KR20120097237A - Polarization Sensitive-Optical Coherence Imaging System - Google Patents

Abstract

The present invention relates to a polarization-sensitive optical coherence tomography apparatus, wherein a single detector-based apparatus is transmitted by sequentially transmitting vertical and horizontal component signals of optical signals of an object to one detector using a broadband high-speed optical switch. By connecting the probe through the laser arm unit which has various degrees of freedom and at the same time a constant optical path is formed therein, the same fluidity as the fiber-optic probe is secured, which is very convenient for the user and the subject. The present invention provides a polarization-sensitive photocoherence tomography imaging apparatus capable of measuring various signal values, unlike the optical fiber probe.

Description

Polarization Sensitive-Optical Coherence Imaging System

The present invention relates to a polarization sensitive photocoherence tomography apparatus. More specifically, a single detector-based device can be configured by transmitting vertical and horizontal component signals of optical signals of an object to one detector one by one using a broadband high-speed optical switch, one at a time. By connecting the probe through the laser arm unit having a constant optical path therein, the same fluidity as that of the fiber-optic probe can be ensured to provide a very convenient user convenience to the user and the examinee. Unlike a probe, the present invention relates to a polarization sensitive photocoherence tomography apparatus capable of measuring various signal values.

Recently, optical and optical technologies have been widely applied to biological science and medical engineering such as medical heavy ion accelerators, ophthalmic procedures using adaptive optics, various laser procedures, and early diagnosis of cancer cells using fluorescence. In particular, biophotonics imaging technology is a technology that records and analyzes various life phenomena occurring in biomolecules, cells, and living bodies as an image. Convergence technology is regarded as the next generation national growth engine as well as the development of related disciplines.

Optical coherence tomography (OCT) is a device that photographs living tissues or cells in high resolution in real time using light that is harmless to the human body, and allows non-contact and non-invasive observation of the inside of a living body. The difference between soft tissues can be distinguished, resulting in more accurate images.

The optical coherence tomography (OCT) is based on a wide band of light sources and a Michelson interferometer. Due to the development of light sources and technologies, applications such as ophthalmology, dermatology, gastroenterology, and dentistry continue to expand.

Polarization Sensitive-Optical Coherence Tomography (PS-OCT) is an advanced bio-imaging technology that has recently been in the spotlight, enabling non-invasive tomographic imaging of the internal structure of biological tissues, like OCT systems. It is a technology that can obtain polarization change, phase shift by birefringence, optical axis information, etc. of light reflected or scattered from an asymmetric material such as collagen fiber which reacts easily. Since most tissues and organs of the human body are made of collagen, this technique is very useful for medical diagnosis.

The technology has recently been studied on thermal damage, wound healing, photo-aging in the skin, caries in the teeth, retinal nerve fiber layers and corneas in the eye, cervical cancer and colorectal cancer. It is applied to various medical fields such as diagnosis of laryngeal cancer. In addition, technologies for speeding up image acquisition, techniques for obtaining high resolution images, techniques for reducing production costs, and techniques for minimizing noise effects are being actively conducted for clinical applications.

Unlike photocoherence tomography (OCT), polarization-sensitive photocoherence tomography (PS-OCT) uses a polarization beam splitter (PBS) at the detector to acquire polarization information for tissue samples with two detectors. do.

1 is a block diagram schematically illustrating a configuration of a general polarization-sensitive photocoherence tomography apparatus according to the prior art.

In the prior art, a polarization-sensitive optical coherence tomography (PS-OCT) apparatus generally includes a light source 50, an optical unit 10, a probe 60, two detection units 30a and 30b, a computer 40, and the like. It is composed of one system. The optical unit 10 includes a linear polarizer 13, a light splitter 11, a polarization splitter 12, and two quarter wave plates 14 and 15. 60 generally consists of an optical scanner 62 and an objective lens 63.

