U.S. patent application number 12/255227 was filed with the patent office on 2010-04-22 for fiber optic optical subassembly configuration.
Invention is credited to Mark William Barenek, Michael J. Hackert.
Application Number | 20100097600 12/255227 |
Document ID | / |
Family ID | 42108396 |
Filed Date | 2010-04-22 |
United States Patent
Application |
20100097600 |
Kind Code |
A1 |
Barenek; Mark William ; et
al. |
April 22, 2010 |
Fiber Optic Optical Subassembly Configuration
Abstract
A fiber optic optical subassembly configuration for monitoring
fibers. The configuration includes a hollow container, a laser for
emitting laser signals towards the fibers being monitored, a
photodetector for monitoring reflected laser signals from the
fibers being monitored and for monitoring laser output power, a
beam splitter and an optical fiber. The optical fiber, disposed
within the hollow container, has a coated end face surface, the
laser emits signals toward and through the beam splitter, whereby a
portion of the laser signal illuminates the photodetector, and
another portion traverses down the optical fiber toward the coated
end face surface and reflects off the coated end face surface
toward the fibers that are being monitored, and reflects back from
the fibers being monitored to the photodetector such that faults on
the fibers can be detected.
Inventors: |
Barenek; Mark William;
(Leonardtown, MD) ; Hackert; Michael J.;
(Lexington Park, MD) |
Correspondence
Address: |
Department of the Navy;(Naval Air Warfare Center -Aircraft Division)
47076 Lijencreantz Road, B 435
PATUXENT RIVER
MD
20670
US
|
Family ID: |
42108396 |
Appl. No.: |
12/255227 |
Filed: |
October 21, 2008 |
Current U.S.
Class: |
356/73.1 |
Current CPC
Class: |
G01M 11/35 20130101 |
Class at
Publication: |
356/73.1 |
International
Class: |
G01N 21/00 20060101
G01N021/00 |
Goverment Interests
STATEMENT OF GOVERNMENT INTEREST
[0002] The invention described herein may be manufactured and used
by or for the Government of the United States of America for
governmental purposes without payment of any royalties thereon or
therefor.
Claims
1. A fiber optic optical subassembly configuration for monitoring
fibers, the configuration comprising: a hollow container, the
container having an axis and an outer circumference; a laser for
emitting laser signals towards the fibers being monitored, the
laser disposed along the outer circumference of the container; a
photodetector for monitoring reflected laser signals from the
fibers being monitored and for monitoring laser output power, the
photodetector disposed along the outer circumference of the
container, the photodetector substantially disposed diametrically
opposite to the laser; a beam splitter, the beam splitter disposed
within the container; an optical fiber, the optical fiber embedded
in the container and substantially parallel to the aids of the
container, the optical fiber disposed substantially perpendicular
to the laser signal emitted by the laser, the optical fiber having
a coated end face surface, the laser emitting signals toward and
trough the beam splitter, whereby a portion of the laser signal
illuminates the photodetector, and another portion traversing down
the optical fiber toward the coated end face surface and reflecting
off the coated end face surface toward the fibers that are being
monitored, and reflecting back from the fibers being monitored to
the photodetector such that faults on the fibers can be
detected.
2. The configuration of claim 1, wherein the container includes
lenses disposed between the container and the photodetector and
between the container and the laser.
3. The configuration of claim 1, wherein the laser is a vertical
cavity surface emitting laser.
4. A fiber optic optical subassembly configuration for monitoring
fibers, the configuration comprising: a lens, the lens having an
axis and an outer diameter; a laser for emitting laser signals
towards the fibers being monitored, the laser disposed along the
outer diameter of the lens; a photodetector for monitoring
reflected laser signals from the fibers being monitored and for
monitoring laser output power, the photodetector disposed along the
outer diameter of the lens, the photodetector disposed
substantially diametrically opposite to the laser; a beam splitter,
the beam splitter disposed within the lens; an optical fiber, the
optical fiber embedded in the lens and substantially parallel to
the axis of the lens, the optical fiber disposed perpendicularly to
the laser signal emitted by the laser, the optical fiber having a
coated end face surface, the laser emitting signals toward and
through the beam splitter, whereby a portion of the laser signal
illuminates the photodetector, and another portion traversing down
the optical fiber toward the mirrored end face surface and
reflecting off the coated end face surface toward the fibers that
are being monitored, and reflecting back from the fibers being
monitored to the photodetector such that faults on the fibers can
be detected.
5. The configuration of claim 4, wherein the lens is cylindrically
shaped.
6. The configuration of claim 5, wherein the lens is manufactured
from glass.
