-mix of the outgoing laser beam (which is outgoing from the
laser) with the incoming or received or reflected feedback optical
signal (which is incoming into the laser after transmitted laser
beam has hit a target and was reflected back from such target).
[0033] In some embodiments, the multiple laser transmitters may
have multiple different self-mix carrier frequencies by using one
or more suitable methods or circuits; for example, by changing or
modifying or differently modulating the wavelength of each laser
transmitter, thereby affecting or modifying or distinguishing the
self-mix carrier frequency of each laser transmitter; by changing
the physical properties of each laser transmitter (e.g., the radius
or the diameter, or the dimensions, of the physical hardware
component that emits or generates the laser beam), by changing the
operational temperature of each laser transmitter (e.g., by
heating-up or cooling-down one or more of the laser transmitters,
thereby causing a change in the wavelength, thereby causing a
change in the self-mix carrier frequency), by changing or setting
differently the resistance of each laser transmitter, and/or by
other suitable methods or circuits.
[0034] In some embodiments, each one of the multiple laser
transmitters, is operationally associated with its own, separate,
modulator; which provides its laser transmitter with a unique,
different, modulation; thereby ensuring that each laser transmitter
has a different and unique self-mix carrier frequency, relative to
the other laser transmitters.
[0035] In some embodiments, the multiple laser transmitters are
operationally associated with a single modulator, which may still
be able to ensure that each laser transmitter has a different and
unique self-mix carrier frequency, relative to the other laser
transmitters; for example, by modulating each laser transmitter at
a different wavelength (e.g., by utilizing resistors and/or
electrical components and/or electric circuits); which in turn
causes each laser transmitter to generate a laser beam having a
different self-mix carrier frequency (relative to all the other
laser transmitters in the apparatus).
[0036] In some embodiments, optionally, a control unit may
selectively turn-off and turn-on (or, may selectively activate and
de-activate) each one of the laser transmitters, separately from
the other laser transmitter(s); and/or may modify, decrease and/or
increase the strength or the power of each laser transmitter
separately from other laser transmitter(s). For example, if a
particular laser transmitter, out of two or more laser transmitter,
does not "hit" the intended target, or does not produce a signal or
does not produce a useful signal, or produces a low-quality signal,
then the control unit may selectively deactivate such particular
laser transmitter, or may reduce its power-level or its strength;
for example, in order to conserve power or save power or reduce
power consumption (e.g., which may be important, especially if the
system or apparatus has a limited power, or is a portable or mobile
device or apparatus that has an internal battery or internal
power-source).
[0037] Reference is made to FIG. 1A, which is a schematic
illustration of a laser system 100 in accordance with some
demonstrative embodiments of the present invention.
[0038] In a first demonstrative embodiment of the present
invention, two or more laser transmitters may be co-located, in
proximity to each other. For demonstrative purposes, two separate,
discrete, laser transmitters are shown, denoted 101 and 102;
although more than two laser transmitters (namely, N laser
transmitters, wherein N is a positive integer) may be used.
[0039] The multiple laser transmitters 101-102 are co-located in
proximity to each other, and are packaged close to each other, and
are all associated with a single laser driver and modulator 103
which is common to all of the laser transmitters 101-102.
[0040] In accordance with the present invention, each laser
transmitter is connected to its own monitor photodiode (MPD); which
may optionally be internal to (or comprised in, or monolithically
integrated within) the laser transmitter, or alternatively may be
external to (or connected to, or associated with) the laser
transmitter.
[0041] For example, laser transmitter 101 is connected to its own
MPD 111; which may optionally be internal to (or comprised in, or
monolithically integrated within) laser transmitter 101, or
alternatively may be external to (or connected to, or associated
with) laser transmitter 101. Similarly, yet separately, laser
transmitter 102 is connected to its own MPD 112; which may
optionally be internal to (or comprised in, or monolithically
integrated within) laser transmitter 102, or alternatively may be
external to (or connected to, or associated with) laser transmitter
102.
[0042] All the MPDs 111-112 are shorted together, for example, at
the input of a single, common, laser receiver 115 (e.g., at node
142), or prior to (or, immediately prior to) the input of the
common laser receiver 115 (e.g., at node 141). Spectrum analyzer
module 135 may process or analyze a spectrum and/or other
characteristics of the signal(s) outputted by the laser receiver
115; for example, as described herein with reference to FIGS. 2A
and 2B. The spectrum analyzer module 135 (or other Spectral
Analysis unit or module) may be implemented using a Fast-Fourier
Transform (FFT) unit applied on the sampled data; the output of the
FFT unit represents or indicates the spectral distribution of the
input signal; for example, if the input signal is sinusoidal then
the FFT output will have a peak at the frequency of the sinusoidal
signal; a peak-searching or peak-seeking algorithm or unit may then
search for, and find or detect, such peak(s) and their respective
frequency or frequencies.
[0043] Optionally, a single lens 116 (or other optics, or other
optical component or element) may focus or direct or otherwise
affect all (or some of) the laser beams at the output, to be
parallel or generally-parallel to each other; or alternatively, to
be slightly slanted relative to each other; thereby creating
multiple spots 121-122 on a target area of a target object 120.
Each spot 121-122 may correspond to a "hit" by one of the multiple,
discrete, separate, laser beams that originated from the multiple,
discrete, separate, laser transmitters 101-102. Optionally, more
than one lens may be used; or an arrangement of multiple lenses or
multiple optics or multiple optical elements may be used.
[0044] The input current to the laser transmitters may be modulated
by the laser driver and modulator 103, to create a self-mix (SM)
carrier frequency (denoted f.sub.0). The SM carrier frequency
f.sub.0 may depend on various parameters, including for example, a
DWL (or dWL, or Delta of Wave Length or Difference of Wave Length)
parameter indicating the change in wavelength versus (or as a
function of) the change of input laser current (or, as a function
of the change of power that is provided to the laser; or as a
function of the change of power that is consumed by the laser), or
indicating the sensitivity of the laser wavelength to changes in
the input current of the laser, or indicating a
wavelength-to-current coefficient or relation parameter. In some
embodiments, optionally, the value of the DWL parameter may be set
or modified or configured, as a configuration parameter of the
particular laser implementation being used, or by replacing a first
type of laser having a first DWL parameter value with a second,
different, type of laser having a second, different, DWL parameter
value.
[0045] In some embodiments, the resulting self-mix carrier
frequency f.sub.0 is proportional to the current change rate
(dI/dt), and the proportion or relation is indicated via a
parameter which may be denoted as DWL or as dWL or as dWL/dI,
namely, the change in wavelength versus (or as a function of) the
change in laser current. Other parameters may affect the resulting
self-mix carrier frequency f.sub.0, such as, for example, the
target distance and/or the laser wavelength. The dWL parameter
indicates the change in wavelength versus (or as a function of) the
change of input laser current (or, as a function of the change of
power that is provided to the laser; or as a function of the change
of power that is consumed by the laser).
[0046] In accordance with the present invention, the dWL parameter
of each one of the lasers (or, of each one of the laser
transmitters), is pre-defined or is pre-configured within the laser
structure. In some embodiments, each laser transmitter has the same
dWL value as each other laser transmitter of the same device. In
other embodiments, each laser transmitter has a dWL value that is
not more than 1.1 times and is not less than 0.90 times the dWL
value of each other laser transmitter in the same device. In other
embodiments, each laser transmitter has a dWL value that is not
more than 1.05 times and is not less than 0.95 times the dWL value
of each other laser transmitter in the same device. In other
embodiments, each laser transmitter has a dWL value that is
different from, and is non-identical to, each other dWL value of
each other laser transmitter in the same device; such that no two
laser transmitters of the same device have the same dWL value.
[0047] For demonstrative purposes, and as non-limiting examples,
two or more of the lasers may be configured or structured to
utilize or to have one or more of the following dWL values:
dWL=0.30 nanometer/milliamper; dWL=0.35 nanometer/milliamper;
dWL=0.40 nanometer/milliamper. In one embodiment, two lasers may
have the following two, respective, dWL values: dWL1=0.30
nanometer/milliamper; dWL2=0.35 nanometer/milliamper. In another
embodiment, two lasers may have the following two, respective, dWL
values: dWL1=0.30 nanometer/milliamper; dWL2=0.40
nanometer/milliamper. In another embodiment, two lasers may have
the following two, respective, dWL values: dWL1=0.35
nanometer/milliamper; dWL2=0.40 nanometer/milliamper. In another
embodiment, three lasers may have the following three, respective,
dWL values: dWL1=0.30 nanometer/milliamper; dWL2=0.35
nanometer/milliamper; dWL2=0.40 nanometer/milliamper.