The light generated from the light source 50 passes through the linear polarizer 13 of the optical unit 10, and only the horizontally polarized light passes through the light splitter 11, and the reference stage R having the reference mirror R1 and the inspection object. It is dispensed to the sample stage T with (P). The light that goes to the reference stage R passes through the first quarter wave plate QWP 14 inclined at 22.5 ° and is reflected by the reference mirror R1, and then again the first quarter wave plate QWP. 45 ° linearly polarized. At this time, the vertical and horizontal components of the light have the same size. Light directed to the sample stage T is circularly polarized through the second quarter wave plate (QWP) 15 inclined at 45 °, and the optical scanner 62 and the objective lens 63 of the probe 60 are rotated. It is irradiated to the inspection object P past it. If the inspection object P is a mirror that is a perfect reflector, the circularly polarized light is reflected again and passes through the second quarter wave plate QWP 15 through the objective lens 63 and the optical scanner 62. In the light, only the vertical component exists. Reference mirror when the light travel distance from the light splitter 11 to the reference mirror R1 of the reference stage R and the light travel distance from the light splitter 11 to the inspection object P of the sample stage T are equal. The light reflected from R1 and the light reflected from the inspection object P meet again at the optical splitter 11 to generate an interference signal. The generated interference signal passes through the polarization splitter (PBS) 12 and is divided into vertical and horizontal components, and the light of the vertical component is received by the first detector 30a and the light of the horizontal component is received by the second detector 30b. Each is finally detected. In the case of a spectral-domain polarization sensitive photocoherence tomography (PS-OCT) detector, the detectors 30a and 30b are applied with a spectrometer composed of a transmisssion grating, a lens, and a line scan camera. The detection signals detected by the detectors 30a and 30b are transmitted to the computer 40 and processed by a calculation program in the computer 40 to be implemented as real-time image information.

The polarization sensitive photocoherence tomography (PS-OCT) device according to the prior art is composed of such a basic system. The horizontal components are respectively detected to obtain polarization information for the inspection object P. As two detectors are used, the following serious problem occurs.

1) High cost problem for making two detectors

2) The problem of distortion of the detection signal due to the inconsistency of the two detectors

3) Time delay of image implementation and complexity of algorithm due to need of software-based correction algorithm for distortion of detection signal

4) Difficulties in hardware system configuration, alignment, and trigger configuration

On the other hand, the probe 60 of the conventional polarization-sensitive photocoherence tomography apparatus (PS-OCT) according to the prior art is composed of a microscope type in which the sample stage T is fixed or free for medical diagnosis and biosample measurement. It is composed of a fiber-based probe with high fluidity in a movable form. However, the microscope type probe has a fixed form and no fluidity, so its use range is very limited, and the optical fiber-based probe is sensitive to polarization due to the characteristics of the optical fiber, making it difficult to use in the sample stage (T). Only the relative value, not the absolute value, of the birefringent signal, which is a signal of the imaging device (PS-OCT), can only be measured, and there is a problem that polarization extinction (DOP), which is one of useful information for diagnosis, cannot be measured.

The present invention has been invented to solve the problems of the prior art, and an object of the present invention is to transmit vertical and horizontal component signals for optical signals of an object to one detector sequentially one by one using a broadband high-speed optical switch. This enables the construction of a single detector-based device, thereby reducing the cost of eliminating one detector, overcoming distortion of the video signal due to the manufacture of two detectors, and simplifying the trigger signal. The present invention provides a polarization-sensitive photocoherence tomography imaging apparatus capable of minimizing measurement time in that a software / hardware-based image signal correction algorithm is unnecessary.

Another object of the present invention is to connect the probe through a laser arm unit having a variety of degrees of freedom and at the same time a constant optical path is formed therein, to secure the same fluidity as the probe of the optical fiber-type probe can be moved freely with the user Polarization-sensitive light that can provide the subject with excellent usability and can measure the polarization extinction (DOP) and circular polarization extinction (DOCP) and the absolute value of the birefringence signal, unlike the optical fiber probe. A coherence tomography imaging device is provided.

According to the present invention, in the polarization-sensitive photocoherence tomography apparatus capable of non-invasive inspection of the inside of the inspection object, the light generated from the light source is distributed in a polarized state, and a part of the inspection object proceeds to the inspection object of the sample stage through the probe. A part of the optical unit in which the reflected light from the reference stage and the sample stage is gathered again and then interfered with each other, and the mutually interfered light is separated into vertical and horizontal components; A detection unit which sequentially receives and detects light of vertical and horizontal components separated through the optical unit; An optical switching unit which switches through the optical unit such that the separated vertical and horizontal components are sequentially incident on the detection unit; And a computer that receives the detection signal from the detection unit and arithmizes and processes the detection signal and outputs the signal as an image signal of an object to be inspected in the sample stage.

In this case, the light switching unit includes a first and a second parallel light lens which passes through the optical unit and is provided so that the light of the vertical and horizontal components separated separately; First and second polarization adjusters for adjusting the polarization states of the light passing through the first and second parallel light lenses, respectively; And an optical switch for switching so that the light passing through the first and second polarization controllers may proceed sequentially.

