WO2014126401A1

WO2014126401A1 - Optical interference tomographic method and apparatus

Info

Publication number: WO2014126401A1
Application number: PCT/KR2014/001194
Authority: WO
Inventors: 정지채; 김지현
Original assignee: 고려대학교 산학협력단
Priority date: 2013-02-13
Filing date: 2014-02-13
Publication date: 2014-08-21
Also published as: KR101438748B1; KR20140102034A

Abstract

The optical interference tomographic method includes the steps of: dividing the light output of a light source into a first and a second optical signal; irradiating a measured object with the first optical signal, and a reference mirror with the second optical signal; feeding back the measurement optical signal obtained from the first optical signal reflected by the measured object and the reference optical signal obtained from the second optical signal reflected by the reference mirror; combining the measurement optical signal and the reference optical signal; and measuring the intensity of an interference signal based on the combination of the measurement and the reference optical signal, wherein the second optical signal is irradiated on the reference mirror by applying the incident angle and the reflection angle of the second optical signal set based on the intensity of the interference signal previously measured.

Description

Optical coherence tomography apparatus and method

The present invention relates to an optical coherence tomography apparatus and method.

Optical coherence tomography (hereinafter referred to as 'OCT') is a device that photographs the inside of a living tissue and material in high resolution using light that is harmless to the human body. Such OCT can take a high-resolution image of monolayers of minute portions in biological tissues and materials using sub-wavelength interference light sources, to sub-micron regions.

OCT is widely used in laser tomography, optical fiber sensor systems, or optical communication in medical imaging, and can be classified into frequency domain OCT and spectrum domain OCT according to principles and structures.

The spectral region OCT uses a broadband light source, and the broadband light source analyzes the image of the light reflected from the measuring object for each wavelength band by a spectrometer. As such a spectrometer, a line detector in the form of a CMOS (Complementary Oxide Semiconductor) camera or a Charge-Coupled Device (CCD) camera is used. In general, spectrometers are designed so that a specific wavelength of a broadband light source is mapped to a specific pixel of a CCD or CMOS camera, and the mapped wavelength-specific pixels are kept linear. The spectral region OCT obtains depth information of a measurement object by Fourier transforming a pixel combination.

On the other hand, the OCT is an apparatus for obtaining an image by analyzing the interference pattern generated by the optical path difference between the reference signal and the sample signal (measurement signal), it is necessary to adjust the reference signal according to the situation.

Conventional OCT uses a method of reducing the size of light by mounting a ND (Neutral density) filter in the reference signal stage to obtain an appropriate reference signal. However, because the light attenuation of the ND filter is fixed, it is difficult to accurately obtain a desired level of reference signal. In order to solve this problem, a method of using a variable ND filter in which the amount of light attenuation of the ND filter is gradually changed is proposed. However, since the reference signal acquisition method using the ND filter changes the light intensity by moving the ND filter itself, it has a disadvantage in that it depends on the blocking coefficient of each wavelength of light of the ND filter, is slow, and the volume of the OCT is large.

In this regard, Korean Patent No. 849193 (Occurity System of the Invention) installs a filter member on an optical path between a light source and a detector so as to process an image by allowing the light to leave a time difference for each spectrum, Using a filter member such as a Fabry-Perot filter to disclose a configuration for processing the image by advancing by the wavelength with a time difference before the light generated from the light source is split in the light splitter or reflected from the measurement skin and combined in the light splitter have.

The present invention is to solve the above-mentioned problems of the prior art, to provide an optical coherence tomography apparatus and method in which a reference signal stage capable of adjusting the reference light amount is implemented.

However, the technical problem to be achieved by the present embodiment is not limited to the technical problem as described above, and other technical problems may exist.

The optical interference tomography apparatus according to an aspect of the present invention for achieving the above technical problem, the light source for outputting light, the light output from the light source is divided into a first optical signal and a second optical signal and output And an interferometer for feedback receiving and combining the measurement light signal corresponding to the first optical signal and the reference light signal corresponding to the second optical signal, and irradiating the measurement target with the first optical signal output through the interferometer. An object measuring unit for feeding back the measurement light signal reflected from the measurement object to the interferometer, irradiating the second optical signal output through the interferometer to a reference mirror, and applying the reference light signal reflected from the reference mirror to the interferometer A reference light generator for feeding back, measuring the interference signal strength of the measurement light signal and the reference light signal coupled through the interferometer And a reference light amount adjusting unit for controlling the incident angle of the second optical signal to the reference mirror or the reflection angle of the reference mirror to be changed based on the photodetector and the previously measured interference signal strength.