[0048] In some embodiments, each dWL value of each one of the
laser, may be different from each other dWL value of any other
laser of the same apparatus. In some embodiments, in addition to
such dWL diversity condition, or instead of such dWL diversity
condition, each dWL value of any one of the lasers of the
apparatus, is in the range of 0.10 to 0.75 nanometer/milliamper. In
some embodiments, in addition to such dWL diversity condition, or
instead of such dWL diversity condition, each dWL value of any one
of the lasers of the apparatus, is in the range of 0.20 to 0.60
nanometer/milliamper. In some embodiments, in addition to such dWL
diversity condition, or instead of such dWL diversity condition,
each dWL value of any one of the lasers of the apparatus, is in the
range of 0.25 to 0.50 nanometer/milliamper.
[0049] In some embodiments, the dWL value of a first laser of the
apparatus, is at least K percent smaller than the dWL value of a
second laser of the same apparatus; where K is pre-defined to be,
for example, 5 percent, or 10 percent, or 15 percent, or 20
percent, or 25 percent, or 30 percent, or 33 percent, or 35
percent, or 40 percent, or 50 percent, or 75 percent. Other
suitable values or ranges may be used, to achieve particular
implementation goals.
[0050] Each one of the laser transmitters 101-102 has a different
DWL value, and thus a different SM carrier frequency. Accordingly,
for example, laser transmitter 101 has a first DWL value (DWL1)
and/or has a first SM carrier frequency; whereas laser transmitter
102 has a second, different, DWL value (DWL2) and/or has a second,
different, SM carrier frequency.
[0051] In accordance with the present invention, each one of the
laser transmitters 101-102 has a different SM carrier frequency
f.sub.0 value; and the n-th SM carrier frequency may be denoted
f.sub.0n. In some embodiments, optionally, each laser transmitter
may comprise a separate laser driver, having a modulation amplitude
or frequency (or other functional form) independent from (and
different from) the amplitude or frequency (or other functional
form) of that other laser driver(s), and thus having a different,
unique, SM carrier frequency for each of the lasers.
[0052] In some embodiments, the DWL value of a particular laser
(or, of each particular laser) of the apparatus, may be set or
preset or changed or modified, for example, by setting or
presetting or modifying or changing the Direct Current (DC) that is
supplied to the laser, based on a pre-defined list or lookup table
of settings or values or sets-of-values or pairs-of-values. For
example, a first value of DC may correspond to a first DWL value
for that particular laser; a second (different) value of DC may
correspond to a second (different) DWL value for that laser; and so
forth. The values may be determined in advance in a lab, or may be
measured or determined by performing a series of changes of the DC
and measuring their effect on the respective DWL values. In some
embodiments, setting or modification of DC current that is supplied
to a laser, in order to set or modify the respective DWL value of
that laser, may be performed dynamically while the apparatus is
operational; for example, triggered by a detection that the
contribution of a particular laser to the general efficiency of the
apparatus (e.g., the quality of the self-mix signal) is below a
pre-defined threshold; and/or based on other suitable conditions or
detections. Such setting and/or modification of the DC supplied to
each laser, may be performed or controlled or regulated by a
suitable module or unit, for example, a laser DC controller, or a
laser DC modification unit, or a laser DC regulator, which may
perform one or more or all of the above-mentioned operations.
[0053] System 100 may optionally comprise a selective activation
module 151, able to selectively turn-on and turn-off (or,
selectively activate and de-activate) each one of the laser
transmitters 101 and 102; for example, as described further herein.
The selective activation module 151 may optionally comprise a power
regulator or a power regulation module, to perform power regulation
operations; for example, to selectively increase or decrease power
provided to a laser transmitter, in addition to (or instead of)
selectively activating/deactivating laser transmitter(s).
[0054] Reference is made to FIG. 1C, which is a schematic
illustration of a laser system 161 in accordance with some
demonstrative embodiments of the present invention. In laser system
161, instead of a single modulator, two separate "laser driver and
modulator" units 103A and 103B are used: for example, laser driver
and modulator 103A drives and modulates laser transmitter 101; and
modulator 103B drives and modulates laser transmitter 103B. The two
laser drivers and modulator units 103A and 103B ensure that each
one of the laser transmitters 103A and 103B has a different
self-mix carrier frequency; for example, by providing a different
modulation amplitude, frequency or functional form to each laser
transmitter, or by each one of the laser driver and modulator units
103A-103B utilizing a different modulating circuitry.
[0055] Reference is made to FIG. 1D, which is a schematic
illustration of a laser system 171 in accordance with some
demonstrative embodiments of the present invention. Laser system
171 is generally similar to laser system 100 of FIG. 1A; but in
laser system 171, a single MPD 191 is utilized in conjunction with
two (or more) laser transmitters 101-102 and in conjunction with a
single laser receiver 115.
[0056] Reference is made to FIG. 1E, which is a schematic
illustration of a laser system 172 in accordance with some
demonstrative embodiments of the present invention. Laser system
172 is generally similar to laser system 150 of FIG. 1B; but in
laser system 172, a single MPD 191 is utilized in conjunction with
two (or more) laser transmitters 101-102 and in conjunction with a
single laser receiver 115.
[0057] Reference is made to FIG. 1F, which is a schematic
illustration of a laser system 173 in accordance with some
demonstrative embodiments of the present invention. Laser system
173 is generally similar to laser system 161 of FIG. 1C; but in
laser system 173, a single MPD 191 is utilized in conjunction with
two (or more) laser transmitters 101-102 that are driven and
modulated by two separate "laser driver and modulator" units
103A-103B, and in conjunction with a single laser receiver 115.
[0058] It is noted that the systems of FIG. 1D, FIG. 1E and/or FIG.
1F, may further comprise and/or may utilize a beam splitter or
other suitable component(s); for example, as shown in FIG. 3B
and/or as described herein with reference to FIG. 3B.
[0059] Reference is made to FIG. 2A, which is a schematic
illustration of a spectrum chart 201 of the signal(s) received
and/or processed by a laser-based system (e.g., by utilizing the
single laser receiver 115, or, by two laser receivers), from a
static (non-vibrating, non-moving, speaking) target, in accordance
with some demonstrative embodiments of the present invention.
[0060] Reference is also made to FIG. 2B, which is a schematic
illustration of a spectrum chart 202 of the signal(s) received
and/or processed by a laser-based system (e.g., by utilizing the
single laser receiver 115, or, by two laser receivers), from a
non-static (vibrating, moving, speaking) target, in accordance with
some demonstrative embodiments of the present invention.
[0061] As demonstrated by spectrum chart 201, the Applicants have
observed the signal on the raising section of the triangle input
modulation with a static target. In the demonstrative resulting
spectrum of chart 201, of the received signal from a static target
(e.g., after removing the carrier signal or the modulation
envelope), two (or more) peaks 231 and 232 exist, corresponding to
each one of the two (or more) laser beams transmitted by the two
(or more) discrete laser transmitters 101-102.
[0062] As demonstrated by spectrum chart 202, once the target
vibrates (e.g., the target being a mouth-area or face-area or
head-area or neck-area of a human speaker, and the speaker speaks
or utters sound thereby causing his skin to vibrate or to fold or
to move or to be non-static), each one of peaks 231 and 232 may
independently shift or move or "drift" to upper or lower frequency,
according to the target velocity V.sub.t(t). For example, peak 231
may drift to become peak 241; and similarly, peak 232 may drift in
the same drift direction, to become peak 242. The shift or drift of
each peak may be monitored and measured, and may be transformed
into the measurement of V.sub.t(t). For example, the peak location
may be found by finding the local maxima of the digitally-computed
Fast Fourier Transform (FFT) spectrum. The target speed V.sub.t(t)
may be calculated from the peak frequency difference
.DELTA.f.sub.0(t), for example, by using the following equation, in
which .lamda. is the wavelength:
V.sub.t(t)=.DELTA.f.sub.0(t)*.lamda./2
[0063] It is noted that, as realized and observed by the
Applicants, when the two laser transmitters 101-102 are aimed or
are directed towards the same target (e.g., the same speaker or
face or mouth-area), then, the spectrum shifts or drifts in the
same direction, and the shifting or drifting of the peaks 231-232
does not cause any mixing or re-ordering or shuffling of the two
"drifted" peaks 241-242.
[0064] Reference is now made to FIG. 1B, which is a schematic
illustration of a laser system 150 in accordance with some other
demonstrative embodiments of the present invention. System 150 may
be generally similar to system 100 of FIG. 1A; however, in system
150 each one of the laser transmitters 101-102 has the same DWL
value (denoted DWL), instead of different DWL values for the
different laser transmitters 101-102 as in FIG. 1A. In system 150,
the spectral separation between the multiple lasers is obtained by
using resistors and/or circuitry to ensure that each one of laser
transmitters 101-102 has a different SM carrier frequency;
optionally by utilizing different hardware properties (e.g.,
hardware size, radius or diameter of laser transmitter) for each
one of the laser transmitters 101-102.
