U.S. patent application number 11/293931 was filed with the patent office on 2006-06-08 for microscope.
This patent application is currently assigned to Jasco Corporation. Invention is credited to Jun Koshoubu.
Application Number | 20060119856 11/293931 |
Document ID | / |
Family ID | 36573796 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060119856 |
Kind Code |
A1 |
Koshoubu; Jun |
June 8, 2006 |
Microscope
Abstract
A microscope comprising: a light sampler for collecting light
from a measurement area of a sample; a multi-element detector
having a plurality of photoelectric elements, for detecting the
light collected by the light sampler, each photoelectric element
corresponding to a minute measurement region in the measurement
area with one-to-one correspondence; a Fourier transform
spectrophotometer as a spectroscope; a data sampler for
concurrently sampling intensity data sent from each photoelectric
element of the multi-element detector at a timing determined by the
Fourier transform spectrophotometer; and a data processor for
obtaining time-resolved spectrum data for each minute measurement
region according to temporally changed interference light data
obtained by the data sampler.
Inventors: |
Koshoubu; Jun;
(Hachioji-shi, JP) |
Correspondence
Address: |
RANKIN, HILL, PORTER & CLARK, LLP
925 EUCLID AVENUE, SUITE 700
CLEVELAND
OH
44115-1405
US
|
Assignee: |
Jasco Corporation
Hachioji-shi
JP
|
Family ID: |
36573796 |
Appl. No.: |
11/293931 |
Filed: |
December 5, 2005 |
Current U.S.
Class: |
356/451 |
Current CPC
Class: |
G01J 3/453 20130101;
G01J 3/2889 20130101; G02B 21/0096 20130101 |
Class at
Publication: |
356/451 |
International
Class: |
G01B 9/02 20060101
G01B009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2004 |
JP |
2004-352556 |
Claims
1. A microscope comprising: a light sampler for collecting light
from a measurement area of a sample; a multi-element detector
having a plurality of photoelectric elements, for detecting the
light collected by the light sampler, each photoelectric element
corresponding to a minute measurement region in the measurement
area with one-to-one correspondence; a Fourier transform
spectrophotometer having a moving mirror serving as an optical path
difference generator in an interferometer, the Fourier transform
spectrophotometer serving as a spectroscope for light incident on
the measurement area and/or light coming from the measurement area;
a data sampler for concurrently sampling intensity data sent from
each photoelectric element of the multi-element detector at a
timing determined according to position information of the moving
mirror, which is sent from the Fourier transform spectrophotometer;
and a data processor for obtaining time-resolved spectrum data for
each minute measurement region according to temporally changed
interference light data obtained by the data sampler.
2. A microscope according to claim 1, wherein the plurality of
photoelectric elements of the multi-element detector is placed in
one dimension.
3. A microscope according to claim 1, wherein the Fourier transform
spectrophotometer continuously moves the moving mirror at a high
speed in a rapid-scanning mode; the data sampler concurrently
samples the intensity data sent from each photoelectric element of
the multi-element detector every time the moving mirror is moved by
a constant distance, starting at a predetermined position; and the
data processor obtains the temporally changed interference light
data according to intensity data at each sampling position in the
rapid-scanning mode and further obtains the time-resolved spectrum
data, for each minute measurement region.
4. A microscope according to claim 1, wherein the Fourier transform
spectrophotometer discretely moves the moving mirror in a step-like
manner in a step-scanning mode in order to perform time-resolved
measurement for a periodic reaction; the data sampler concurrently
samples the intensity data sent from each photoelectric element of
the multi-element detector at each stop position of the moving
mirror in the step-scanning mode every time a predetermined time
elapses, starting at the beginning of the periodic reaction; and
the data processor obtains the temporally changed interference
light data according to intensity data at each elapsed time,
starting at the beginning of the periodic reaction and further
obtains the time-resolved spectrum data, for each minute
measurement region.
5. A microscope according to claim 1, further comprising a
measurement-area moving unit for moving the measurement area, the
measurement-area moving unit comprising: a stage on which the
sample is placed; a stage driver for moving the stage horizontally;
and a stage controller for controlling the movement of the stage
performed by the stage driver, wherein the measurement area in the
sample is moved by the movement of the stage, where the sample is
placed.
