JP3681608B2 - Spectroscopic sectional image measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spectroscopic cross-sectional image measuring apparatus that performs spectroscopic measurement by performing spectroscopic measurement simultaneously with a tomographic image.
[0002]
[Prior art]
Conventionally, spectral information has not been obtained for a cross-sectional image in a cross-sectional image measuring apparatus. Some reports have obtained spectral information through signal processing, but there is a problem in reliability due to signal processing rather than direct measurement.
[0003]
[Problems to be solved by the invention]
Spectral information that has not been obtained in conventional cross-sectional image measurement can be added to a tomographic image through highly reliable direct measurement, which means that the activity state can be measured, including metabolism in the living body, which is important in the biochemical field. is there.
[0004]
In view of the above situation, an object of the present invention is to provide an accurate and highly reliable spectroscopic cross-sectional image measurement apparatus that can obtain tomographic structure information and spectral information in an image thereof.
[0005]
[Means for Invention]
In order to achieve the above object, the present invention provides
[1] In a spectroscopic sectional image measurement apparatus, a broadband wavelength light source, an optical fiber connected to the broadband wavelength light source, a collimator lens connected to the optical fiber, and a beam disposed behind the collimator lens A splitter, a spatial division type phase modulator that receives a part of the light wave from the beam splitter, a high voltage signal generator connected to the spatial division type phase modulator, and behind the spatial division type phase modulator A half mirror to be disposed; a collimator lens disposed behind the half mirror to irradiate a biological sample with signal light; a condenser lens that receives output light from the beam splitter; and a first lens connected to the condenser lens. A first optical fiber, a second optical fiber, a multi-channel spectrometer connected to the first optical fiber, and a second optical fiber. And a multi-channel spectroscope and a computer for image data processing that captures an output signal from the photo-detector, measure a tomographic image from the biological sample, and from the multi-channel spectroscope The wavelength spectrum of scattered light is also measured simultaneously.
[0006]
[2] In the spectroscopic cross-sectional image measuring apparatus according to [1], the broadband wavelength light source is created using a periodic domain inversion crystal in which a crystal axis of a nonlinear optical crystal is periodically inverted. .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0008]
FIG. 1 is an overall configuration diagram of a spectroscopic cross-sectional image measuring apparatus showing an embodiment of the present invention.
[0009]
In this figure, 1 is a broadband wavelength light source, 2 is an optical fiber connected to the broadband wavelength light source 1, 3 is a collimator lens connected to the optical fiber 2, 4 is a beam splitter, and 5 is a light wave from the beam splitter 4. Is a high voltage signal generator connected to the spatial division type phase modulator 5, 7 is a half mirror, 8 is a collimator lens (objective lens), and 9 is a biological sample. 10 is a condensing lens, 11 is a first optical fiber, 12 is a multichannel spectroscope connected to the first optical fiber 11, 13 is a second optical fiber, and 14 is a second optical fiber 13. A photo detector 15 is connected to a multi-channel spectroscope 12 and a photo detector 14 which captures output signals from the photo detector 14.
[0010]
As shown in FIG. 1, the spectroscopic cross-sectional image measuring apparatus of this embodiment is a space that receives a part of a light wave from a broadband wavelength light source 1, an irradiation optical system (2, 3, 4), and a beam splitter 4. Split type phase modulator 5 , high voltage signal generator 6 connected to the spatial split type phase modulator 5 , half mirror 7 , collimator lens (objective lens) 8 , biological sample 9 , condenser lens 10 , first An optical fiber 11 , a multi-channel spectroscope 12 connected to the first optical fiber 11, a second optical fiber 13 , a photodetector 14 connected to the second optical fiber 13, and an image data processing computer 15.
[0011]
Therefore, the broadband wavelength light source 1, the irradiation optical system (2, 3, 4), the spatial division type phase modulator 5 , the high voltage signal generator 6, the half mirror 7 , the collimator lens (objective lens) 8 , the biological sample 9 , A tomographic image is measured based on the conventional OCT principle with the optical lens 10 , the first optical fiber 11 , the second optical fiber 13 , and the photodetector 14, but a multichannel spectrometer 12 (high-speed spectrometer) is used. Thus, the wavelength spectrum of the scattered light is also measured simultaneously.
[0012]
Here, a broadband light source will be described.
[0013]
At present, it has been demonstrated that wavelength conversion can be realized with high efficiency by using a periodic domain inversion crystal in which the crystal axis of a nonlinear optical crystal is periodically inverted, but it can only be applied to a coherent light source (narrow spectral width). is there. Therefore, here, this is extended to an incoherent light source and used to create a broadband wavelength light source effective for tomographic image measurement.
[0014]
First, as a first example, as shown in FIG. 2A, a light wave of a coherent light source λ ₀ (see FIG. 2B) is incident on the periodic domain inversion nonlinear optical crystal 16 and has a plurality of periods. continuous or discontinuous wavelength lambda ₁ to [lambda] ₂ can be obtained [FIG. 2 (c) refer to Fig. In the above-described periodic domain inversion nonlinear optical crystal 16, the period of inversion can be freely changed, so that the spectrum of the generated light can be realized freely. That is, an ideal light source for tomographic image measurement can be realized.