In accordance with another aspect of the present invention, an optical coherence tomography method using an optical coherence tomography apparatus comprises: (a) dividing and outputting light output from a light source into a first optical signal and a second optical signal, and (b) the Irradiating a first optical signal to a measurement object and irradiating the second optical signal to a reference mirror, (c) a measurement light signal in which the first optical signal is reflected from the measurement object, and the second optical signal is the reference mirror Receiving feedback of the reference light signal reflected from each other, (d) combining the fed back measurement light signal and reference light signal, and (e) measuring interference signal strength based on the combined measurement light signal and reference light signal Wherein the step (b) includes the incident angle of the second optical signal into the reference mirror or the reflection angle from the reference mirror set based on the interference signal strength previously measured. Apply the second optical signal.

According to any one of the problem solving means of the present invention described above, by adjusting the amount of light of the reference light signal tomography, the sensitivity of the tomography image can be improved to provide a clear tomography image.

In addition, according to any one of the problem solving means of the present invention, it is possible to implement the reference light signal stage without a separate filter member can reduce the volume of the optical coherence tomography apparatus, and optimize the reference light signal irrespective of the blocking coefficient for each light wavelength can do.

Further, according to any one of the problem solving means of the present invention, by using the interference signal strength detected in real time, by actively changing the intensity of the next reference light signal, it is possible to quickly process the optimal tomography for the measurement object. .

1 is a block diagram showing the configuration of an optical coherence tomography apparatus according to an embodiment of the present invention.

2 is a block diagram showing the configuration of the reference light amount adjusting unit according to an embodiment of the present invention.

3 is a block diagram showing the configuration of the reference light amount adjusting unit according to another embodiment of the present invention.

4 is a block diagram showing the configuration of the reference light amount adjusting unit according to another embodiment of the present invention.

5 is an example showing the spectrum of the interference signal strength according to the reference light amount control in an embodiment of the present invention.

6 is an example showing a normalized light amount map for a reference light signal according to an embodiment of the present invention.

7 is an example of a tomography image for explaining an effect of adjusting the amount of light of a reference light signal according to an embodiment of the present invention.

8 is a flowchart illustrating a method for optical coherence tomography according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a configuration diagram showing the configuration of an optical coherence tomography apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the optical coherence tomography apparatus 100 includes a light source 110, an interferometer 120, an object measuring unit 130, a reference light generating unit 140, a reference mirror 150, and a photodetector ( 160, a reference light amount adjusting unit 170, and a tomography image processing unit 180.

The light source 110 outputs light for optical coherence tomography to the interferometer 120.

The interferometer 120 splits the light output from the light source 110 into a first optical signal and a second optical signal. The interferometer 120 outputs the first optical signal toward the measurement object through the target measurement unit 130, and outputs the second optical signal toward the reference mirror 150 through the reference light generator 140.

The interferometer 120 receives feedback of the measurement light signal corresponding to the first optical signal through the target measurement unit 130, and feedbacks the reference light signal corresponding to the second optical signal through the reference light generator 140.

The interferometer 120 combines the feedback light signal and the reference light signal and transmits the measured light signal to the photodetector 160.

The object measuring unit 130 irradiates the measurement object with the first optical signal output through the interferometer 120, and feeds back the measurement light signal reflected from the measurement object to the interferometer 120.

The target measuring unit 130 may include a first optical collimator (not shown) that collects the first optical signal output from the interferometer 120 and outputs the parallel optical light toward the measurement object. The first optical collimator (not shown) may be configured as a scanning lens.

The reference light generator 140 radiates the second optical signal output through the interferometer 120 to the reference mirror 150, and feeds back the reference light signal reflected from the reference mirror 150 to the interferometer 120.

The reference light generator 140 may include a second optical collimator (not shown) that collects the second optical signal output from the interferometer 120 and outputs the parallel light toward the reference mirror 150. The second optical collimator (not shown) may be configured as a focusing lens. For example, by configuring each lens of the first optical collimator and the second optical collimator as the same lens, tomography images can be easily obtained without separately matching the refractive indices between the reference light signal stage and the target measurement stage.