Description
RELATED APPLICATIONS
[0001] This application claims priority to the Japanese Patent
Application 2004-352556 dated on Dec. 6, 2004 and is hereby
incorporated with reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to microscopes, and more
particularly, to a mechanism therein for obtaining a time-resolved
spectrum.
[0004] 2. Prior Art
[0005] Time-resolved measurement apparatuses are used to measure
temporal changes in samples. In the time-resolved measurement
apparatuses, the entire sample is illuminated with interference
light sent from an interferometer, and interference light coming
from the sample is detected to obtain the temporally changed
spectrum (for example, see Japanese Unexamined Patent Application
Publication No. Hei-5-223640).
[0006] Recently, time-resolved measurement is also demanded for
microscopes that perform imaging analysis of minute measurement
regions.
[0007] In time-resolved measurement, it is necessary to measure
spectra that change, for example, in microseconds to nanoseconds.
To follow such spectral changes, the measurement speed of
microscopes needs to be improved, but conventionally, there have
been no technologies to make such an improvement.
SUMMARY OF THE INVENTION
[0008] The present invention was conceived in light of the above
problem of the prior art, and the object thereof is to provide a
microscope that can obtain time-resolved spectrum.
[0009] The microscope of the present invention to achieve the above
object is a microscope comprises a light sampler and a
multi-element detector. The multi-element detector has a plurality
of photoelectric elements, each photoelectric element corresponding
to a minute measurement region in the measurement area with
one-to-one correspondence. The microscope comprises a Fourier
transform spectrophotometer, a data sampler and a data
processor.
[0010] The microscope unit collects light from a measurement area
of a sample.
[0011] The multi-element detector has a plurality of photoelectric
elements, detects the light collected by the light sampler.
[0012] The Fourier transform spectrophotometer has a moving mirror
serving as an optical path difference generator in an
interferometer. The Fourier transform spectrophotometer serves as a
spectroscope for light incident on the measurement area and/or
light coming from the measurement area.
[0013] The data sampler concurrently samples intensity data sent
from each photoelectric element of the multi-element detector at a
timing determined according to position information of the moving
mirror, which is sent from the Fourier transform
spectrophotometer.
[0014] The data processor obtains time-resolved spectrum data for
each minute measurement region according to temporally changed
interference light data obtained by the data sampler.
Multi-Element Detector
[0015] In this invention, it is preferred that the plurality of
photoelectric elements of the multi-element detector is placed in
one dimension.
[0016] This is because such a structure is advantageous in that
intensity data from each photoelectric element can be concurrently
sampled at a higher speed.
Rapid-Scanning Mode
[0017] In this invention, the Fourier transform spectrophotometer
continuously moves the moving mirror at a high speed in a
rapid-scanning mode. The data sampler concurrently samples the
intensity data sent from each photoelectric element of the
multi-element detector every time the moving mirror is moved by a
constant distance, starting at a predetermined position. The data
processor obtains the temporally changed interference light data
according to intensity data at each sampling position in the
rapid-scanning mode and further obtains the time-resolved spectrum
data, for each minute measurement region.
Step-Scanning Mode
[0018] In this invention, the Fourier transform spectrophotometer
discretely moves the moving mirror in a step-like manner in a
step-scanning mode in order to perform time-resolved measurement
for a periodic reaction. The data sampler concurrently samples the
intensity data sent from each photoelectric element of the
multi-element detector at each stop position of the moving mirror
in the step-scanning mode every time a predetermined time elapses,
starting at the beginning of the periodic reaction. The data
processor obtains the temporally changed interference light data
according to intensity data at each elapsed time, starting at the
beginning of the periodic reaction and further obtains the
time-resolved spectrum data, for each minute measurement
region.
Measurement-Area Moving Unit
[0019] In this invention, the microscope further comprises a
measurement-area moving unit for moving the measurement area. The
measurement-area moving unit comprises a stage, a stage driver and
a stage controller. The measurement area in the sample is moved by
the movement of the stage.
[0020] The stage on which the sample is placed.
[0021] The stage driver moves the stage horizontally.