[0015]
Further, as a first example, as shown in FIG. 2D, excitation light (continuous or pulsed) is incident on a resonator 18 having a broadband reflection mirror 17, and continuous or discontinuous wavelengths λ _{1 to} λ ₂ [See FIG. 2 (c)].
[0016]
Next, a description will be given of the light wave incident on the two-dimensional array photodetector and its processing.
[0017]
FIG. 3 is an explanatory diagram of the entire system, FIG. 4 is a perspective view of a two-dimensional array-type photodetector, and FIG. 5 is a diagram showing light waves in a cross section at cd of the two-dimensional array-type photodetector. is there.
[0018]
In FIG. 3, 21 is a low coherence light source, 22 is a lens, 23 is a slit, 24 is a beam splitter (BS), 25 is an objective lens, 26 is a biological sample, 27 is a lens, 28 is a vibrating mirror, and 29 is a piezo device ( PZT), 30 is a high-voltage amplifier, 31 is an oscillator, 32 is a lens, and F is a focal length.
[0019]
In FIG. 3, the light wave R is shifted with respect to the light wave S by the vibration mirror 28 vibrating at the frequency f. That is, when the biological sample 26 has the high scattering points a and b on the plane P1, the backscattered light from the plane P1 forms an image on the plane P2 of the two-dimensional array-shaped photodetector 1, but the intensity is high. It changes with time at the frequency f.
[0020]
Next, the light wave S and the light wave R are combined by the beam splitter 24 and imaged by the lens 32, whereby a light intensity distribution that changes with time on the plane P2 of the two-dimensional array-shaped photodetector 1 is obtained. Arise. This state is shown in FIGS. In other words, the light intensity a ′, b ′ changes with the frequency f in time in the cross section taken along line cd of the two-dimensional arrayed photodetector 1.
[0021]
FIG. 6 is a schematic diagram of a two-dimensional optical heterodyne scanning detection system, and FIG. 7 is a diagram showing signal intensities at respective portions.
[0022]
As shown in these drawings, the two-dimensional arrayed photodetector 1 is sequentially switched by the scanning unit from i = 1 to N in the switching time of time T ₀ , and finally outputted from the terminal c. That is, the external output terminal a [light intensity] of the two-dimensional array photodetector 1 has a signal intensity as shown in FIG. Here, _CAC represents an AC component, and _CDC represents a DC component. Further, the output terminal b [after detection] of the first-stage detection circuit unit 3A has a signal strength as shown in FIG. 7B, and the output terminal c [band-pass filter of the second-stage detection circuit unit 3B]. After pass] shows the signal intensity as shown in FIG. That is, in FIG. 7C, the signal intensity corresponding to the amplitude of the beat signal is output as a pixel signal.
[0023]
FIG. 8 is a schematic diagram of a heterodyne light detection system.
[0024]
In this figure, 41 is a light source, 42 is an optical fiber, 43 is a lens, 44 is a beam splitter, 45 is a collimator lens, 46 is a biological sample, 47 is a light modulator, 48 is a high voltage amplifier, 49 is an oscillator, and 50 is a lens. , 51 are optical fibers, and 52 is a photodetector.
[0025]
According to the principle described separately, when the optical paths of the light wave S and the light wave R are equal within the coherence length, the heterodyne beat signal is measured from the photodetector 52, and the intensity of the post-scattered light from the scattering point 46A is measured. Become. Therefore, in this case, if the biological sample 46 is scanned in the x direction, the profile in the depth direction is measured, and if the biological sample 46 is scanned in the y direction, the profile in the lateral direction is measured.
[0026]
As a result, the x- and y-plane tomographic images can be measured by repeating x-direction scanning → y-direction 1-step scanning → x-direction scanning → y-direction 1-step scanning.
[0027]
FIG. 9 is a block diagram of the spectroscopic cross-sectional image measuring apparatus of the present invention.
[0028]
In this figure, 61 is a light source, 62 is a lens, 63 is a beam splitter BS, 64 is a half mirror, 65 is a collimator lens, 66 is a biological sample, 67 is a spatial division phase modulator, 68 is a condensing lens, and 69 is A second optical fiber, 71 is a first optical fiber, 70 is a photodetector, 72 is a multichannel spectroscope, and 73 is a computer for image data processing.
[0029]
FIG. 10 is a block diagram of a multichannel spectrometer according to the present invention.
[0030]
In this figure, 81 is a spectroscope body, 82 is a slit formed in the spectroscope body 81 , 83 is a concave mirror M1, 84 is a diffraction grating, and the diffraction grating 84 has an emission angle different depending on the wavelength. 85 is a concave mirror M2, 86 is a photodiode array, 87 is a multichannel detector, and 88 is a lens.