The optical switch unit may further include a third polarization controller for adjusting the polarization state of the light passing through the optical switch.

In addition, the detector may be applied to one spectrometer.

The optical unit may further include a linear polarizer for converting light generated from the light source into a horizontal polarization state; A light splitter configured to distribute the light passing through the linear polarizer to the reference stage and the sample stage, and the light re-reflected from the reference stage and the sample stage gather again and interfere with each other; A first quarter wave plate disposed to linearly polarize light passing through the light splitter from the light splitter to the reference stage and reflected from the reference splitter to the light splitter; A second quarter wave plate disposed to circularly polarize light passing through the light splitter from the light splitter to the sample stage and reflected from the sample splitter to the light splitter; And a polarization splitter that separates light interfering with each other in the light splitter into vertical and horizontal components.

In addition, the reference stage may be applied as a reference mirror that is a complete reflector.

On the other hand, the probe may be coupled to the optical unit through a separate laser arm unit to be free to move independently of the optical unit.

In this case, the laser arm unit may be configured to form an optical path between the optical unit and the probe in an internal space.

In addition, the laser arm unit is formed in the form of a hollow pipe, each of the plurality of joint arms are sequentially coupled to each other rotatably; And a reflection mirror coupled to the inside of the joint cancer and reflecting light to propagate light through the joint cancer internal space.

In this case, the plurality of joint cancers may be sequentially coupled such that mutually adjacent joint arms are disposed at a right angle, and may be rotatably coupled around a longitudinal rotation axis with respect to any one of mutually adjacent joint arms.

In addition, a separate connecting tube may be coupled to the joint arm connected to the optical unit and the joint arm connected to the probe among the plurality of joint arms to be detachably connected to the optical unit and the probe, respectively.

The probe may further include a probe case coupled to one end of the laser arm unit; An optical scanner mounted inside the probe case to reflect light to the laser arm unit or the inspection object; And an objective lens coupled to one side of the probe case, wherein light emitted from the optical unit through the laser arm unit is reflected by the optical scanner and irradiated to the inspection object through the objective lens, and the inspection Light reflected from an object may be configured to be incident to the optical scanner through the objective lens and then reflected to the laser arm unit to travel to the optical unit.

The light switching unit may further include: first and second parallel light lenses passing through the optical part and separately provided with separate vertical and horizontal components of light; An optical switch for switching to sequentially output light of the vertical and horizontal components; And a polarization controller for adjusting a polarization state of light input and disposed at at least one of the front end and the rear end of the optical switch, wherein the polarization adjuster comprises a spectrum of the vertical and horizontal component light and the vertical and horizontal component light. The signal may be adjusted such that the depth component through fast Fourier transform through the computer is zero.

According to the present invention, a single detector-based device may be configured by transmitting vertical and horizontal component signals of an optical signal of an object to be sequentially transmitted to one detector one by one using a broadband high-speed optical switch. As a result, one detector can be eliminated, resulting in significant cost savings, overcoming the distortion of the video signal caused by two detectors, simplified trigger signals, and software / hardware-based video. Since the signal correction algorithm is unnecessary, the measurement time can be minimized.

In addition, by connecting the probe through a laser arm unit having a variety of degrees of freedom of movement and a constant optical path therein, it is possible to freely move the probe by securing the same fluidity as the probe of the optical fiber type, according to the user and the subject It is very easy to use, and unlike the optical fiber probe, it can measure the polarization extinction (DOP) and circular polarization extinction (DOCP) and the absolute value of the birefringence signal. It is effective to identify more accurate and various characteristics.

1 is a block diagram schematically illustrating a configuration of a general polarization sensitive photocoherence tomography apparatus according to the prior art;
2 is a block diagram schematically illustrating a configuration of a polarization sensitive photocoherence tomography imaging apparatus according to an embodiment of the present invention;
3 is a block diagram schematically illustrating a detailed configuration of an optical switch unit and a detection unit according to an embodiment of the present invention;
4 is a block diagram schematically illustrating a configuration of a polarization sensitive photocoherence tomography imaging apparatus according to another embodiment of the present invention;
5 is a conceptual diagram schematically showing the configuration of a laser arm unit and a probe according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

2 is a block diagram schematically illustrating a configuration of a polarization sensitive photocoherence tomography imaging apparatus according to an embodiment of the present invention, and FIG. 3 schematically illustrates a detailed configuration of an optical switch unit and a detection unit according to an embodiment of the present invention. It is a block diagram shown by.