[0065] System 150 may optionally comprise a selective activation
module 151, able to selectively turn-on and turn-off (or,
selectively activate and de-activate) each one of the laser
transmitters 101 and 102. The selective activation and
de-activation may be based on a pre-defined scheme or a
dynamically-generated scheme, for example, based on the relative
usage of each laser, or based on the relative usefulness of the
feedback received from each laser; and/or in order to reduce power
consumption and/or increase Signal to Noise Ratio (SNR). It is
noted that the selective activation module 151 may similar be
present, and may similarly operate, in system 100 of FIG. 1A, or in
other systems described herein.
[0066] The selective activation module 151 may optionally comprise,
or may be associated with, a self-mix usefulness estimator able to
estimate or calculate or measure the usefulness or
relative-usefulness of the optical signal of each one of the laser
transmitter; and/or able to estimate a self-mix usefulness value or
score, associated with each laser transmitter. For example, the
selective activation module 151 may selectively activate or
deactivate a laser transmitter, or may selectively regulate or
selectively modify the power level provided to a laser transmitter,
based on the estimated self-mix usefulness value, or if the
estimated self-mix usefulness value is smaller than (or greater
than) a pre-defined threshold, or is smaller than (or greater than)
a pre-defined ratio relative to that of other laser transmitter(s)
in the same system.
[0067] The present invention comprises a device that utilizes
multiple laser beams (e.g., two laser beams, or five laser beams,
or other number of laser beams). When utilizing multiple laser
beams for the particular devices and methods of the present
invention, there is a cost/benefit from each such laser beam.
Therefore, the Laser Usefulness Estimator module operates to
estimate or to determine, whether or not the Nth laser beam, or
whether the Nth laser transmitter, indeed contribute to the overall
usefulness of the laser system; for example by checking whether the
Signal to Noise Ratio (SNR) is increased if the Nth laser beam is
transmitted or not, or by comparing the overall SNR value (e.g.,
with the Nth laser beam, and without the Nth laser beam) to a
pre-defined threshold value or to a pre-defined range of values;
and/or by further monitoring the Power Consumption of the system
when such Nth laser beam is used (e.g., and detecting that the Nth
laser beam causes an increase of only K percent in the overall SNR
of the system, whereas the Nth laser beam causes an increase of J
percent in the overall power consumption of the system, whereas K
and J are compared by the Estimator to pre-defined ranges or
threshold values). Accordingly, such Estimator unit may determine
the "usefulness" or the "efficiency" or the "marginal usefulness"
or the "marginal efficiency" of the Nth laser transmitter (or the
Nth laser beam), or the "usefulness" or the "efficiency" of the
self-mix signal that is produced when such Nth laser beam is indeed
employed; and based on such estimated "usefulness" or "efficiency",
the Nth laser transmitter may be selectively de-activated or may be
activated, or may be maintained active, or may be maintained
de-activated, or may selectively be configured to receive less
power or more power (e.g., relative to other laser transmitter(s)
in the same system).
[0068] Additionally or alternatively, the Laser Usefulness
Estimator module or unit may be implemented by utilizing a
multi-laser sensor (e.g., within a vehicle) to monitor the driver's
speech and to reduce the background noise interference; some of the
laser beams that are transmitted by the apparatus will not hit the
driver's face, but rather, may hit the driver's seat (e.g., the
support cushion behind the driver's head); in such case, the
distance of the target may be measured by such multi-laser sensors
or distance sensors, to provide or to calculate or to estimate the
laser usefulness or laser effectiveness data, since the driver's
face distance may be known or may be estimated or may be
pre-configured or pre-defined. Accordingly, based on the estimated
distance of the target being hit, lasers that are estimated to hit
further points ("long distance" lasers) may be selectively shut
down or de-activated or their readings may be discarded or ignored;
optionally, such de-activated lasers may be selectively and/or
periodically be re-activated or turned-on again, in order to update
their current usefulness estimation.
[0069] In some embodiments, for example, the apparatus may be a
vehicular apparatus that comprise three laser transmitters that are
directed generally towards the estimated location in which a
driver's head is typically present; multiple distance sensors or
distance estimators or distance detectors may operate to determine
that, for example, Laser 1 hits a target located 41 centimeters
away; that Laser 2 hits a target located 42 centimeters away; and
that Laser 3 hits a target located 50 centimeters away;
accordingly, the Laser Usefulness Estimator may determine or may
estimate the Laser 1 and Laser 2 are estimated to be hitting the
front side of the face of the driver, whereas Laser 3 is estimated
to be hitting the support cushion of the driver's seat (rather than
the driver's head); and accordingly, Laser 3 may be selectively
de-activated or shut-down or turned off (or, may receive reduced
power), or its readings may be discarded or ignored; and
periodically (e.g., every K seconds, wherein K is 10 or 20 or 30 or
60 or other suitable value) Laser 3 may optionally be re-activated
again for a short period of time (e.g., for 1 or 2 or 5 or 10
seconds) in order to re-estimate the usefulness of its
contribution.
[0070] In some embodiments, for example, the laser usefulness
estimator may estimate the self-mix signal usefulness of the first
laser transmitter, by comparing a quality indicator such as
self-mix RMS Amplitude (e.g., Root Mean Square amplitude, or Peak
to Peak amplitude or distance) amplitude of the first laser
transmitter to one or more pre-defined threshold values or ranges,
in order to determine whether the first laser is sufficiently
effective or not, and thus in order to possibly trigger
de-activation of the first laser.
[0071] In some embodiments, for example, the laser usefulness
estimator may estimate the self-mix signal usefulness of a
particular laser transmitter, by comparing a quality indicator such
as self-mix RMS Amplitude (e.g., Root Mean Square amplitude, or
Peak to Peak amplitude or distance) amplitude of a particular first
laser transmitter to a respective quality indicator of another
laser of the same apparatus (or, to all the quality indicators of
all the other lasers of the same apparatus), in order to determine
whether that particular laser is sufficiently effective or not
relative to other lasers of the same apparatus, and thus in order
to possibly trigger de-activation of that particular laser; for
example, by turning-off or by de-activating the particular laser,
out of N lasers of the apparatus, which has the lowest Quality
Indicator value relative to all other lasers of that apparatus.
[0072] In accordance with other embodiments of the present
invention, all the laser transmitters (for example, laser
transmitters 101 and 102 mentioned above) may optionally have a
single, common, MPD. In some embodiments, such single MPD may
optionally be built-in or embedded within a VCSEL (vertical-cavity
surface-emitting laser), for example, by utilizing an array of
multiple laser transmitters that are co-located on a same, single,
chip or Integrated Circuit (IC) or Application Specific IC (ASIC).
In other embodiments, a single, common, external MPD may be
associated with (or connected to) the multiple laser transmitter;
and the light may be coupled via, for example, a beam splitter.
Such configurations may be used in conjunction with (or, as
modifications of) system 100 of FIG. 1A; or, such configurations
may be used in conjunction with (or, as modifications of) system
150 of FIG. 1B.
[0073] Reference is made to FIG. 3A, which is a schematic
illustration of a laser system 301, in accordance with some
demonstrative embodiments of the present invention. System 300
demonstrates multiple laser diodes (e.g., laser transmitters
311-312) that are associated with, or connected to, a single
built-in MPD 313. Further shown are the laser beams which may pass
through an optional lens 315 or other optical element(s), on their
way to hit a target 317 from which they are reflected or
"bounced".
[0074] Reference is made to FIG. 3B, which is a schematic
illustration of a laser system 351, in accordance with some
demonstrative embodiments of the present invention. System 300
demonstrates multiple laser diodes (e.g., laser transmitters
361-362) that are associated with, or connected to, a single
external MPD 363 (e.g., which is external to the multiple laser
transmitters 361-362; but which may be internal to the entire
system 351, or to the entire laser-microphone or optical-microphone
that implements system 351). Further shown are the laser beams
which may pass through an optional lens 365 or other optical
element(s), on their way to hit a target 367 from which they are
reflected or "bounced"; however, the outgoing laser beams, prior to
hitting the target 367, may be split by a beam splitter 378 which
splits and reflects them back to the single external MPD 363.
[0075] The following discussion may be applicable to any of the
systems and/or components described above, and/or to any of the
drawing(s). For example, the self-mix carrier frequency, denoted
f.sub.0, may be set or configured, or may be affected by, one or
more of the following parameters and/or operations.
[0076] The laser power is modulated; for example, by adding a
time-changing current to the Direct Current (DC) drive current. For
example the laser drive current is modulated such that the laser
changes its wavelength linearly over time. The change in laser
wavelength due to change in laser current, may be referred to as
dWL/dI; and this parameter may be referred to herein as "DWL" or
"dWL".
[0077] In some embodiments, the change in laser wavelength due to
change in current is majorly or dominantly due to change(s) in the
heating of the laser transmitter or laser element, and/or due to
changes in the temperature of the laser transmitter or laser
element, and/or due to changes in the environmental temperature in
proximity to the laser transmitter or laser element, and/or due to
change in the laser maximum gain wavelength, and/or due to changes
in the effective laser cavity length, and/or due to changes in the
laser's mirror maximal-reflectivity wavelength. In some lasers that
may be used in conjunction with the present invention (for example,
VCSEL or vertical-cavity surface-emitting laser), the heating of
the laser transmitter or laser element may be a result from the
large serial resistance of the top DBR (Distributed Bragg
Reflector). This resistance (and therefore, the value of the DWL
parameter) is determined or configured by the laser size (e.g., the
physical size or the physical dimensions or diameter or radius of
the laser component), by the number of DBR layers; by the doping of
the DBR, and/or by other parameters or characteristics.