[0022] The stage controller controls the movement of the stage
performed by the stage driver.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a view showing an outlined structure of an
infrared microscope according to an embodiment of the present
invention.
[0024] FIG. 2 is a view showing the acquisition of a time-resolved
spectrum performed when a Fourier transform spectrophotometer shown
in FIG. 1 operates in a rapid-scanning mode.
[0025] FIGS. 3A to 3C are views showing the acquisition of a
time-resolved spectrum performed when the Fourier transform
spectrophotometer shown in FIG. 1 operates in a step-scanning
mode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] A preferred embodiment will be described below by referring
to the drawings.
[0027] FIG. 1 shows an outlined structure of a multi-channel
infrared microscope 10 according to an embodiment of the present
invention.
[0028] In addition to an infrared microscope having a microscope
unit (light sampler) 12 and a multi-element infrared detector
(multi-element detector) 14, the multi-channel infrared microscope
(microscope) 10 includes a Fourier transform infrared
spectrophotometer (FTIR) 16, a sampling circuit (data sampler) 18,
and a data processor 20.
[0029] The microscope unit 12 illuminates a measurement area of a
sample 22 with interference light 24 and obtains interference light
26 coming from the measurement area.
[0030] The multi-element infrared detector 14 has a plurality of
photoelectric elements disposed in one dimension and detects the
interference light 26 coming from the measurement area.
[0031] An advantageous feature of the present invention is that a
temporal change in each minute measurement region of the sample 22
can be measured in the infrared microscope of the multi-channel
infrared microscope 10. To obtain this feature, as described above,
the multi-element infrared detector 14 provided for the infrared
microscope is combined with the Fourier transform infrared
spectrophotometer 16 in the present embodiment. In addition, the
sampling circuit 18 is provided in the present embodiment.
[0032] In the present embodiment, each photoelectric element in the
multi-element infrared detector 14 handles a minute measurement
region in the measurement area with one-to-one correspondence. The
multi-element infrared detector 14 used in the present embodiment
has a plurality of photoelectric elements disposed in one dimension
because this allows intensity data to be sampled from the
photoelectric elements more concurrently at a higher speed.
[0033] The Fourier transform infrared spectrophotometer 16 has a
moving mirror 27. A moving mirror driver 28 and a moving mirror
controller 29 are used to operate the moving mirror 27 in a
rapid-scanning mode and a step-scanning mode.
[0034] The Fourier transform infrared spectrophotometer 16 further
includes an infrared light source 30, a main interferometer 32, and
a position detector 34 for obtaining position information of the
moving mirror 27. The position detector 34 includes a He--Ne laser
36, a control interferometer 38 also serving as the main
interferometer 32, and a He--Ne detector 40.
[0035] The sampling circuit 18 samples intensity data at a high
speed from each photoelectric element of the multi-element infrared
detector 14 concurrently by the use of a sampling timing generator
41.
[0036] The data processor 20 includes, for example, a computer 33
and obtains time-resolved spectrum data of each minute measurement
region according to temporally changed interference light data sent
from the sampling circuit 18.
[0037] In the present embodiment, a stage 42, a stage driver 44,
and a stage controller 46 are also provided. The sample 22 is
placed on the stage 42, and the stage 42 is moved to move the
measurement area of the sample 22.
[0038] The stage driver 44 moves the stage 42 horizontally. The
stage controller 46 controls the movement of the stage 42 performed
by the stage driver 44.
[0039] In the present embodiment, microscopic measurement of
temporal changes can be performed accurately, which was very
difficult to conduct in conventional infrared microscopes.
[0040] Conventionally, a multi-element infrared detector is used to
obtain temporally changed interference light data of one
measurement area in a time-sequential manner. More specifically,
the photoelectric elements of the multi-element infrared detector
are sequentially scanned to output intensity data corresponding to
each photoelectric element in a time-sequential manner. Based on
the time-sequential data obtained in this way, temporally changed
spectrum data of the entire sample is obtained.
[0041] In contrast, in the present embodiment, to obtain temporally
changed spectrum data of each minute measurement region in a
sample, a combination of an existing multi-element infrared
detector in an infrared microscope and a Fourier transform infrared
spectrophotometer is employed.