The polarization-sensitive optical coherence tomography apparatus (PS-OCT) according to the embodiment of the present invention is configured to detect light separated into vertical and horizontal components sequentially in one detector using an optical switch. And an optical unit 100 for distributing light generated from the 500, one detection unit 300, an optical switching unit 200, and a computer 400. In addition, the probe 600 is mounted to the optical unit 100 to acquire the polarization information from the test object P in the sample stage T having the test object P.

The optical unit 100 includes a linear polarizer 130 for converting light generated from the light source 500 into a polarization state, and a light splitter 110 for distributing the polarized light to the reference terminal R and the sample terminal T. And a first quarter wave plate 140 and a second quarter wave plate 150 arranged to pass light, which is distributed from the light splitter 110, and passes through the reference stage R. The polarization splitter 110 is provided to reflect light from the sample stage T and then gather again to separate the mutually interfering light into vertical and horizontal components. Therefore, in the optical unit 100, light generated from the light source 500 is distributed in a polarized state, and a part of the optical unit 100 proceeds to the inspection object P of the sample stage T through the probe 600, and a part of the reference stage R is used. ), And the light propagated to the reference stage (R) and the sample stage (T), respectively, is reflected from the reference stage (R) and the sample stage (T), gathers again in the optical unit (100), and mutually interferes with each other. The light is separated into light of vertical and horizontal components.

As described above, light having vertical and horizontal components separated through the optical unit 100 is sequentially incident and detected by one detection unit 300 by the switching operation of the light switching unit 200, and then is detected by the detection unit 300. The detection signal is transmitted to the computer 400, arithmetic processing by the computer 400 is output as an image signal for the inspection object (P).

Hereinafter, a detailed configuration and operation flow of the polarization sensitive photocoherence tomography apparatus will be described in detail.

The light source 500 generating light transmits light to the optical unit 100 by applying a high speed wavelength conversion low coherence light source. The average time interval at which an optical wave reaching a point in any space vibrates predictably and maintains a sinusoidal shape without changing the phase is called coherence time. This is called temporal coherence of light waves. It is a measure of decision. Observing from a fixed point in space, the advancing light waves oscillate in the form of a sine function only during time intervals in which the phase remains constant. The spatial length of the regularly oscillating light waves until the phase changes arbitrarily is called the coherence length and is a measure of how purely the light waves are spectroscopically. The low coherence light source is a light source having a short interference distance of light waves and has been widely used in optical coherence tomography imaging devices because of its wide spectrum band.

The light generated from the light source 500 passes through the linear polarizer LP 130 (or the polarization splitter PBS) of the optical unit 100 and is converted into light polarized in the horizontal direction.

The purely horizontally polarized light is distributed while passing through a beam splitter (BS) 110 to travel to the reference stage R in one path and to the sample stage T in the other path. Here, the reference stage R may be applied to the reference mirror R1 which is a complete reflector.

Light traveling to the reference stage R passes through a first quarter wave plate (QWP) 140 inclined at 22.5 ° with respect to the horizontal. Light passing through the first quarter wave plate 140 inclined at 22.5 ° is reflected by the reference mirror R1 and passes through the quarter wave plate 140 at 22.5 ° to the light splitter 110. Will come back. At this time, the light returned to the optical splitter 110 has the same size and phase of the vertical component and the horizontal component in a 45 ° linearly polarized state, which is theoretically experimentally proved in the optical field, and thus a detailed description thereof will be omitted. .

The light traveling to the sample stage T passes through the second quarter wave plate QWP 150 inclined at 45 ° with respect to the horizontal, and passes through the probe 600 to the test object P of the sample stage T. Will be joined. In this case, the probe 600 includes an optical scanner 620 for reflecting incident light and an objective lens 630 for focusing light, which is distributed from the light distributor 110 and proceeds to the sample stage T. The light is reflected by the optical scanner 620, focused by the objective lens 630, and then incident to the inspection object P of the sample stage T. In this case, the light is circularly polarized based on the horizontal component, and the light of the circularly polarized component is scattered or retroreflected from the test object P and causes a change to elliptical polarization according to the optical characteristics of the test object P. The light scattered or retroreflected from the object P is returned to the same path, and then returns to the light splitter 110 through the second quarter wave plate 150 inclined at 45 °. At this time, the light returned to the light splitter 110 has only a vertical component. At this time, if the sample is a reflector without a birefringent material such as collagen, the light returning to the light splitter 110 has only a vertical component.