[0078] The change (e.g., linear change, or non-linear change) in
laser wavelength is transforming by the self-mixing phenomena to
laser power oscillating by a frequency denoted f.sub.0, which
depends on one or more parameters or characteristics, for example:
(a) target distance (e.g., the distance between the laser
transmitter and the target that the laser transmitter is aiming
towards, such as, the face of a human speaker); (b) the actual
wavelength of the laser; (c) the rate of wavelength change (which
depends on the DWL parameter, on modulation amplitude and
frequency).
[0079] In some embodiments of the present invention that utilize a
laser-based system having a single laser transmitter: the
modulating signal that is used is a symmetric triangle wave-form.
For such waveform, for a static target, only one oscillation
frequency is obtained for both rising and falling slopes of the
triangle. For example, for a target at a distance of d1
centimeters, at modulation amplitude of A1 uA (peak to peak), at
modulation frequency of fm1 kHz, at DWL parameter value of DWL1
nm/mA, the self-mix carrier frequency f.sub.0 is denoted as
f.sub.01 kHz. However, if the target moves, the self-mix carrier
frequency f.sub.0 splits into two frequencies, one for each slope
of the triangle waveform.
[0080] In some embodiments of the present invention that utilize a
laser-based system having two laser transmitters: for a target at a
distance of d1 centimeters, utilizing a single laser modulator for
both lasers, that provides modulation amplitude of A1 uA at
modulation frequency of fm1 kHz; the system would have: (a) a first
laser transmitter with DWL parameter value of DWL1 nm/mA, and (b) a
second laser transmitter with DWL parameter value of DWL2 nm/mA;
such that the value of DWL2 is different from the value of DWL1.
Accordingly, the value of the first carrier frequency is
approximately f.sub.01 kHz; whereas the value the second carrier
frequency is approximately f.sub.02 kHz. Then, if the target (that
is hit by the laser) moves, each of the carrier frequencies again
splits into two, similarly to the above.
[0081] In order to demonstrate the above discussion, reference is
made to the following drawings and systems: FIG. 4A, in which
system 401 demonstrates a single laser transmitter operable with a
static target, in accordance with some embodiments of the present
invention; FIG. 4B, in which system 402 demonstrates a single laser
transmitter operable with a static target, in accordance with some
embodiments of the present invention; FIG. 4C, in which system 403
demonstrates two laser transmitters associated with a single laser
modulator and operable with a static target, in accordance with
some embodiments of the present invention; FIG. 4D, in which system
404 demonstrates two laser transmitters associated with a single
laser modulator and operable with a moving target, in accordance
with some embodiments of the present invention; and FIG. 4E, in
which system 405 demonstrates a single laser transmitter and an
optical beam splitter, in accordance with some embodiments of the
present invention.
[0082] System 401 of FIG. 4A demonstrates, for example: a laser
drive 411 (or laser transmitter) aiming a laser beam through a lens
413 (or other optics assembly) towards a target 414 (e.g., a face
of a human speaker); a laser driver and modulator 418, generating a
modulation waveform 417; a single MPD 412, and a single laser
receiver 415 which results in a spectrum 416 corresponding to a
static target on the rise and fall of the FFT of the received
signal.
[0083] System 402 of FIG. 4B demonstrates, for example: a laser
drive 411 (or laser transmitter) aiming a laser beam through lens
413 (or other optics assembly) towards target 414 (e.g., a face of
a human speaker); laser driver and modulator 418, generating a
modulation waveform 417; a single MPD 412, and a single laser
receiver 415 which results in two split spectrums 416A (rise of the
FFT) and 416B (fall of the FFT) corresponding to a moving
target.
[0084] System 403 of FIG. 4C demonstrates, for example: two laser
drives 411A and 411B (or two laser transmitters) aiming two laser
beams through a lens 413 (or other optics assembly, or multiple
lenses, or two different lenses) towards target 414 (e.g., a face
of a human speaker); a single laser driver and modulator 418,
generating a modulation waveform 417; two MPDs 412A and 412B that
are shorted together prior to entry into a single laser receiver
415, which results in a spectrum 416C corresponding to a static
target on the rise and fall of the FFT of the received signal.
[0085] System 404 of FIG. 4D demonstrates, for example: two laser
drives 411C and 411D (or two laser transmitters) aiming two laser
beams through a lens 413 (or other optics assembly, or multiple
lenses, or two different lenses) towards target 414 (e.g., a face
of a human speaker); a laser Rx component 420 and a laser Tx
component 419; the resulting FFT spectrum 421 is split into two
spectrums denoted 421A (FFT rise) and 421B (FFT fall), and further
indicating the different dWL values in each branch. For example,
target 414 may be a generally-moving target, or a vibrating
target.
[0086] System 405 of FIG. 4E demonstrates a laser system 405 in
accordance with some demonstrative embodiments of the present
invention. For example, a single laser transmitter 411 with a
single MPD 412 are used, with a single laser driver and modulator
418 and a single laser receiver 415; and a designated optical
device (such as an optical beam splitter 425, a lens array, and/or
a diffractive optical element) is utilized to split the laser beam
into multiple beams that hit the target at several locations or
spots, and each spot may be associated with different SM frequency
which can be analyzed separately (e.g., as in FIG. 4D), as shown in
spectrum 416E.
[0087] The systems of the present invention may provide one or more
advantages, for example: (a) Spackle noise reduction or elimination
or immunity; enabling to "hop" between spectral peaks in case one
of them is lower due to dark spackle occurrence; (b) Target
tracking, optionally replacing a MEMS mirror; such that utilization
of multiple laser transmitters may allow a laser-based device or
microphone or sensor to cover larger location(s) or multiple
location(s) of a target or a speaker; (c) Increase of the working
distance; for example, placing or positioning the various laser
transmitters on different separation (or at different distances)
from the lens, thereby creating images (or "hitting" the target) at
different distances; and for each target distance, a different
spectral peak is created and used; (d) Decreasing sensitivity to
lens focus, and eliminating the need for active alignment, by
placing or positioning the various laser transmitters on different
separation (or at different distances) from the lens. Other
advantageous may be achieved.
[0088] Reference is made to FIG. 5, which is a schematic
block-diagram illustration of a device 500, in accordance with some
demonstrative embodiments of the present invention. Device 500 may
comprise: a laser-based sensor/microphone 501, which may comprise a
laser system similar to system 100 or system 150 described above
(or to other systems or sub-systems described above). Device 500
may optionally comprise also: an acoustic microphone 502 able to
capture acoustic signals; and a processor 503 able to process
acoustic signals captured by the acoustic microphone 502 and/or
optical feedback received by the laser-based sensor/microphone
401.
[0089] Device 500 may be, or may comprise, or may be comprised in,
for example: a smartphone, a cellular phone, a cordless phone, a
tele-conference device or system, a video-conference device or
system; an audio/video sensor; a computer, a laptop computer, a
notebook computer, a desktop computer, a tablet, a gaming device, a
gaming console, a navigation device, a mapping device, a
route-guidance device; a vehicle, a motor vehicle, a vehicular
dashboard, a vehicular component; and/or other suitable device or
system.
[0090] The term "acoustic microphone" as used herein, may comprise
one or more acoustic microphone(s) and/or acoustic sensor(s); or a
matrix or array or set or group or batch or arrangement of multiple
such acoustic microphones and/or acoustic sensors; or one or more
sensors or devices or units or transducers or converters (e.g., an
acoustic-to-electric transducer or converter) able to convert sound
into an electrical signal; a microphone or transducer that utilizes
electromagnetic induction (e.g., a dynamic microphone) and/or
capacitance change (e.g., a condenser microphone) and/or
piezoelectricity (e.g., a piezoelectric microphones) in order to
produce an electrical signal from air pressure variations; a
microphone that may optionally be connected to, or may be
associated with or may comprise also, a pre-amplifier or an
amplifier; a carbon microphone; a carbon button microphone; a
button microphone; a ribbon microphone; an electret condenser
microphone; a capacitor microphone; a magneto-dynamic microphone; a
dynamic microphone; an electrostatic microphone; a Radio Frequency
(RF) condenser microphone; a crystal microphone; a piezo microphone
or piezoelectric microphone; and/or other suitable types of audio
microphones, acoustic microphones and/or sound-capturing
microphones.