<Multi-Element Infrared Detector>
[0042] In the present embodiment, the multi-element infrared
detector 14 is used not to obtain intensity data of the entire
sample in a time-sequential manner but to obtain a surface
intensity distribution. Each photoelectric element of the
multi-element infrared detector 14 corresponds to one minute
measurement region of the measurement area with one-to-one
correspondence.
<Sampling>
[0043] In the present embodiment, the sampling circuit 18 is used
not to sequentially scan the photoelectric elements of the
multi-element infrared detector but to concurrently sample data
from each photoelectric element at a timing determined by the
Fourier transform infrared spectrophotometer.
<Data Processing>
[0044] In the present embodiment, the data processor 20 obtains
temporally changed interference light data from intensity data of
each minute measurement region of the measurement area, obtained by
the sampling circuit 18. The data processor 20 applies a Fourier
transform to the temporally changed interference light data for
each minute measurement region of the measurement area to obtain
time-resolved spectrum data.
[0045] As a result, a temporal change in each minute measurement
region of the sample 22 can be measured in the present
embodiment.
Rapid-Scanning Mode
[0046] The acquisition of a time-resolved spectrum in the
rapid-scanning mode of the moving mirror 27 will be described
next.
[0047] The Fourier transform infrared spectrophotometer 16
continuously moves the moving mirror 27 at a high speed.
[0048] The sampling circuit 18 concurrently samples intensity data
from each photoelectric element of the multi-element infrared
detector 14 every time the moving mirror 27 moves by a constant
distance, starting at a predetermined position. The zero-crossing
points of a laser interference signal (position information of the
moving mirror 27) obtained from the position detector 34 and the
sampling timing generator 41 are used as timing points sent from
the Fourier transform infrared spectrophotometer 16, which are used
to control the sampling of the intensity data.
<Data Processing>
[0049] The data processor 20 obtains temporally changed
interference light data from the intensity data for each minute
measurement region at each sampling position in the rapid-scanning
mode. The data processor 20 applies a Fourier transform to the
temporally changed interference light data to obtain time-resolved
spectrum data.
[0050] The acquisition of the time-resolved spectrum data will be
described more specifically by referring to FIG. 2.
[0051] In FIG. 2, photoelectric elements 50a to 50c of the
multi-element infrared detector 14 correspond to minute measurement
regions 54a to 54c of a measurement area 52 with one-to-one
correspondence.
[0052] The photoelectric element 50a samples the intensity of
interference light 26a coming from the minute measurement region
54a. The photoelectric element 50b samples the intensity of
interference light 26b coming from the minute measurement region
54b. The photoelectric element 50c samples the intensity of
interference light 26c coming from the minute measurement region
54c.
<Sampling>
[0053] In the present embodiment, at time t.sub.1 from the start of
sampling, for example, intensity data I.sub.a1 from the
photoelectric element 50a, intensity data I.sub.b1 from the
photoelectric element 50b, and intensity data I.sub.c1 from the
photoelectric element 50c are concurrently sampled at a high speed.
This operation is performed at a predetermined number of points
every time the moving mirror 27 is moved by the constant distance.
At time t.sub.n, intensity data I.sub.an from the photoelectric
element 50a, intensity data I.sub.bn from the photoelectric element
50b, and intensity data I.sub.cn from the photoelectric element 50c
are concurrently sampled at a high speed. This operation is
performed at the predetermined number of points every time the
moving mirror 27 is moved by the constant distance.
[0054] With the foregoing sampling, n temporally changed
interference light data items are obtained at constant time
intervals for each minute measurement region.
<Data Processing>
[0055] The computer 33 obtains the temporally changed interference
light data for each minute measurement region as described
above.
[0056] The computer 33 then applies a Fourier transform to each of
the n temporally changed interference light data items obtained at
constant time intervals (at t.sub.1, t.sub.2, . . . , and t.sub.n)
for each minute measurement region to obtain time-resolved spectrum
data.