7. The configuration of claim 5, wherein the lens is manufactured
from quartz.
8. The configuration of claim 5, wherein the lens is a GRIN
lens.
9. The configuration of claim 8, wherein the photodetector is a
positive-intrinsic-negative photodetector.
10. The configuration of claim 9, wherein the configuration further
includes a laser driver circuit for providing current to the
laser.
11. The configuration of claim 10, wherein the laser is a vertical
cavity surface emitting laser.
12. The configuration of claim 11, wherein the optical fiber is a
multimode optical fiber transmitting in about the 800 to 1600 nm
range.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The above listed invention is hereby cross referenced and
related to U.S. patent application Ser. No. 11/789,120, filed Apr.
25, 2007, entitled "Transceiver Optical Subassembly" by inventor
Mark W. Beranek; U.S. patent application Ser. No. 11/789,121, filed
Apr. 25, 2007, entitled "Hybrid Fiber Optic Transceiver Optical
Subassembly" by inventor Mark W. Beranek; and U.S. patent
application Ser. No. 11/900,143, filed Sep. 5, 2007, entitled
"Optical Bench Fiber Optic Transmitter" by inventor Mark W.
Beranek. U.S. patent application Ser. Nos. 11/789,120, 11/789,121
and 11/900,143 are not admitted to be prior art with respect to the
present invention. The applications are hereby incorporated by
reference. All inventions are assigned to the same assignee and
have a common inventor.
BACKGROUND
[0003] The present invention relates to a fiber optic optical
subassembly configuration. More specifically, but without
limitation, the present invention relates to a micro-optic based
fiber optic beam splitter for reflectometry that can be used for
monitoring fibers.
[0004] Previous methods have not enabled laser diode
monitoring.
[0005] For the foregoing reasons, there is a need for monitoring
the output power of the laser diode.
SUMMARY
[0006] The present invention is directed to a transmitter or
subassembly that meets the needs enumerated above and below.
[0007] The present invention is directed to a fiber optic optical
subassembly configuration for monitoring fibers. The configuration
includes a hollow container, a laser for emitting laser signals
towards the fibers being monitored, a photodetector for monitoring
reflected laser signals from the fibers being monitored and for
monitoring laser output power, a beam splitter and an optical
fiber. The container has an axis and an outer circumference. The
laser is disposed along or outside the outer circumference of the
container, and the photodetector is disposed along or outside the
outer circumference of the container. The photodetector is disposed
in a position that is substantially diametrically opposed or
opposite to the laser. The beam splitter is disposed within the
container; and the optical fiber is embedded in the container and
substantially parallel to the axis of the container. The optical
fiber is disposed perpendicularly to the laser signal emitted by
the laser. The optical fiber has a coated end face surface, the
laser emits signals toward and through the beam splitter, whereby a
portion of the laser signal illuminates the photodetector, and
another portion traverses down the optical fiber toward the coated
end face surface and reflects off the coated end face surface
toward the fibers that are being monitored, and reflects back from
the fibers being monitored to the photodetector such that faults on
the fibers can be detected.
[0008] It is a feature of the present invention to provide a fiber
optic optical subassembly configuration that allows vertical cavity
surface emitting laser power monitoring and/or edge emitting laser
diode power monitoring.
[0009] It is a feature of the present invention to provide a fiber
optic optical subassembly configuration that can accurately locate
and isolate faults in fiber optic cables and/or fiber optic
transceivers.
DRAWINGS
[0010] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims, and accompanying
drawing wherein:
[0011] FIG. 1 is a cross sectional view of the fiber optic optical
subassembly configuration.
DESCRIPTION
[0012] The preferred embodiments of the present invention are
illustrated by way of example below and in FIG. 1. As seen in FIG.