[0091] The term "laser microphone" as used herein, may comprise,
for example: one or more laser microphone(s) or sensor(s); one or
more laser-based microphone(s) or sensor(s); one or more optical
microphone(s) or sensor(s); one or more microphone(s) or sensor(s)
that utilize coherent electromagnetic waves; one or more optical
sensor(s) or laser-based sensor(s) that utilize vibrometry, or that
comprise or utilize a vibrometer; one or more optical sensor(s)
and/or laser-based sensor(s) that comprise a self-mix module, or
that utilize self-mixing interferometry measurement technique (or
feedback interferometry, or induced-modulation interferometry, or
backscatter modulation interferometry), in which a laser beam is
reflected from an object, back into the laser, and the reflected
light interferes with the light generated inside the laser, and
this causes changes in the optical and/or electrical properties of
the laser, and information about the target object and the laser
itself may be obtained by analyzing these changes.
[0092] The terms "vibrating" or "vibrations" or "vibrate" or
similar terms, as used herein, refer and include also any other
suitable type of motion, and may not necessarily require vibration
or resonance per se; and may include, for example, any suitable
type of motion, movement, shifting, drifting, slanting, horizontal
movement, vertical movement, diagonal movement, one-dimensional
movement, two-dimensional movement, three-dimensional movement, or
the like. In some embodiments, measuring or detecting or estimating
"vibrations" of a target may include, for example, measuring or
detecting or estimating a speed (or velocity) of movement of the
target, or of the speed in which the skin of the target moves or
vibrates, or other characteristics that characterize the movement
or displacement or folding or skin or face-skin or body-skin when
(or due to) speech uttered by a human speaker.
[0093] In some embodiments of the present invention, which may
optionally utilize a laser microphone, only "safe" laser beams or
sources may be used; for example, laser beam(s) or source(s) that
are known to be non-damaging to human body and/or to human eyes, or
laser beam(s) or source(s) that are known to be non-damaging even
if accidently hitting human eyes for a short period of time. Some
embodiments may utilize, for example, Eye-Safe laser, infra-red
laser, infra-red optical signal(s), low-strength laser, and/or
other suitable type(s) of optical signals, optical beam(s), laser
beam(s), infra-red beam(s), or the like. It would be appreciated by
persons of ordinary skill in the art, that one or more suitable
types of laser beam(s) or laser source(s) may be selected and
utilized, in order to safely and efficiently implement the system
and method of the present invention.
[0094] In some embodiments which may optionally utilize a laser
microphone or optical microphone, such optical microphone (or
optical sensor) and/or its components may be implemented as (or may
comprise) a Self-Mix module; for example, utilizing a self-mixing
interferometry measurement technique (or feedback interferometry,
or induced-modulation interferometry, or backscatter modulation
interferometry), in which a laser beam is reflected from an object,
back into the laser. The reflected light interferes with the light
generated inside the laser, and this causes changes in the optical
and/or electrical properties of the laser. Information about the
target object and the laser itself may be obtained by analyzing
these changes.
[0095] The present invention may be utilized in, or with, or in
conjunction with, a variety of devices or systems that may benefit
from noise reduction and/or speech enhancement; for example, a
smartphone, a cellular phone, a cordless phone, a video conference
system or device, a tele-conference system or device, an
audio/video camera, a web-camera or web-cam, a landline telephony
system, a cellular telephone system, a voice-messaging system, a
Voice-over-IP system or network or device, a vehicle, a vehicular
dashboard, a vehicular audio system or microphone, a navigation
device or system, a vehicular navigation device or system, a
mapping or route-guidance device or system, a vehicular
route-guidance or device or system, a dictation system or device,
Speech Recognition (SR) device or module or system, Automatic
Speech Recognition (ASR) module or device or system, a
speech-to-text converter or conversion system or device, a laptop
computer, a desktop computer, a notebook computer, a tablet, a
phone-tablet or "phablet" device, a gaming device, a gaming
console, a wearable device, a smart-watch, a Virtual Reality (VR)
device or helmet or glasses or headgear, an Augmented Reality (AR)
device or helmet or glasses or headgear, a device or system or
module that utilizes speech-based commands or audio commands, a
device or system that captures and/or records and/or processes
and/or analyzes audio signals and/or speech and/or acoustic
signals, and/or other suitable systems and devices.
[0096] In some embodiments of the present invention, which may
optionally utilize a laser microphone or optical microphone, the
laser beam or optical beam may be directed to an estimated
general-location of the speaker; or to a pre-defined target area or
target region in which a speaker may be located, or in which a
speaker is estimated to be located. For example, the laser source
may be placed inside a vehicle, and may be targeting the general
location at which a head of the driver is typically located. In
other embodiments, a system may optionally comprise one or more
modules that may, for example, locate or find or detect or track, a
face or a mouth or a head of a person (or of a speaker), for
example, based on image recognition, based on video analysis or
image analysis, based on a pre-defined item or object (e.g., the
speaker may wear a particular item, such as a hat or a collar
having a particular shape and/or color and/or characteristics), or
the like. In some embodiments, the laser source(s) may be static or
fixed, and may fixedly point towards a general-location or towards
an estimated-location of a speaker. In other embodiments, the laser
source(s) may be non-fixed, or may be able to automatically move
and/or change their orientation, for example, to track or to aim
towards a general-location or an estimated-location or a
precise-location of a speaker. In some embodiments, multiple laser
source(s) may be used in parallel, and they may be fixed and/or
moving.
[0097] In some demonstrative embodiments of the present invention,
which may optionally utilize a laser microphone or optical
microphone, the system and method may efficiently operate at least
during time period(s) in which the laser beam(s) or the optical
signal(s) actually hit (or reach, or touch) the face or the mouth
or the mouth-region of a speaker. In some embodiments, the system
and/or method need not necessarily provide continuous speech
enhancement or continuous noise reduction; but rather, in some
embodiments the speech enhancement and/or noise reduction may be
achieved in those time-periods in which the laser beam(s) actually
hit the face of the speaker. In other embodiments, continuous or
substantially-continuous noise reduction and/or speech enhancement
may be achieved; for example, in a vehicular system in which the
laser beam is directed towards the location of the head or the face
of the driver.
[0098] Although portions of the discussion herein relate, for
demonstrative purposes, to wired links and/or wired communications,
some embodiments are not limited in this regard, and may include
one or more wired or wireless links, may utilize one or more
components of wireless communication, may utilize one or more
methods or protocols of wireless communication, or the like. Some
embodiments may utilize wired communication and/or wireless
communication.
[0099] The system(s) of the present invention may optionally
comprise, or may be implemented by utilizing suitable hardware
components and/or software components; for example, processors,
processor cores, Central Processing Units (CPUs), Digital Signal
Processors (DSPs), circuits, Integrated Circuits (ICs),
controllers, memory units, registers, accumulators, storage units,
input units (e.g., touch-screen, keyboard, keypad, stylus, mouse,
touchpad, joystick, trackball, microphones), output units (e.g.,
screen, touch-screen, monitor, display unit, audio speakers),
acoustic microphone(s) and/or sensor(s), optical microphone(s)
and/or sensor(s), laser or laser-based microphone(s) and/or
sensor(s), wired or wireless modems or transceivers or transmitters
or receivers, GPS receiver or GPS element or other location-based
or location-determining unit or system, network elements (e.g.,
routers, switches, hubs, antennas), and/or other suitable
components and/or modules. The system(s) of the present invention
may optionally be implemented by utilizing co-located components,
remote components or modules, "cloud computing" servers or devices
or storage, client/server architecture, peer-to-peer architecture,
distributed architecture, and/or other suitable architectures or
system topologies or network topologies.
[0100] In accordance with embodiments of the present invention,
calculations, operations and/or determinations may be performed
locally within a single device, or may be performed by or across
multiple devices, or may be performed partially locally and
partially remotely (e.g., at a remote server) by optionally
utilizing a communication channel to exchange raw data and/or
processed data and/or processing results.
[0101] In some embodiments of the present invention, an apparatus
or device of system comprises: a first laser transmitter having a
first self-mix carrier frequency; a second laser transmitter having
a second, different, self-mix carrier frequency; a first monitor
photodiode to receive a first optical signal from the first laser
transmitter, and to output a first electric signal; a second
monitor photodiode to receive a first optical signal from the
second laser transmitter, and to output a second electric signal;
an electric connection to connect together the first electric
signal and the second electric signal, forming a combined electric
signal; a single laser receiver to receive the combined electric
signal and to generate from it a spectrum that corresponds to both
(i) optical feedback of the first laser transmitter, and (ii)
optical feedback of the second laser transmitter.
[0102] In some embodiments, the first monitor photodiode is
separate from the second monitor photodiode; and wherein the first
and second monitor photodiodes, and the first and second laser
transmitters, and the single laser receiver, are co-located within
a same packaging.
[0103] In some embodiments, said electric connection, that connects
together the first and second electric signal, is an electric
connection located externally to the single laser receiver and
prior to an entry node of the single laser receiver.
[0104] In some embodiments, the first monitor photodiode and the
second monitor photodiode are shorted together at a node located
between (I) the first and second monitor photodiodes, and (II) an
input of said single laser receiver.