[0057] The computer 33 applies a Fourier transform to interferogram
data 56a corresponding to the minute measurement region 54a to
obtain time-resolved spectrum data 58a. The computer 33 applies a
Fourier transform to interferogram data 56b corresponding to the
minute measurement region 54b to obtain time-resolved spectrum data
58b. The computer 33 applies a Fourier transform to interferogram
data 56c corresponding to the minute measurement region 54c to
obtain time-resolved spectrum data 58c.
[0058] As described above, according to the multi-channel infrared
microscope 10 of the present embodiment, microscopic measurement of
temporal changes can be performed in the form of images. The
above-described time-resolved measurement is performed in the
present embodiment with the use of the infrared microscope having
the multi-element infrared detector 14, and the Fourier transform
infrared spectrophotometer 16 capable of rapid scanning. As a
result, in the rapid scanning mode, a surface distribution can be
obtained in time-resolved measurement of millisecond-order for
one-time reactions.
Step Scanning Mode
[0059] In the present embodiment, it is preferred as described
above that the moving mirror 27 be operated in the rapid scanning
mode. It is also preferred that the step scanning mode be used to
measure a temporal change of periodic reactions.
[0060] Conventionally, in the step scanning mode, intensity data
obtained from all elements of a multi-element infrared detector is
sequentially scanned at each stop position of a moving mirror to
obtain intensity data corresponding to each element in a
time-sequential manner. The time-resolved spectrum data of the
entire sample is obtained from the intensity data obtained in that
way.
[0061] In contrast, in the present embodiment, to obtain
time-resolved spectrum data not for the entire sample but for each
minute measurement region, it is preferred that the following
time-resolved measurement be performed.
[0062] The acquisition of a time-resolved spectrum in the
step-scanning mode of the moving mirror 27 of the interferometer
will be described next, specifically by referring to FIG. 3A to
FIG. 3C.
[0063] The Fourier transform infrared spectrophotometer 16 moves
the moving mirror 27 discretely in a step-like manner.
<Sampling>
[0064] The sampling circuit 18 concurrently samples intensity data
from each photoelectric element of the multi-element infrared
detector 14 at each stop position of the moving mirror 27 at
predetermined time intervals, starting at the beginning of a
periodic reaction.
[0065] At a stop position P.sub.1 of the moving mirror 27, as shown
in FIG. 3A, intensity data I.sub.a1 from the photoelectric element
50a, intensity data I.sub.b1 from the photoelectric element 50b,
and intensity data I.sub.c1 from the photoelectric element 50c are
concurrently measured at predetermined time intervals, starting at
the beginning of the periodic reaction.
[0066] At a stop position P.sub.n of the moving mirror 27, as shown
in FIG. 3B, intensity data I.sub.an from the photoelectric element
50a, intensity data I.sub.bn from the photoelectric element 50b,
and intensity data I.sub.cn from the photoelectric element 50c are
concurrently measured at predetermined time intervals, starting at
the beginning of the periodic reaction.
<Data Processing>
[0067] The computer 33 obtains an interferogram (temporally changed
interference light data) formed of the intensity data corresponding
to the stop positions (P.sub.1, P.sub.2, . . . , and P.sub.n) of
the moving mirror 27 for each minute measurement region according
to the intensity data obtained at each stop position of the moving
mirror 27 at each sampling time.
[0068] More specifically, the computer 33 obtains an interferogram
(temporally changed interference light data) 56a formed of the
intensity data (I.sub.a1, I.sub.a2, . . . , and I.sub.an)
corresponding to the stop positions (P.sub.1, P.sub.2, . . . , and
P.sub.n) of the moving mirror 27 for the minute measurement region
54a, as shown in FIG. 3C. The computer 33 obtains an interferogram
(temporally changed interference light data) 56b formed of the
intensity data (I.sub.b1, I.sub.b2, . . . , and I.sub.bn)
corresponding to the stop positions (P.sub.1, P.sub.2, . . . , and
P.sub.n) of the moving mirror 27 for the minute measurement region
54b, as shown in FIG. 3C. The computer 33 obtains an interferogram
(temporally changed interference light data) 56c formed of the
intensity data (I.sub.c1, I.sub.c2, . . . , and I.sub.cn)
corresponding to the stop positions (P.sub.1, P.sub.2, . . . , and
P.sub.n) of the moving mirror 27 for the minute measurement region
54c, as shown in FIG. 3C.