1, the fiber optic optical subassembly configuration 10 for
monitoring fibers 50 includes a hollow container 100, a laser 200
for emitting laser signals towards the fibers 50 being monitored, a
photodetector 300 for monitoring reflected laser signals from the
fibers 50 being monitored and for monitoring laser output power, a
beam splitter 400 and an optical fiber 500. The container 100 has
an axis 110 and an outer circumference 105. The laser 200 is
disposed along or outside the outer circumference 105 of the
container 100, and the photodetector 300 is also disposed along or
outside the outer circumference 105 of the container 100. The
photodetector 300 is disposed in a position substantially
diametrically opposed to the laser 200 (disposed opposite from each
other along the outer circumference 105 of the container 100). The
beam splitter 400 is disposed within the container 100 (preferably
on or within the optical fiber 500); and the optical fiber 500 is
embedded in the container 100 and substantially parallel to the
axis 110 of the container 100. In one of the embodiments of the
invention, the optical fiber 500 and the container 100 are axially
aligned. The optical fiber 500 is disposed substantially
perpendicular to the initial laser signal 210 emitted by the laser
200. The optical fiber 500 has a coated end face surface 505, the
laser 200 emits signals 210 toward and through the beam splitter
400, whereby a portion of the laser signal illuminates the
photodetector 300 (the photodetector portion signal 215), and
another portion traverses down the optical fiber 500 toward the
coated end face surface 505 (the coated end face surface portion
signal 220) and reflects off the coated end face surface 505 along
(or substantially parallel to) the axis 110 of the optical fiber
500 toward the fibers 50 that are being monitored (the reflected
coated end face surface portion signal 225), and reflects back from
the fibers 50 being monitored along the optical fiber 500 and via
the beam splitter 400 to the photodetector 300 (the fiber reflected
portion signal 230) such that faults on the fibers 50 can be
detected. Micro-optic lenses 600 or any other type of lenses may be
placed between the photodetector 300 and the container 100 and
between the laser 200 and the container 100 to maximize light
coupling efficiency between the laser 200, photodetector 300 and
optical fiber 500.
[0013] In the description of the present invention, the invention
will be discussed in an avionic or aircraft fiber link environment;
however, this invention can be utilized for any type of need that
requires use of a optical subassembly configuration. The
configuration 10 may be used, but without limitations, in military
operations, communications, and various other electronic uses.
Additionally, the same techniques and/or subassembly described here
for laser diodes can be applied to surface emitting and edge
emitting LEDs, as well as other types of lasers.
[0014] The container 100 may be a cylinder, a tube, a rectangular
box or any type of shape practicable. The hollow container 100 may
be a container with lenses disposed at its ends. The container may
be manufactured from glass or quartz or may be a cylindrical GRIN
lens. A GRIN lens is, but without limitation, a lens whose material
refractive index varies continuously as a function of spatial
coordinates in the medium. In another embodiment of the invention,
the entire container 100 may be a lens with the elements disposed
within the lens itself (as described above in a GRIN lens). In
another embodiment of the invention, a portion of the photodector
may be swapped with a fiber.
[0015] A laser 200 may be defined, but without limitation, as a
light source producing, through stimulated emission, coherent, near
monochromatic light, or light amplification by stimulated emission
of radiation. One embodiment of the invention includes a laser 200
that is a vertical cavity surface emitting laser (VCSEL). A
vertical cavity surface emitting laser (VCSEL) is typically, but
without limitation, a specialized laser diode (a laser diode, also
known as an injection laser or diode laser, may be defined, but
without limitation, as a semiconductor device that produces
coherent radiation (in which the waves are all at the same
frequency and phase) in the visible or infrared (IR) spectrum when
current passes through it). The configuration 10 may also include a
laser driver circuit 700. The laser driver circuit 700 provides
current to the laser 200 such that the laser 200 emits signals,
specifically optical signals or light.
[0016] A photodetector 300 may be defined, but without limitation,
as a device capable of sensing light and converting it to
electricity. The photodetector 300 may be a
positive-intrinsic-negative (p-i-n) photodetector, either front
illuminated or back illuminated, a metal-semiconductor-metal (MSM),
or an avalanche photodiode or photodetector. However, any type of
photodetector can be utilized, as practicable.
[0017] A beam splitter 400 is an optical device that splits a beam
of light in two. The beam splitter 400 may be a polished plane that
is angled or oblique to the axis of the optical fiber 500, and acts
as a beam splitter. However, any type of conventional beam splitter
may be utilized.
[0018] An optical fiber 500 may be defined, but without limitation
as, a waveguide medium used to transmit information via light
impulses rather than through the movement of electrons. The
preferred optical fiber 500 is a multimode optical fiber
transmitting in the about 800 to about 1600 nm range. The coated
end face surface 505 may be defined, but without limitation, as a
polished plane that is a reflective thin film material.
[0019] When introducing elements of the present invention or the
preferred embodiment(s) thereof, the articles "a," "an," "the," and
"said" are intended to mean there are one or more of the elements.
The terms "comprising," "including," and "having" are intended to
be inclusive and mean that there may be additional elements other
than the listed elements.
[0020] Although the present invention has been described in
considerable detail with reference to a certain preferred
embodiments thereof, other embodiments are possible. Therefore, the
spirit and scope of the appended claims should not be limited to
the description of the preferred embodiment(s) contained
herein.
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