[0105] In some embodiments, said electric connection, that connects
together the first and second electric signal, is an electric
connection located internally within said single laser
receiver.
[0106] In some embodiments, said electric connection, that connects
together the first and second electric signal, is an electric
connection located at an entry node of said single laser
receiver.
[0107] In some embodiments, the apparatus comprises: a first laser
modulator to modulate the first laser transmitter at a first
waveform, and to cause the first laser transmitter to transmit a
first laser beam having the first self-mix carrier; a second,
separate, laser modulator to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0108] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
utilizes a first electric circuitry to modulate the first laser
transmitter at a first waveform, and to cause the first laser
transmitter to transmit a first laser beam having the first
self-mix carrier; wherein said single, laser modulator utilizes a
second electric circuitry to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0109] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein the first laser transmitter
has physical diameter of a first value; wherein the second laser
transmitter has physical diameter of a second, greater, value;
wherein, based on the different physical diameters of the first and
second laser transmitters, said first and second laser transmitters
transmit respectively a first laser beam and a second laser beam
having two different self-mix carrier frequencies.
[0110] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein the first laser transmitter
operates at a first temperature; wherein the second laser
transmitter operates at a second, greater, temperature; wherein,
based on different operational temperatures of the first and second
laser transmitters, said first and second laser transmitters
transmit respectively a first laser beam and a second laser beam
having two different self-mix carrier frequencies.
[0111] In some embodiments, the apparatus comprises: a selective
activation module to selectively activate and de-activate at least
one of the first laser transmitter and the second laser
transmitter.
[0112] In some embodiments, the apparatus comprises: a selective
activation module to selectively de-activate one laser transmitter
out of the first laser transmitter and the second laser
transmitter, based on self-mix usefulness of optical feedback
received by each one of said first and second laser
transmitters.
[0113] In some embodiments, the apparatus comprises: a laser
usefulness estimator to estimate self-mix usefulness of optical
feedback received by the first laser transmitter; a selective
activation module (a) to selectively de-activate the first laser
transmitter and (b) to maintain the second laser transmitter
activated, if an estimated self-mix usefulness value of the first
laser transmitter is below a pre-defined threshold value.
[0114] In some embodiments, the apparatus comprises: a laser
usefulness estimator (i) to estimate self-mix usefulness of optical
feedback received by the first laser transmitter, and (ii) to
estimate self-mix usefulness of optical feedback received by the
second laser transmitter; a selective activation module (a) to
selectively de-activate the first laser transmitter and (b) to
maintain the second laser transmitter activated, if an estimated
self-mix usefulness value of the first laser transmitter is smaller
by at least a pre-defined ratio from an estimated self-mix
usefulness value of the second laser transmitter.
[0115] In some embodiments, the apparatus comprises: a laser
usefulness estimator to estimate self-mix usefulness of optical
feedback received by the first laser transmitter; a selective
activation module (a) to selectively reduce a level of power
provided to the first laser transmitter, while maintaining the
first laser transmitter activated, and (b) to maintain a level of
power provided to the second laser transmitter, if an estimated
self-mix usefulness value of the first laser transmitter is below a
pre-defined threshold value.
[0116] In some embodiments, the apparatus comprises: a laser
usefulness estimator (i) to estimate self-mix usefulness of optical
feedback received by the first laser transmitter, and (ii) to
estimate self-mix usefulness of optical feedback received by the
second laser transmitter; a selective activation module (a) to
selectively reduce a level of power provided to the first laser
transmitter, while maintaining the first laser transmitter
activated, and (b) to maintain a level of power provided to the
second laser transmitter, if an estimated self-mix usefulness value
of the first laser transmitter is smaller by at least a pre-defined
ratio from an estimated self-mix usefulness value of the second
laser transmitter.
[0117] In some embodiments, the apparatus comprises: a selective
activation module to selective de-activate one laser transmitter
out of the first laser transmitter and the second laser
transmitter, and to reduce power consumption of the apparatus,
based on usefulness of optical feedback of the first laser
transmitter relative to usefulness of optical feedback of the
second laser transmitter.
[0118] In some embodiments, the apparatus comprises: a selective
activation module to selective de-activate one laser transmitter
out of the first laser transmitter and the second laser
transmitter, and to increase a Signal to Noise Ratio (SNR) of the
apparatus, based on usefulness of optical feedback of the first
laser transmitter relative to usefulness of optical feedback of the
second laser transmitter.
[0119] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter.
[0120] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter and
the second laser transmitter are located at a same distance from
said single lens assembly.
[0121] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter is
located at a first distance from said single lens assembly; wherein
the first laser transmitter is located at a second, different,
distance from said single lens assembly.
[0122] In some embodiments, the apparatus comprises: a spectral
analysis module configured (A) to analyze a spectrum of signals
received by said single laser receiver, and (B) to identify in said
spectrum a first peak and a second peak that correspond,
respectively, to the first laser transmitter and the second laser
transmitter.
[0123] In some embodiments, the apparatus comprises: a spectral
analysis module configured (A) to analyze a spectrum of signals
received by said single laser receiver, and (B) to identify in said
spectrum a first peak and a second peak that correspond,
respectively, to the first laser transmitter and the second laser
transmitter, and (C) to monitor a drift of at least one of said
first peak and said second peak in response to vibration of a
remote speaker that is hit by at least one: a laser beam
transmitted by the first laser transmitter, and a laser beam
transmitted by the second laser transmitter.
[0124] In some embodiments, the spectral analysis module is to
determine one or more characteristics of vibrations of said remote
speaker, based on said drift monitored in said spectrum.
[0125] In some embodiments, the apparatus comprises a laser-based
microphone.
[0126] In some embodiments, the apparatus comprises a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said apparatus is not in physical contact with
human speaker.
[0127] In some embodiments, the apparatus comprises a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said apparatus is not in physical contact with
human speaker; wherein the apparatus is embedded within a vehicular
component of a vehicle in which said human speaker is located.
[0128] In some embodiments, the apparatus comprises a hybrid
acoustic-and-optical sensor which includes at least: a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said apparatus is not in physical contact with
human speaker; an acoustic microphone able to capture acoustic
signals generated by said human speaker.
[0129] In some embodiments, the apparatus comprises a hybrid
acoustic-and-optical sensor which includes at least: a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said apparatus is not in physical contact with
human speaker; and an acoustic microphone able to capture acoustic
signals generated by said human speaker; wherein the apparatus
further comprises a processor to enhance the acoustic signals, that
are captured by said acoustic microphone, based on vibrations of
the facial-area of the human speaker that are sensed remotely by
the laser-based microphone.
[0130] In some embodiments, the apparatus comprises: a third laser
transmitter having a third self-mix carrier frequency, wherein the
third self-mix carrier frequency is different from the first
self-mix carrier frequency, wherein the third self-mix carrier
frequency is different from the second self-mix carrier frequency;
a third monitor photodiode to receive a third optical signal from
the third laser transmitter, and to output a third electric signal;
wherein said electric connection is to connect together the first
electric signal and the second electric signal and the third
electric signal; wherein said single laser receiver is to receive
an electric signal which is a combination of the first and the
second and the third electric signals, and to generate from said
electric signal a spectrum that corresponds to (i) optical feedback
of the first laser transmitter, and (ii) optical feedback of the
second laser transmitter, and (iii) optical feedback of the third
laser transmitter.
[0131] In some embodiments, the apparatus comprises: a plurality of
laser transmitters that are co-located and co-packaged, and are
associated with a respective plurality of separate monitor
photodiodes; wherein each one of the laser transmitters has a
self-mix carrier frequency that is different from any other
self-mix carrier frequency of any other laser transmitter of the
apparatus; wherein each one of the laser transmitters provides an
optical signal to each one of the respective separate monitor
photodiodes; wherein outputs of said plurality of monitor
photodiodes, are connected together prior to an entry node of said
single receiver.
[0132] In some embodiments, the electric connection that connects
together the first electric signal and the second electric signal,
and forms the combined electric signal, is an electric connection
located after the entry node of said single laser receiver, and
wherein each of the first and second electric signals is
pre-amplified before reaching said electric connection.
[0133] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein, by utilizing a Distributed
Bragg Reflector (DBR) doping technique, said first and second laser
transmitters transmit respectively a first laser beam and a second
laser beam having two different self-mix carrier frequencies.
[0134] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein the first laser transmitter
has a first value of wavelength-to-input-current sensitivity (dWL);
wherein the second laser transmitter has a second, different, value
of wavelength-to-input-current sensitivity (dWL); wherein, based on
the different first value and second value of
wavelength-to-input-current sensitivity (dWL), said first and
second laser transmitters transmit respectively a first laser beam
and a second laser beam having two different self-mix carrier
frequencies.