[0069] In the present embodiment, when intensity data each having a
predetermined time delay from the periodic reaction have been
sampled a predetermined number of times at a certain stop position
of the moving mirror 27, the moving mirror 27 is moved to the next
stop position, and intensity data having a time delay corresponding
to the next stop position is sampled in the same way. Sampling is
performed with a time delay corresponding to each stop position,
and measurement is conducted a target number of times. An
interferogram formed of intensity data with each time delay is
obtained for each minute measurement region.
[0070] Then, the computer 33 obtains time-resolved spectrum data
according to each interferogram, as shown in FIG. 3C.
[0071] Specifically, the computer 33 applies a Fourier transform to
the interferogram data 56a corresponding to the minute measurement
region 54a to obtain time-resolved spectrum data 58a. The computer
33 applies a Fourier transform to the interferogram data 56b
corresponding to the minute measurement region 54b to obtain
time-resolved spectrum data 58b. The computer 33 applies a Fourier
transform to the interferogram data 56c corresponding to the minute
measurement region 54c to obtain time-resolved spectrum data
58c.
[0072] Microscopic measurement of temporal changes is performed in
the present embodiment with the use of the infrared microscope
having the multi-element infrared detector 14, and the Fourier
transform infrared spectrophotometer 16 capable of step scanning.
As a result, a surface distribution can be obtained in
time-resolved measurement of microsecond-order for periodic
reactions.
[0073] In the present embodiment, to maintain reproducibility of
the start of the periodic reaction, it is preferred that an
excitation light source, such as a unit emitting short pulses, be
used. To perform successful sampling, it is also preferred in the
present embodiment that a delay unit capable of specifying a time
delay for a sampling time according to each stop position of the
moving mirror 27 be provided.
<Measurement-Area Moving Unit>
[0074] It is also important in the above-described structure that
the measurement area can be moved in order to obtain a surface
distribution over a wider area of a sample. For this purpose, the
stage 42, the stage driver 44, and the stage controller 46 serve as
a measurement-area moving unit.
[0075] When measurement has been finished at a certain measurement
area, the measurement-area moving unit moves the sample so that
measurement can be performed at the next measurement area. Then,
time-resolved measurement is performed at the next measurement area
in the same way. Time-resolved measurement at each measurement area
and changing the movement area by the measurement-area moving unit
are repeated until time-resolved measurement is finished for all
target areas.
<Selection of Multi-Element Detector>
[0076] In the above-described embodiment, a multi-element detector
in which the photoelectric elements are disposed in one dimension
is used. This is because such a structure is advantageous in that
intensity data from each photoelectric element can be concurrently
sampled at a higher speed. A multi-element detector in which all
photoelectric elements are disposed two dimensionally can be used
instead.
[0077] Although a multi-element detector having photoelectric
elements disposed in one dimension is slightly affected by light
coming from adjacent measurement regions, it can concurrently
measure a smaller number of measurement regions than a
multi-element detector having photoelectric elements disposed two
dimensionally. Since highly precise measurement is especially
important in the above-described embodiment compared with a
reduction in measurement time, it is preferred that a multi-element
detector having photoelectric elements disposed in one dimension be
used.
[0078] A multi-element detector having photoelectric elements
disposed two dimensionally can concurrently measure a larger number
of measurement regions than a multi-element detector having
photoelectric elements disposed in one dimension, but it is
significantly affected by light coming from adjacent measurement
regions. When a reduction in measurement time is especially
important in the above-described embodiment compared with highly
precise measurement, a multi-element detector having photoelectric
elements disposed two dimensionally can be used.
Effectiveness
[0079] As described above, the microscope of the present invention
includes the multi-element detector, the Fourier transform
spectrophotometer serving as the spectroscope, and the data sampler
for concurrently sampling intensity data from each photoelectric
element of the multi-element detector at timing determined by the
spectrophotometer. As a result, the time-resolved spectrum is
obtained in the present invention.
[0080] In combination with the measurement-area moving unit,
sample-surface analysis can be performed at a high speed in the
present invention.
* * * * *