[0031]
The multiwavelength light wave obtained through the first optical fiber 71 (see FIG. 9) is taken into the spectroscope body 81 from the slit 82 through the lens 88, and passes through the concave mirror 83, the diffraction grating 84, and the concave mirror 85, and the photodiode array. A multi-channel detector 87 having 86 is used for detection. Here, the multi-channel spectrometer 72 has a multi-channel detector 87 such as a photodiode array arranged at the position of the exit slit of the original spectrometer. Thereby, spectral information can be measured instantaneously without mechanically rotating the diffraction grating of the old type.
[0032]
Therefore, in measurement A, as shown in FIG. 11A, the intensity of scattered light from point a in the biological sample 66 is measured. In the measurement B, as shown in FIG. 11B, the spectrum of the scattered light from the point a of the biological sample 66 can be measured. In the spectrum measurement, specific wavelengths λ ₁ , λ ₂ , λ ₃ , λ Measurement for ₄ and continuous spectrum measurement of λ _{1 to} λ ₂ are also possible.
[0033]
Such information is processed by the computer 73 (see FIG. 9).
[0034]
Since it comprised in this way, since the tomographic structure information and the spectrum information in the image can be obtained, a new medical application is expected.
[0035]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.
[0036]
【The invention's effect】
As described above in detail, according to the present invention, the following effects can be obtained.
[0037]
Spectral information that has not been obtained in the past when measuring a tomographic image is added to the tomographic image by a reliable direct measurement, and the activity state can be measured including the metabolism of the living body. The practical effects in the chemical field are significant.
[0038]
In other words, in addition to tomographic images, spectral information can also be measured, so new biochemical knowledge can be obtained. In the medical field, it is expected to be applied to new clinical diagnosis and basic research, and further to semiconductor and other industrial fields. A wide range of applications are expected and its ripple effect is enormous.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a spectroscopic cross-sectional image measuring apparatus showing an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a broadband wavelength light source showing an embodiment of the present invention.
FIG. 3 is an explanatory diagram of a two-dimensional optical heterodyne system.
FIG. 4 is a perspective view of a two-dimensional array photodetector showing an embodiment of the present invention.
5 is a diagram showing light waves in a cross section taken along line cd of the arrayed photodetector in FIG. 4; FIG.
FIG. 6 is a schematic diagram of a two-dimensional optical heterodyne scanning detection system showing an embodiment of the present invention.
7 is a diagram showing signal intensities at various parts in FIG. 6;
FIG. 8 is a schematic diagram of a heterodyne light detection system.
FIG. 9 is a configuration diagram of a spectroscopic cross-sectional image measuring apparatus according to the present invention.
FIG. 10 is a configuration diagram of a multichannel spectrometer according to the present invention.
FIG. 11 is a diagram showing the output and spectral information of the photodetector according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Broadband wavelength light source 2,42,51, Optical fiber 3,8,45,65 Collimator lens 4,24,44,63 Beam splitter 5,67 Spatial division type phase modulator 6 High voltage signal generator 7,64 Half mirror 9, 26, 46, 66 Biological sample 10, 68 Condensing lens 11, 71 First optical fiber 12, 72 Multichannel spectrometer 13, 69 Second optical fiber 14, 52, 70 Photo detector 15, 73 Image Data processing computer 16 Periodic domain inversion nonlinear optical crystal 17 Broadband reflection mirror 18 Resonator 21 Low coherence light source 22, 27, 32, 43, 50, 62, 88 Lens 23, 82 Slit 25 Objective lens 28 Vibrating mirror 29 Piezo device ( PZT)
30, 48 High-voltage amplifier 31, 49 Oscillator 41, 61 Light source 46A Scattering point 47 Optical modulator 81 Spectrometer main body 83 Concave mirror M1
84 Diffraction grating 85 Concave mirror M2
86 Photodiode array 87 Multichannel detector

Claims (2)

(A) a broadband wavelength light source;
(B) an optical fiber connected to the broadband wavelength light source;
(C) a collimator lens connected to the optical fiber;
(D) a beam splitter disposed behind the collimator lens;
(E) a space division type phase modulator that receives a part of the light wave from the beam splitter;
(F) a high voltage signal generator connected to the spatial division phase modulator;
(G) a half mirror disposed behind the spatial division phase modulator;
(H) a collimator lens disposed behind the half mirror and irradiating a biological sample with signal light;
(I) a condenser lens that receives the output light of the beam splitter;
(J) a first optical fiber and a second optical fiber connected to the condenser lens;
(K) a multichannel spectrometer connected to the first optical fiber;
(L) a photodetector connected to the second optical fiber;
(M) an image data processing computer for capturing an output signal from the multi-channel spectroscope and a photodetector;
(N) A spectroscopic cross-sectional image measuring apparatus that measures a tomographic image from the biological sample and simultaneously measures a wavelength spectrum of scattered light from the multichannel spectrometer.   2. The spectroscopic cross-section image measuring apparatus according to claim 1, wherein the broadband wavelength light source is created by using a periodic domain inversion crystal in which a crystal axis of a nonlinear optical crystal is periodically inverted. Image measuring device.

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