The photodetector 160 measures the interference signal strength of the measurement light signal and the reference light signal coupled through the interferometer 120, and measures the measured interference signal strength with the tomographic image processor 180 and the reference light amount controller 170. send.

The tomography image processor 180 processes and processes the value of the interference signal strength measured by the photodetector 160 in a preset manner to generate and provide a tomography image of the measurement object.

In detail, the tomography image processor 180 extracts depth information according to the interference signal intensity value of the measurement object scanned by the target measurement unit 130, and collects a predetermined number of depth information for each pixel to obtain a tomography image. Configure. The tomography image processing unit 180 extracts depth information by performing inverse Fourier transform after performing equal-space k-spatial conversion of the values of the interference signal strengths acquired through the photodetector 160 with respect to a predetermined wavelength.

On the other hand, the optical interference tomography apparatus 100 according to the embodiment of the present invention adjusts the magnitude of the reference light signal fed back through the reference light generator 140, and thus the signal-to-noise ratio of the tomography image. ) And improve the sensitivity.

In detail, the photodetector 160 includes a photographing means (eg, a camera) including an optical sensor. If the amount of light of the measurement light signal and the reference light signal received by the photodetector 160 through the interferometer 120 is too strong, the light sensor of the photodetector 160 is in a state of light saturation (that is, the interference signal Strength) can be difficult to measure. In addition, when the amount of light of the measurement light signal and the reference light signal received by the photodetector 160 is too weak, the signal-to-noise ratio and the sensitivity of the interference signal may be reduced, resulting in deterioration of the tomography image.

Accordingly, the reference light amount adjusting unit 170 is based on the previously measured interference signal strength (hereinafter referred to as 'previous interference signal strength') of the incident angle of the second optical signal to the reference mirror 150 or the reference mirror 150 Control the reflection angle with respect to the second optical signal.

In detail, the reference light amount adjusting unit 170 determines the target intensity of the reference light signal based on the photosaturation threshold of the photodetector 160 and the previous interference signal strength received from the photodetector 160. The reference light amount adjusting unit 170 changes the incident angle of the second optical signal to the reference mirror 150 or the reflection angle of the reference mirror 150 with respect to the second optical signal based on the determined target intensity of the reference light signal.

In this case, the reference light amount adjusting unit 170 may set the initial value of the interference signal strength according to the measurement light signal and the reference light signal first fed back to the interferometer 120 with respect to the measurement object as the previous interference signal strength.

That is, before the optical interference tomography apparatus 100 measures the effective interference signal intensity for generating the tomographic image of the measurement object, the optical interference tomography apparatus 100 first performs a test step of determining the optimal reference light signal strength for the photodetector 150. To perform. Accordingly, in the state where the incident angle of the second optical signal set based on the optimal reference light signal intensity (that is, the target intensity) to the reference mirror 150 or the reflection angle of the reference mirror 150 with respect to the second optical signal is applied, A reference light signal can be obtained.

Hereinafter, various embodiments of the reference light amount adjusting unit 170 according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4.

First, Figure 2 is a block diagram showing the configuration of the reference light amount adjusting unit according to an embodiment of the present invention.

As shown in FIG. 2, the reference light amount adjusting unit 170 includes the

optical systems

171 and 172 and the optical system driver 173.

In detail, the

optical systems

171 and 172 reflect the second optical signal output through the reference light generator 140 toward the reference mirror 150 at a predetermined reflection angle, respectively, to adjust the incident angle to the reference mirror 150.

In FIG. 2, the reference light amount adjusting unit 170 is reflected from the first optical system 171 and the first optical system for reflecting the second optical signal output in the first travel direction in a second travel direction different from the first travel direction. It includes a second optical system 172 for reflecting the optical signal in the first travel direction to enter the reference mirror 150. Such a plurality of optical systems are opposed to each other so that light reflected from any one of the other optical systems is incident.

In FIG. 2, the reference light amount adjusting unit 170 includes two

optical systems

171 and 172, but the reference light amount adjusting unit 170 may include one or more optical systems.

The optical system driver 173 sets the reflection angle for each optical system based on the plurality of

optical systems

171 and 172 and the previous interference signal strength, and rotates the optical system driver 173 based on the reflection angle for each optical system.

In this case, as described above, the optical system driver 173 determines the target intensity of the reference light signal based on the previous interference signal strength, and sets the reflection angles of the first and second

optical systems

171 and 172 according to the target intensity of the reference light signal. do.