[0135] In accordance with some embodiments of the present
invention, a system comprises: a first laser transmitter having a
first self-mix carrier frequency; a second laser transmitter having
a second, different, self-mix carrier frequency; a single monitor
photodiode (A) to receive a first optical signal from the first
laser transmitter, (B) to receive a second optical signal from the
second laser transmitter, (C) to output a single electric signal
that corresponds to both the first optical signal and the second
optical signal; a single laser receiver to receive the single
electric signal and to generate from it a spectrum that corresponds
to both (i) optical feedback of the first laser transmitter, and
(ii) optical feedback of the second laser transmitter.
[0136] In some embodiments, the single monitor photodiode is
separate from both the first laser transmitter and the second laser
transmitter.
[0137] In some embodiments, the first and second laser transmitters
are co-packaged; and wherein the single monitor photodiode is
integrated within the co-packaged and second laser
transmitters.
[0138] In some embodiments, the first and second laser transmitters
are monolithically integrated; and wherein the single monitor
photodiode is also monolithically integrated within the first and
second laser transmitters.
[0139] In some embodiments, the system comprises: a plurality of
laser transmitters that are co-located and co-packaged, wherein all
of said laser transmitters are associated with said single monitor
photodiode that is external to and separate from all said laser
transmitters and is internal to the system.
[0140] In some embodiments, the system comprises: a plurality of
laser transmitters that are monolithically integrated; wherein all
of said laser transmitters are associated with said single monitor
photodiode which is also monolithically integrated within said
laser transmitters.
[0141] In some embodiments, the system comprises: one or more beam
splitters to split outgoing laser beams from said laser
transmitters, and to direct split laser beams towards (i) a target
located externally to the system, and (b) said single monitor
photodiode that is external to all said laser transmitters and is
internal to the system.
[0142] In some embodiments, the system comprises: a first laser
modulator to modulate the first laser transmitter at a first
waveform, and to cause the first laser transmitter to transmit a
first laser beam having the first self-mix carrier; a second,
separate, laser modulator to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0143] In some embodiments, the system comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
utilizes a first electric circuitry to modulate the first laser
transmitter at a first waveform, and to cause the first laser
transmitter to transmit a first laser beam having the first
self-mix carrier; wherein said single, laser modulator utilizes a
second electric circuitry to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0144] In some embodiments, the system comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein the first laser transmitter
has physical diameter of a first value; wherein the second laser
transmitter has physical diameter of a second, greater, value;
wherein, based on the different physical diameters of the first and
second laser transmitters, said first and second laser transmitters
transmit respectively a first laser beam and a second laser beam
having two different self-mix carrier frequencies.
[0145] In some embodiments, the system comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein, by utilizing a Distributed
Bragg Reflector (DBR) doping technique, said first and second laser
transmitters transmit respectively a first laser beam and a second
laser beam having two different self-mix carrier frequencies.
[0146] In some embodiments, the system comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein the first laser transmitter
operates at a first temperature; wherein the second laser
transmitter operates at a second, greater, temperature; wherein,
based on different operational temperatures of the first and second
laser transmitters, said first and second laser transmitters
transmit respectively a first laser beam and a second laser beam
having two different self-mix carrier frequencies.
[0147] In some embodiments, the system comprises: a selective
activation module to selectively activate and de-activate at least
one of the first laser transmitter and the second laser
transmitter.
[0148] In some embodiments, the system comprises: a selective
activation module to selectively de-activate one laser transmitter
out of the first laser transmitter and the second laser
transmitter, based on self-mix usefulness of optical feedback
received by each one of said first and second laser
transmitters.
[0149] In some embodiments, the system comprises: a laser
usefulness estimator to estimate self-mix usefulness of optical
feedback received by the first laser transmitter; a selective
activation module (a) to selectively de-activate the first laser
transmitter and (b) to maintain the second laser transmitter
activated, if an estimated self-mix usefulness value of the first
laser transmitter is below a pre-defined threshold value.
[0150] In some embodiments, the system comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter.
[0151] In some embodiments, the system comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter and
the second laser transmitter are located at a same distance from
said single lens assembly.
[0152] In some embodiments, the system comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter is
located at a first distance from said single lens assembly; wherein
the first laser transmitter is located at a second, different,
distance from said single lens assembly.
[0153] In some embodiments, the system comprises: a spectral
analysis module configured (A) to analyze a spectrum of signals
received by said single laser receiver, and (B) to identify in said
spectrum a first peak and a second peak that correspond,
respectively, to the first laser transmitter and the second laser
transmitter, and (C) to monitor a drift of at least one of said
first peak and said second peak in response to vibration of a
remote speaker that is hit by at least one: a laser beam
transmitted by the first laser transmitter, and a laser beam
transmitted by the second laser transmitter, and (D) to determine
one or more characteristics of vibrations of said remote speaker,
based on said drift monitored in said spectrum.
[0154] In some embodiments, the system comprises a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said system is not in physical contact with
human speaker.
[0155] In some embodiments, the system comprises a hybrid
acoustic-and-optical sensor which includes at least: a laser-based
microphone able to remotely sense vibrations of a facial-area of a
human speaker while said system is not in physical contact with
human speaker; and an acoustic microphone able to capture acoustic
signals generated by said human speaker; wherein the system further
comprises a processor to enhance the acoustic signals, that are
captured by said acoustic microphone, based on vibrations of the
facial-area of the human speaker that are sensed remotely by the
laser-based microphone.
[0156] In some embodiments, the system comprises: a third laser
transmitter having a third self-mix carrier frequency, wherein the
third self-mix carrier frequency is different from the first
self-mix carrier frequency, wherein the third self-mix carrier
frequency is different from the second self-mix carrier frequency;
wherein said single monitor photodiode is to further receive a
third optical signal from the third laser transmitter, and to
output a single electric signal that corresponds to a combination
of the first optical signal and the second optical signal and the
third optical signal; wherein said single laser receiver is to
receive the single electric signal and to generate from it a
spectrum that corresponds to (i) optical feedback of the first
laser transmitter, and (ii) optical feedback of the second laser
transmitter, and (iii) optical feedback of the third laser
transmitter.
[0157] In some embodiments, the system comprises: a plurality of
laser transmitters that are co-located and co-packaged, and are
associated with said single monitor photodiodes; wherein each one
of the laser transmitters has a self-mix carrier frequency that is
different from any other self-mix carrier frequency of any other
laser transmitter of the system; wherein each one of the laser
transmitters provides an optical signal to said single monitor
photodiode; wherein said single monitor photodiode outputs a single
combined electric signal to an entry node of said single
receiver.
[0158] In some embodiments, a sensor comprises: a single laser
transmitter, connected to a single monitor photodiode, connected to
a single laser receiver; a single laser driver and modulator to
modulate said single laser transmitter; an optics element located
between the single laser transmitter and a target; wherein the
single laser transmitter is to output a single laser beam; wherein
the optics element splits said single laser beam into multiple
laser beams that hit said target and multiple, respective, spots;
wherein each of said multiple laser beams is associated with a
single self-mix carrier frequency. In some embodiments, the optics
element comprises at least one of: (a) a diffractive optics
element, (b) a lens array.
[0159] In some embodiments, a device comprises: a first laser
transmitter having a first self-mix carrier frequency; a second
laser transmitter having a second, different, self-mix carrier
frequency; a single monitor photodiode (A) to receive a first
optical signal from the first laser transmitter, (B) to receive a
second optical signal from the second laser transmitter, (C) to
output a single electric signal that corresponds to both the first
optical signal and the second optical signal; a single laser
receiver to receive the single electric signal and to generate from
it a spectrum that corresponds to both (i) self-mix signal of the
first laser transmitter, and (ii) self-mix signal of the second
laser transmitter.
[0160] In some embodiments, the device comprises: a plurality of
laser transmitters that are co-located and co-packaged, wherein all
of said laser transmitters are associated with said single monitor
photodiode that is external to and separate from all said laser
transmitters and is internal to said device.
[0161] In some embodiments, the device comprises: a first laser
modulator to modulate the first laser transmitter at a first
waveform, and to cause the first laser transmitter to transmit a
first laser beam having the first self-mix carrier; a second laser
modulator that is separate from the first laser modulator, wherein
the second laser modulator is to modulate the second laser
transmitter at a second waveform, and to cause the second laser
transmitter to transmit a second laser beam having the second
self-mix carrier.
[0162] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is identical to the second delta-wavelength
to delta-current value of the second laser transmitter.
[0163] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter.
[0164] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.05 and
is not smaller than 0.95.
[0165] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.10 and
is not smaller than 0.90.
[0166] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein the ratio between (I) the first
delta-wavelength to delta-current value of the first laser
transmitter and (II) the second delta-wavelength to delta-current
value of the second laser transmitter, is not greater than 1.20 and
is not smaller than 0.80.
[0167] In some embodiments, the device comprises: a spectral
analysis module configured (A) to analyze a spectrum of signals
received by said single laser receiver, and (B) to identify in said
spectrum a first peak and a second peak that correspond,
respectively, to the first laser transmitter and the second laser
transmitter, and (C) to monitor a frequency shift of at least one
of said first peak and said second peak in response to movement of
a remote target that is hit by at least one of: a laser beam
transmitted by the first laser transmitter, and a laser beam
transmitted by the second laser transmitter, and (D) to determine
one or more characteristics of said remote target, based on said
drift monitored in said spectrum.