At this time, when the moving distance of the light from the light splitter 110 to the reference mirror R1 of the reference stage R and the light moving distance from the light splitter 110 to the inspection target P of the sample stage T are the same. The light reflected from the reference mirror R1 and the light reflected from the inspection object P meet again at the light splitter 110 to generate an interference signal. The generated interference signal passes through the polarization splitter 110 and is separated into vertical and horizontal components.

As described above, light separated into vertical and horizontal components is detected by being sequentially incident to the detection unit 300 through the light switching unit 200, and the light switching unit 200 includes the polarization splitter 110 as shown in FIG. 3. Passing through the first and second parallel light lenses 210a and 210b and the first and second parallel light lenses 210a and 210b respectively provided to separate and pass the separated vertical and horizontal components, respectively. Optical switch 230 for switching operation so that the light passing through the first and second polarization controllers 220a and 220b and the light passing through the first and second polarization controllers 220a and 220b sequentially progress, respectively. It is configured to include). In this case, the optical switch 230 is preferably a high-speed optical switch capable of rapid operation. In addition, the optical switching unit 200 may further include a separate third polarization controller 220c to adjust the polarization state of the light passing through the optical switch 230.

Accordingly, the light of the vertical and horizontal components separated through the polarization splitter 110 of the optical unit 100 is respectively the first and second parallel light lenses 210a and 210b and the first and second polarization adjusters 220a and 220b. After passing through), the light switch 230 sequentially enters the detector 300.

Since the detection unit 300 sequentially detects vertically and horizontally separated light, only one unit is provided unlike the prior art, and may be applied as a photodiode or a spectroscope according to a use environment. When applied to the spectroscope, the spectrometer may be composed of a collimator 310, a transmission diffraction grating 320, a lens 330 and a line scanning camera 340, as shown in FIG. The light passing through the collimator 310 becomes parallel light, is converted into spectral information on the wavelength by the transmission diffraction grating 320, and is incident to the line scanning camera 340 by the lens 330. Sent to computer 400.

At this time, the optical signal information of the vertical and horizontal components detected by the detector 300 should be adjusted to be as close as possible through technical correction of the polarization controllers 220a, 220b, 220c of the optical switching unit 200 and the detector system. That is, when converting the vertical and horizontal components of the light into depth information through the Fast Fourier Transform (FFT), both signals must be adjusted to be a zero depth signal at the zero depth point. It may be performed through the correction of the polarization controller (220a, 220b, 220c) provided in the (200).

That is, the polarization controller matches the phase and magnitude of the spectrum with respect to the light of the vertical and horizontal components, and the depth information, which is the depth position value of the signal of the vertical and horizontal components, is 0 using the depth information obtained through the fast Fourier transform. To adjust the detection stage.

The computer 400 converts and receives the detection signal of the detection unit 300 into a digital signal, and receives the received digital signal by K-domain calibration and IFFT (Inverse fast) by a calculation program in the computer 400. real time video information through fourier transform). In addition, the magnitude and phase values of the vertical and horizontal components of light are obtained through the fast Fourier transform, and the Stokes parameter values are obtained from the values obtained by the fast Fourier transform to obtain degree of polarization (DOP) and circular polarization therefrom. Degree of circular polarization (DOCP) can be measured.

The object to be inspected horizontal component Ex of the optical signal is a light emitted from the (P) in the electromagnetic field, as when the vertical component Ey, each component can be expressed as follows.

Using this, Stokes variables (S ₀ , S ₁ , S ₂ , S ₃ ) can be obtained as follows.

At this time, the polarization extinction (DOP) and circular polarization extinction (DOCP) can be obtained through the following equation.

In this case, the polarization extinction degree (DOP) indicates the change state of the polarization component with respect to light, and the circular polarization extinction degree (DOCP) indicates the change in polarization of the circularly polarized light, by using the tissue of the test object (P) Understand the internal condition.

That is, when the uniformly polarized light passes through a medium having a high scattering coefficient such as a biological tissue having an asymmetric molecular structure such as collagen, the polarization component is changed by factors of dispersion and density of materials. The change in polarization component is regarded as one of the excellent control mechanisms in the optical imaging method of living tissue. In general, the change in polarization is correlated with the wavelength of the incident light and the size of the medium. If the size of the scatterer is larger than the wavelength range, the linear polarization property is maintained longer than the circular polarization. If the wavelength range is larger than the scatterer, the circularly polarized light maintains the polarization component longer than the linearly polarized light.