As shown in FIG. 3, the reference light amount adjusting unit 170 includes an optical collimator driver 174 that controls the second optical signal output angle of the reference light generating unit 140.

Specifically, the optical collimator driver 174 sets the optical output angle of the reference light generator 140 (that is, the optical output angle of the second optical collimator (not shown)) based on the previous interference signal strength, and sets the set optical output. Based on the angle, the second optical collimator (not shown) is rotated in a set direction and angle.

In this case, the optical collimator driver 174 determines the target intensity of the reference light signal based on the previous interference signal strength as described above, and sets the optical output angle of the second optical collimator (not shown) according to the target intensity of the reference light signal. do.

As shown in FIG. 4, the reference light amount adjusting unit 170 according to another embodiment of the present invention includes a reference mirror driving unit 175.

In detail, the reference mirror driver 175 sets the reflection angle of the reference mirror 150 based on the previous interference signal strength, and rotates the reference mirror 150 in the set direction and angle based on the set reflection angle.

In this case, as described above, the reference mirror driver 175 determines the target intensity of the reference light signal based on the previous interference signal strength, and sets the reflection angle of the reference mirror 150 according to the target intensity of the reference light signal.

As such, the reference light amount adjusting unit 170 is fed back through the reference light generating unit 140 by adjusting the incident angle of the second optical signal incident on the reference mirror 150 or the reflection angle of the second optical signal of the reference mirror 150. The amount of light of the reference light signal is changed.

For example, FIG. 5 is an example showing the spectrum of the interference signal strength according to the reference light amount control in the embodiment of the present invention.

In FIG. 5, the light quantity spectrum of the interference signal acquired by the photodetector 160 according to the change in the light amount of the reference light signal is shown, and it can be seen that the interference signal intensity is different as the light amount of the reference light signal is changed.

On the other hand, in the optical interference tomography apparatus 100 according to the exemplary embodiment of the present invention, the reference light amount adjusting unit 170 is applied to the incident angle of the second optical signal to the reference mirror 150 or to the second optical signal of the reference mirror 150. A reference generation unit (not shown) may be further provided to provide setting criteria to accurately and quickly determine the angle of reflection for the target.

Specifically, the reference generator (not shown) matches the reference light by matching at least one of the incident angle of the second optical signal to the reference mirror 150 and the reflection angle of the reference mirror 150 with respect to the second optical signal for each reference light signal intensity. Generate and store a normalized light quantity map for the signal.

For example, FIG. 6 is an example showing a normalized light amount map for a reference light signal according to an embodiment of the present invention.

In the normalized light quantity map shown in FIG. 6, the amount of light reflected by the position of the reference mirror according to any one of the reflection angle of the plurality of optical systems, the output angle of the second optical collimator, and the reflection angle of the reference mirror described above with reference to FIGS. It is a light quantity distribution map which shows.

For reference, the reference light amount adjusting unit 170 may detect the incident angle or the reflection angle matching the target intensity of the reference light signal from the normalized light amount map generated and stored by the reference generator (not shown).

Such a reference generation unit (not shown) may be included in the optical interference tomography apparatus 100 described above with reference to FIG. 1 as a configuration, and the reference light amount adjusting unit 170 is a self-contained reference generation unit (not shown). It is also possible to perform the operation.

As described above, the optical coherence tomography apparatus 100 according to the exemplary embodiment of the present invention actively changes and changes the intensity of the reference light signal by using the interference signal intensity detected in real time, thereby providing optimal tomography for the measurement object. Can be processed quickly.

For example, FIG. 7 is an example of a tomography image for explaining a light amount control effect of a reference light signal according to an embodiment of the present invention.

FIG. 7A is a tomography image of a measurement object without adjusting the amount of light of the reference light signal, and FIG. 7B shows an object to be measured by applying an optimal amount of light of the reference light signal set according to the interference signal strength measured in advance. It is a tomography image taken.

As such, when tomography is performed by adjusting the amount of light of the reference light signal through the optical interference tomography apparatus 100, the sensitivity of the tomography image may be improved to provide a clear tomography image.

Hereinafter, the optical coherence tomography method will be described in detail with reference to FIG. 8.

8 is a flowchart illustrating a method for optical coherence tomography according to an embodiment of the present invention.