[0168] In some embodiments, the single monitor photodiode is
separate from both the first laser transmitter and the second laser
transmitter.
[0169] In some embodiments, the first and second laser transmitters
are co-packaged; and wherein the single monitor photodiode is
integrated within the co-packaged first and second laser
transmitters.
[0170] In some embodiments, the first and second laser transmitters
are monolithically integrated with each other; and wherein the
single monitor photodiode is also monolithically integrated within
the first and second laser transmitters.
[0171] In some embodiments, the first and second laser transmitters
are monolithically integrated with each other; and wherein the
single monitor photodiode is not monolithically integrated within
the first and second laser transmitters.
[0172] In some embodiments, the device comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
utilizes a first electric circuitry to modulate the first laser
transmitter at a first waveform, and to cause the first laser
transmitter to transmit a first laser beam having the first
self-mix carrier; wherein said single laser modulator utilizes a
second electric circuitry to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0173] In some embodiments, the device comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein, by utilizing a Distributed
Bragg Reflector (DBR) doping technique, said first and second laser
transmitters transmit respectively a first laser beam and a second
laser beam having two different self-mix carrier frequencies.
[0174] In some embodiments, the device comprises: a laser
usefulness estimator, to estimate self-mix signal usefulness of the
first laser transmitter, by comparing a quality indicator of the
self-mix signal usefulness of the first laser transmitter to one or
more pre-defined threshold values; a selective activation module
(a) to selectively de-activate the first laser transmitter and (b)
to maintain the second laser transmitter activated, if an estimated
self-mix usefulness value of the first laser transmitter is below a
particular pre-defined threshold value.
[0175] In some embodiments, the device comprises: a laser
usefulness estimator, to estimate self-mix signal usefulness of the
first laser transmitter, by comparing a Root Mean Square (RMS)
amplitude of the self-mix signal of the first laser transmitter to
one or more pre-defined threshold values; a selective activation
module (a) to selectively de-activate the first laser transmitter
and (b) to maintain the second laser transmitter activated, if an
estimated self-mix usefulness value of the first laser transmitter
is below a particular pre-defined threshold value.
[0176] In some embodiments, the device comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter and
the second laser transmitter are located at a same distance from
said single lens assembly.
[0177] In some embodiments, an apparatus device comprises: a first
laser transmitter having a first self-mix carrier frequency; a
second laser transmitter having a second, different, self-mix
carrier frequency; a first monitor photodiode to receive a first
optical signal from the first laser transmitter, and to output a
first electric signal; a second monitor photodiode to receive a
second optical signal from the second laser transmitter, and to
output a second electric signal; an electric connection to connect
together the first electric signal and the second electric signal,
forming a combined electric signal; a single laser receiver to
receive the combined electric signal and to generate from it a
spectrum that corresponds to both (i) self-mix signal of the first
laser transmitter, and (ii) self-mix signal of the second laser
transmitter.
[0178] In some embodiments, the first monitor photodiode is
separate from the second monitor photodiode; wherein the first and
second monitor photodiodes, and the first and second laser
transmitters, and the single laser receiver, are co-located within
a same packaging.
[0179] In some embodiments, said electric connection, that connects
together the first and second electric signals, is an electric
connection located externally to the single laser receiver and is
located prior to an entry node of the single laser receiver.
[0180] In some embodiments, the apparatus comprises: a first laser
modulator to modulate the first laser transmitter at a first
waveform, and to cause the first laser transmitter to transmit a
first laser beam having the first self-mix carrier; a second,
separate, laser modulator to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0181] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
utilizes a first electric circuitry to modulate the first laser
transmitter at a first waveform, and to cause the first laser
transmitter to transmit a first laser beam having the first
self-mix carrier; wherein said single, laser modulator utilizes a
second electric circuitry to modulate the second laser transmitter
at a second waveform, and to cause the second laser transmitter to
transmit a second laser beam having the second self-mix
carrier.
[0182] In some embodiments, the apparatus comprises: a selective
activation module to selective de-activate one laser transmitter
out of the first laser transmitter and the second laser
transmitter, and to increase a Signal to Noise Ratio (SNR) of the
apparatus, based on a comparison between: (i) estimated usefulness
of self-mix signal of the first laser transmitter, and (ii)
estimated usefulness of self-mix signal of the second laser
transmitter.
[0183] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter and
the second laser transmitter are located at a same distance from
said single lens assembly.
[0184] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter is
located at a first distance from said single lens assembly; wherein
the first laser transmitter is located at a second, smaller,
distance from said single lens assembly.
[0185] In some embodiments, the apparatus comprises: a spectral
analysis module configured (A) to analyze a spectrum of signals
received by said single laser receiver, and (B) to identify in said
spectrum a first peak and a second peak that correspond,
respectively, to the first laser transmitter and the second laser
transmitter, and (C) to monitor a frequency shift of at least one
of said first peak and said second peak in response to movement of
a remote target that is hit by at least one of: a laser beam
transmitted by the first laser transmitter, and a laser beam
transmitted by the second laser transmitter, and (D) to determine
one or more characteristics of speed of said remote target, based
on said drift monitored in said spectrum.
[0186] In some embodiments, the apparatus comprises (or is) a
laser-based microphone able to remotely sense vibrations of a
facial-area of a human speaker while said apparatus is not in
physical contact with said human speaker.
[0187] In some embodiments, the apparatus comprises (or is) a
laser-based microphone able to remotely sense vibrations of a
facial-area of a human speaker while said apparatus is not in
physical contact with human speaker; wherein the apparatus is
embedded within a vehicular component of a vehicle in which said
human speaker is located.
[0188] In some embodiments, the apparatus comprises (or is) a
hybrid acoustic-and-optical sensor which includes at least: a
laser-based microphone able to remotely sense vibrations of a
facial-area of a human speaker while said apparatus is not in
physical contact with human speaker; and an acoustic microphone
able to capture acoustic signals generated by said human speaker;
wherein the apparatus further comprises a processor to enhance the
acoustic signals, that are captured by said acoustic microphone,
based on vibrations of the facial-area of the human speaker that
are sensed remotely by the laser-based microphone.
[0189] In some embodiments, the electric connection that connects
together the first electric signal and the second electric signal,
and forms the combined electric signal, is an electric connection
located after the entry node of said single laser receiver, and
wherein each of the first and second electric signals is
pre-amplified before reaching said electric connection.
[0190] In some embodiments, the apparatus comprises: a single laser
modulator connected to both the first laser transmitter and the
second laser transmitter; wherein said single laser modulator
provides a same modulation to both the first laser transmitter and
the second laser transmitter; wherein, by utilizing a Distributed
Bragg Reflector (DBR) doping technique, said first and second laser
transmitters transmit respectively a first laser beam and a second
laser beam having two different self-mix carrier frequencies.
[0191] In some embodiments, the first laser transmitter has a first
delta-wavelength to delta-current value, which indicates a change
in wavelength of a laser beam that is transmitted by the first
laser transmitter as a function of a change in current supplied to
said first laser transmitter; wherein the second laser transmitter
has a second delta-wavelength to delta-current value, which
indicates a change in wavelength of a laser beam that is
transmitted by the second laser transmitter as a function of a
change in current supplied to said second laser transmitter;
wherein the first delta-wavelength to delta-current value of the
first laser transmitter is non-identical to the second
delta-wavelength to delta-current value of the second laser
transmitter; wherein at least the first delta-wavelength to
delta-current value, of the first laser transmitter, is modifiable
by modifying a Direct Current (DC) that is supplied to said first
laser transmitter.
[0192] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter is
located at a first distance from said single lens assembly; wherein
the first laser transmitter is located at a second, greater,
distance from said single lens assembly.
[0193] In some embodiments, the apparatus comprises: a single lens
assembly that is common to both the first laser transmitter and the
second laser transmitter; wherein the first laser transmitter is
located at a first distance from said single lens assembly; wherein
the first laser transmitter is located at a second, greater,
distance from said single lens assembly.
[0194] Functions, operations, components and/or features described
herein with reference to one or more embodiments of the present
invention, may be combined with, or may be utilized in combination
with, one or more other functions, operations, components and/or
features described herein with reference to one or more other
embodiments of the present invention. The present invention may
thus comprise any possible or suitable combinations,
re-arrangements, assembly, re-assembly, or other utilization of
some or all of the modules or functions or components that are
described herein, even if they are discussed in different locations
or different chapters of the above discussion, or even if they are
shown across different drawings or multiple drawings.
[0195] While certain features of some demonstrative embodiments of
the present invention have been illustrated and described herein,
various modifications, substitutions, changes, and equivalents may
occur to those skilled in the art. Accordingly, the claims are
intended to cover all such modifications, substitutions, changes,
and equivalents.
* * * * *