Such polarization extinction (DOP) and circular polarization extinction (DOCP), for example, when a cell change such as a tumor occurs inside the living tissue, the scattering coefficient for the incident light is changed and eventually the polarization extinction ( Changes in DOP) and circular polarization extinction (DOCP), which serves as an important basis for distinguishing characteristics of biological tissues.

The polarization extinction degree (DOP) and circular polarization extinction degree (DOCP) can not measure the value due to the characteristics of the optical fiber when the optical unit 100 and the probe 600 is connected through the optical fiber, an embodiment of the present invention Since the probe 600 is not connected to the optical unit 100 through an optical fiber, the polarization extinction degree (DOP) and the circular polarization extinction degree (DOCP) can be obtained. In addition, the probe 600 according to an embodiment of the present invention is configured in such a way that the fluidity can be largely maintained even without using an optical fiber, which will be described with reference to FIGS. 4 and 5.

Meanwhile, in the polarization-sensitive optical coherence tomography imaging apparatus according to the exemplary embodiment of the present invention, as described above, light separated into vertical and horizontal components through the optical unit 100 is sequentially detected by using the optical switch 230. By being incident to 300, unlike the prior art, two detectors are not required, and the entire system can be configured with only one detector. Therefore, it is about twice the cost reduction compared to the prior art, can overcome the distortion of the video signal due to the two detectors, can simplify the trigger signal, software / hardware-based video signal correction algorithm This eliminates the need to minimize measurement time.

4 is a block diagram schematically illustrating a configuration of a polarization-sensitive photo coherence tomography imaging apparatus according to another embodiment of the present invention, and FIG. 5 illustrates a configuration of a laser arm unit and a probe according to an embodiment of the present invention. It is a conceptual diagram schematically shown.

As described above, the polarization-sensitive photocoherence tomography imaging apparatus according to the embodiment of the present invention is configured in such a way that the fluidity is large so that the probe 600 can freely move independently of the optical unit 100. Such a probe 600 Is not a structure connected to the optical unit 100 by using the optical fiber is configured in a structure connected to the optical unit 100 through a separate laser arm unit 700.

In this case, the laser arm unit 700 is configured such that an optical path between the optical unit 100 and the probe 600 is formed in the internal space, and thus, light flowing between the optical unit 100 and the probe 600 is optical fiber. Since it is configured to pass through the internal space of the laser arm unit 700 without moving through, the polarization extinction (DOP) and circular polarization extinction (DOCP) that can not be measured through the optical fiber probe as described above Not only can be measured, but also the absolute value of the birefringent signal, which is a signal of a polarization sensitive photocoherence tomography apparatus, can be measured. In addition, since the fluidity of the probe 600 is secured through the laser arm unit 700, the probe 600 may move freely to the same extent as the optical fiber probe, thereby providing excellent convenience for the user and the examinee.

In other words, the probe 600 according to an embodiment of the present invention ensures the same fluidity as the optical fiber probe through the laser arm unit 700 in which the optical path is formed, and at the same time through the optical fiber probe. Various signal values that cannot be measured can be measured.

In more detail, as shown in FIG. 5, the laser arm unit 700 includes a plurality of joint arms 710 that are sequentially rotatably coupled to each other, and a reflective mirror that is respectively coupled to the inside of the joint arm 710. 720).

The joint arm 710 is formed in the form of a hollow pipe to allow light to pass through the inner space, and a plurality of joint arms 710 are sequentially arranged to be rotatable with each other. In this case, the plurality of joint arms 710 may be sequentially coupled such that mutually adjacent joint arms 710 are disposed at a right angle, and may be rotated about a longitudinal rotation axis with respect to any one of the mutually adjacent joint arms 710. Can be combined. In addition, any one of the plurality of joint arms 710 is connected to the optical unit 100 and another is connected to the probe 600, the joint arm 710 is connected to the optical unit 100 and the probe 600 ) Is equipped with a separate connector 701 so as to be connected to the optical unit 100 and the probe 600, respectively, and the connector 701 is threaded to be detachably connected to the optical unit 100 and the probe 600. S may be formed and screwed together.

The reflection mirror 720 is mounted inside each of the joint arms 710 and reflects the light along the optical path so that light can continuously pass through the interior spaces of the plurality of joint arms 710 arranged in a bent form. do. Accordingly, the reflection mirror 720 is formed differently depending on the arrangement of the joint arm 710, the joint arm 710 is rotated to each other so that the light can continuously pass even if the arrangement state changes It is mounted inside the arm 710.