First, the target intensity of the reference light signal suitable for the light saturation threshold value of the photodetector of the optical interference tomography apparatus is determined (S110).

Specifically, prior to acquiring the next measurement light signal and the reference light signal in the tomography of the measurement object, the reference light signal based on the previous interference signal intensity and the light saturation threshold measured based on the previous measurement light signal and the reference light signal. To determine the target strength.

For example, the light saturation threshold may be set to the light saturation of the light sensor in the photodetector, and assuming that the light saturation of the light sensor is 100%, the target intensity of the reference light signal is 90% or less of the light saturation. Can be set.

For reference, the previous interference signal strength may be an initial value of the interference signal strength according to the measurement light signal and the reference light signal first fed back to the measurement object.

Then, the incident angle of light with respect to the reference mirror of the optical interference tomography apparatus or the light reflection angle of the reference mirror is set and applied based on the determined target intensity of the reference light signal (S120).

For example, the angle of incidence of the light with respect to the reference mirror may be changed by controlling the driving of a plurality of optical systems positioned between the interferometer and the reference mirror of the optical coherence tomography apparatus and changing the traveling path and angle of the light output through the interferometer. In addition, the incident angle of the light to the reference mirror may be changed by controlling the driving of the optical collimator for outputting the light output through the interferometer at a set output angle. In addition, the reflection angle of the reference mirror may be changed by controlling the driving of the reference mirror itself.

On the other hand, prior to the step (S110) or (S120), the normalized light amount map for the reference light signal to generate a normalized light amount map for the reference light signal by matching the incident angle of the optical signal to the reference mirror or the reflection angle for the optical signal of the reference mirror in advance for each reference light signal intensity Can be. In this case, the incident angle or the reflection angle matched to the target intensity of the reference light signal may be quickly detected using the normalized light amount map in step S120.

Then, the light output from the light source is divided into a first optical signal and a second optical signal through an interferometer and outputs (S130).

Then, the target measuring unit of the optical coherence tomography apparatus irradiates the first optical signal to the measurement object, and the reference light generating unit irradiates the second optical signal to the reference mirror (S140).

At this time, the second optical signal is irradiated to the reference mirror in a state in which the incident angle of light with respect to the reference mirror or the light reflection angle of the reference mirror is applied in step S120.

Next, the interferometer receives feedback of the measurement light signal reflected from the measurement object through the target measurement unit, and receives the reference light signal reflected from the reference mirror through the reference light generator (S150).

Then, the interference signal intensity based on the measured light signal and the reference light signal is measured through the photodetector of the optical coherence tomography apparatus (S160).

Thereafter, a tomography image of the measurement object is generated and provided based on the measured interference signal strength (S170).

On the other hand, in the optical coherence tomography method according to an embodiment of the present invention, the step (S110) of determining the target intensity of the reference light signal is applied to the initial value of the interference signal intensity once or based on the previous interference signal every tomography. It is possible to apply.

Embodiments of the present invention may also be implemented in the form of a recording medium containing instructions executable by a computer, such as a program module executed by the computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, computer readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transmission mechanism, and includes any information delivery media.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

As shown in FIG. 2, the reference light amount adjusting unit 170 includes the

optical systems

171 and 172 and the optical system driver 173.

In detail, the

optical systems

In FIG. 2, the reference light amount adjusting unit 170 includes two

optical systems

In this case, as described above, the optical collimator driver 174 determines the target intensity of the reference light signal based on the previous interference signal strength, and sets the optical output angle of the second optical collimator (not shown) according to the target intensity of the reference light signal. do.

Claims

In the optical interference tomography apparatus,

A light source for outputting light;

The light output from the light source is divided into a first optical signal and a second optical signal, and outputted, and the feedback and coupling of the measurement light signal corresponding to the first optical signal and the reference light signal corresponding to the second optical signal are respectively received and combined. interferometer;

An object measuring unit configured to irradiate the measurement object with the first optical signal output through the interferometer and to feed back the measurement light signal reflected from the measurement object to the interferometer;

A reference light generator for irradiating the reference mirror with the second optical signal output through the interferometer and feeding back the reference light signal reflected from the reference mirror to the interferometer;

A photodetector for measuring interference signal strengths of the measurement light signal and the reference light signal coupled through the interferometer; And

And a reference light amount adjusting unit configured to control an incident angle of the second optical signal into the reference mirror or a reflection angle from the reference mirror to be changed based on the interference signal strength previously measured.
The method of claim 1,

The reference light amount adjusting unit,

Determine a target intensity of the reference light signal based on the photosaturation threshold of the photodetector and the previously measured interference signal strength,

And an angle of incidence of the second optical signal to the reference mirror or a reflection angle of the reference mirror based on a target intensity of the reference light signal.
The method of claim 2,

A reference generation unit may be further configured to generate a normalized light quantity map for the reference light signal by matching at least one of an incident angle of the second optical signal to the reference mirror and a reflection angle from the reference mirror for each reference light signal in advance.