For example, the laser arm unit 700 is sequentially coupled so that the six joint arms (710a, 710b, 710c, 710d, 710e, 710f) are perpendicular to each other, as shown in Figure 5, each joint arm (710a) , 710b, 710c, 710d, 710e, and 710f may be coupled to each other to rotate through a separate joint rotation ring 702 at the interconnect portion. The first joint arm 710a is coupled to one side of the connector 701 so as to be connected to the optical unit 100 and screwed to the optical unit 100, and the first joint arm 710a is connected to the connector 701. It is coupled to rotate about the rotation axis C1 relative to. At this time, the reflection mirror 720a at an angle reflecting the light so that the light incident through the connecting pipe 701 proceeds along the longitudinal direction in the inner space of the first joint arm 710a. ) Is mounted. The second joint arm 710b is disposed at a right angle to one end of the first joint arm 710a and coupled to rotate about the longitudinal rotation axis C2 of the first joint arm 710a. Inside the second joint arm 710b, a reflection mirror 720b is formed at an angle that reflects light so that light passing through the first joint arm 710a travels in the longitudinal direction in the internal space of the second joint arm 710b. Is mounted. In the same manner, the third joint arm 710c has a reflection mirror 720c mounted therein so as to reflect light in the longitudinal direction, and is coupled to one end of the second joint arm 710b at right angles, with a rotation axis C3 as the center. The fourth joint arm 710d, the fifth joint arm 710e, and the sixth joint arm 710f, which are coupled to rotate, and which are equipped with reflective mirrors 720, 720e, and 720f, respectively, are mounted in the same manner. Are sequentially coupled to each other, and are coupled to rotate about the rotational axes C4, C5 and C6, respectively. One side of the sixth joint arm 710f is coupled to the connection pipe 701 so as to be coupled to the probe 600, through which the probe 600 is detachably coupled.

According to this structure, since the laser arm unit 700 may rotate each joint arm 710 about a plurality of rotation axes, the probe 600 connected to the sixth joint arm 710f may have various degrees of freedom. Free to move. In addition, even if the probe 600 is moved freely by the rotation of the plurality of joint arms 710, the light path of the light through each joint arm 710 continues through each of the joint mirrors 720, respectively. Because it is configured to pass through 710, the optical path between optics 100 and probe 600 remains constant.

Accordingly, the probe 600 of the polarization-sensitive photo coherence tomography imaging apparatus according to the embodiment of the present invention may use a polarization extinction (DOP) and a circular polarization extinction (DOCP) as described above in a manner not using an optical fiber, Not only can the absolute value of the birefringent signal be measured, but the probe 600 can be moved freely, thereby providing a very good user convenience to the user and the test subject.

Meanwhile, the probe 600 coupled to the laser arm unit 700 may be mounted inside the probe case 610 and the probe case 610 coupled to one end of the laser arm unit 700 as shown in FIG. 5. And an optical scanner 620 reflecting light to the laser arm unit 700 and the inspection object P, and an objective lens 630 coupled to one side of the probe case 610. At this time, the probe case 610 is formed with a screw hole 611 on one side to be screwed with the connecting pipe 701 coupled to the sixth articulated arm 710f of the laser arm unit 700, the other side of the objective The coupling hole 612 is formed to couple the lens 630.

According to this structure, light that is distributed from the light distributor 110 of the optical unit 100 and proceeds to the sample stage T is incident to the optical scanner 620 of the probe 600 through the laser arm unit 700. It is reflected, which is focused through the objective lens 630 and irradiated to the inspection object P. The light irradiated onto the inspection object P is reflected again, passes through the objective lens 630, and then enters and is reflected by the optical scanner 620, which passes through the laser arm unit 700 to reflect the light of the optical unit 100. The light is incident on the divider 110 again, and interferes with the light reflected from the reference stage R, and is separated into vertical and horizontal components through the polarization divider 110. As described above, light separated into vertical and horizontal components is incident to one detection unit 300 sequentially through the light switching unit 200 and finally detected, and the detection signal by the detection unit 300 is sent to the computer 400. After transmission and processing, it is implemented as image information.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

100: optical unit 110: optical splitter
120: polarization splitter 200: light switching unit
220a, 220b, 220c: polarization controller 230: optical switch
300: detection unit 400; computer
500: light source 600: probe
700: laser arm unit 710: joint cancer
720: reflective mirror

Claims (13)

A polarization-sensitive photocoherence tomography apparatus capable of non-invasive inspection of the inside of an inspection object,
The light generated from the light source is distributed in the polarized state, and partly proceeds to the test object of the sample stage through the probe, and partly proceeds to the reference stage, and then the light reflected from the reference stage and the sample stage, respectively, gathers again and interferes with each other. An optical unit in which mutually interfering light is separated into vertical and horizontal components;
A detection unit which sequentially receives and detects light of vertical and horizontal components separated through the optical unit;
An optical switching unit which switches through the optical unit such that the separated vertical and horizontal components are sequentially incident on the detection unit; And
Receives the detection signal by the detection unit and arithmetic processing to output the image signal for the test object of the sample stage
Polarization sensitive photocoherence tomography imaging device comprising a.
The method of claim 1,
The optical switching unit
First and second parallel light lenses that pass through the optical unit and are provided to separately pass light of vertical and horizontal components separated from each other;
First and second polarization adjusters for adjusting the polarization states of the light passing through the first and second parallel light lenses, respectively; And
An optical switch for switching so that the light passing through the first and second polarization controllers proceeds sequentially
Polarization sensitive photocoherence tomography imaging device comprising a.
The method of claim 2,
The optical switch unit
And a third polarization controller for adjusting the polarization state of the light passing through the optical switch.
The method of claim 1,
The detector is applied to one spectroscopic polarization-sensitive photocoherence tomography apparatus.
The method of claim 1,
The optical unit
A linear polarizer for converting light generated from the light source into a horizontal polarization state;
A light splitter configured to distribute the light passing through the linear polarizer to the reference stage and the sample stage, and the light re-reflected from the reference stage and the sample stage gather again and interfere with each other;
A first quarter wave plate arranged to linearly polarize light passing through the light splitter from the light splitter to the reference stage and reflected from the reference stage to the light splitter;
A second quarter wave plate disposed to circularly polarize light passing through the light splitter from the light splitter to the sample stage and reflected from the sample splitter to the light splitter; And
Polarization splitter for separating the mutually interfering light into vertical and horizontal components in the optical splitter
Polarization sensitive photocoherence tomography imaging device comprising a.
The method of claim 5, wherein
And the reference stage is applied as a reference mirror which is a complete reflector.
7. The method according to any one of claims 1 to 6,
And the probe is coupled to the optical unit through a separate laser arm unit to freely move independently of the optical unit.
The method of claim 7, wherein
And the laser arm unit is configured to form an optical path between the optical unit and the probe in an internal space.
The method of claim 8,
The laser arm unit
A plurality of joint arms each formed in the form of a hollow pipe and sequentially coupled to each other rotatably; And
Reflecting mirrors respectively coupled to the inside of the joint cancer and reflecting light to propagate light through the inner space of the joint arm
Polarization sensitive photocoherence tomography imaging device comprising a.
The method of claim 9,
The plurality of joint cancers are sequentially coupled so that mutually adjacent joint cancers are disposed at a right angle, and are rotatably coupled around a longitudinal rotation axis with respect to any one of the mutually adjacent joint cancers. Imaging device.
11. The method of claim 10,
Polarization-sensitive optical coherence, characterized in that a separate connector is coupled to each of the joint arm and the joint arm connected to the probe of the plurality of joint cancer to be detachably connected to the optical unit and the probe, respectively. Tomographic Imaging Device.
The method of claim 8,
The probe is
A probe case coupled to one end of the laser arm unit;
An optical scanner mounted inside the probe case to reflect light to the laser arm unit or the inspection object; And
An objective lens coupled to one side of the probe case
Includes, the light emitted from the optical unit through the laser arm unit is reflected by the optical scanner is irradiated to the inspection object through the objective lens, the light reflected from the inspection object through the objective lens And incident on the optical scanner and then reflected by the laser arm unit to advance to the optical unit.
The method of claim 1,
The optical switching unit
First and second parallel light lenses that pass through the optical unit and are provided to separately pass light of vertical and horizontal components separated from each other;
An optical switch for switching to sequentially output light of the vertical and horizontal components; And
A polarization controller arranged at one or more of the front and rear ends of the optical switch and configured to adjust the polarization state of the input light,
The polarization regulator is polarized light sensitive photocoherence tomography, characterized in that the vertical and horizontal component light spectrum and the vertical and horizontal component light signal is adjusted so that the depth component through the fast Fourier transform through the computer is zero. Imaging device.

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