The reference light amount adjusting unit,

And an incident angle or a reflection angle matched to a target intensity of the reference light signal from the normalized light amount map.
The method of claim 1,

The reference light amount adjusting unit,

At least one optical system for reflecting the second optical signal output toward the reference mirror at a predetermined reflection angle, respectively; And

An optical system driver configured to set the reflection angle for each optical system based on the previously measured interference signal strength, and rotate the optical system for each optical system in a direction and an angle set based on the reflection angle,

When a plurality of optical systems are included in the reference light amount adjusting unit,

And the plurality of optical systems are disposed to face each other such that light reflected from any one of the other optical systems is incident thereon.
The method of claim 4, wherein

The plurality of optical systems,

A first optical system for reflecting the second optical signal output in a first travel direction in a second travel direction different from the first travel direction; And

And a second optical system reflecting the optical signal reflected from the first optical system in the first travel direction and incident on the reference mirror.
The method of claim 1,

The target measuring unit includes a first optical collimator that focuses the first optical signal output through the interferometer and outputs parallel light toward the measurement object.

And the reference light generating unit includes a second optical collimator for collecting the second optical signal output through the interferometer and outputting the second optical signal as parallel light toward the reference mirror.
The method of claim 6,

The reference light amount adjusting unit,

An optical collimator driver configured to set an optical output angle of the second optical collimator based on the previously measured interference signal strength, and rotate the second optical collimator to a direction and an angle set based on the optical output angle. Optical coherence tomography device.
The method of claim 1,

The reference light amount adjusting unit,

And a reference mirror driver configured to set a reflection angle of the reference mirror based on the previously measured interference signal strength, and rotate the reference mirror in a direction and an angle set based on the reflection angle.
The method of claim 1,

And a tomography image processor configured to signal-process a value of the interference signal intensity measured by the photodetector to generate a tomography image of the measurement object.
The method of claim 1,

The previously measured interference signal strength is

And an initial value of an interference signal intensity according to the measurement light signal and the reference light signal initially fed back to the interferometer with respect to the measurement object.
In the optical interference tomography method through the optical interference tomography apparatus,

(a) dividing and outputting the light output from the light source into a first optical signal and a second optical signal;

(b) irradiating the first optical signal to a measurement object and irradiating the second optical signal to a reference mirror;

(c) receiving feedback of a measurement light signal reflecting the first optical signal from the measurement object and a reference light signal reflecting the second optical signal from the reference mirror;

(d) combining the fed back measurement light signal and reference light signal; And

(e) measuring interference signal strength based on the combined measurement light signal and the reference light signal,

In step (b),

And irradiating the second optical signal by applying an angle of incidence of the second optical signal to the reference mirror or a reflection angle of the reference mirror set based on the interference signal strength previously measured.
The method of claim 11,

Before step (a) above,

(f) determining a target intensity of the reference light signal based on a photosaturation threshold of the photodetector measuring the interference signal strength and the previously measured interference signal strength; And

and (g) setting an angle of incidence of the second optical signal into the reference mirror or a reflection angle of the reference mirror based on a target intensity of the reference light signal.
The method of claim 12,

Before step (g),

(h) generating a normalized light quantity map for the reference light signal by matching the incident angle of the second optical signal to the reference mirror or the reflection angle at the reference mirror for each reference light signal intensity,

Step (g) is

And detecting the incident angle or the reflected angle matched to a target intensity of the reference light signal from the normalized light quantity map.
The method of claim 11,

The previously measured interference signal strength is

And an initial value of an interference signal intensity according to the measurement light signal and the reference light signal initially fed back to the measurement object.
The method of claim 11,

After step (e),

And generating a tomography image of the measurement object by signal processing the measured value of the interference signal strength.