CN112587086A - Dual-mode polarization optical coherent imaging system and imaging method thereof - Google Patents

Abstract

The invention relates to a dual-mode polarized optical coherence tomography system and an imaging method thereof. The polarized light detection technology is used to form a first polarized optical coherent imaging system and a second polarized optical coherent imaging system through a polarized beam splitter cube and an optical fiber polarizer assembly. The imaging system constructs a pair of orthogonal polarized light structures, which do not crosstalk each other during detection, and are not easily interfered by stray light. Moreover, the second polarization optical coherent imaging system has the characteristics of fast scanning speed and large scanning depth to roughly measure the structure of the human eye and lock the region of interest, and then the first polarization optical coherent imaging system realizes the detection of the region of interest. High-resolution imaging solves the problem that the existing technology cannot take into account the large-scale and high-precision human eye structure imaging, and can simultaneously realize large-scale and high-precision human eye structure measurement, meeting the detection requirements of femtosecond laser cataract surgery.

Description

A dual-mode polarization optical coherent imaging system and imaging method thereof

technical field

The invention relates to the technical field of medical devices, in particular to a dual-mode polarization optical coherent imaging system and an imaging method thereof.

Background technique

Femtosecond laser-assisted cataract surgery is an ophthalmic surgery that uses femtosecond laser pulses, optical coherence tomography, and computer technology to automate and intelligentize several key steps in traditional cataract surgery, such as artificial nucleus fragmentation. The position and contour of the lens and the anterior and posterior capsules, especially the position and contour of the posterior capsule, need to be accurately measured intraoperatively. In traditional femtosecond laser-assisted cataract surgery, when the measurement data is inaccurate, the posterior capsule is easily damaged and the vitreous fluid leaks. In addition, the femtosecond laser is prone to incomplete nuclear fragmentation, resulting in residual lens epithelial cells in the capsular bag after phacoemulsification. Obvious occlusion of light entering the eyeball along the visual axis will cause the patient's visual acuity to decrease significantly after femtosecond laser-assisted cataract surgery, thereby causing postoperative cataract.

Because OCT has the characteristics of non-contact, no radiation, high detection sensitivity, and no damage, OCT has become a standard technique for measuring human eye structure in ophthalmic surgery. Optical coherence tomography human eye structure imaging technology is a Michelson interferometer using the principle of low coherence. There are three main technical solutions: time-domain optical coherence tomography, spectral-domain optical coherence tomography, and swept-frequency optical coherence tomography. Time-domain optical coherence tomography is the first generation of optical coherence tomography, which uses the interference of ballistic photons and serpentine photons scattered on biological tissue with the reflected light on the reference arm to generate interference fringes. The structural information of the scattering tissue is calculated, but the scanning speed of this method is limited; the spectral domain optical coherence tomography technology is the second generation of optical coherence tomography technology. Although the detection accuracy of this method is high, the detection range is relatively limited; the swept-frequency optical coherence tomography technology is the third-generation optical coherence tomography technology, and this technology and the spectral domain optical coherence tomography technology are both Fourier domain optics. Coherence tomography technology, although the scanning speed is fast, the scanning depth is large, and the signal-to-noise ratio of the collected signal is high, but due to the discrete wavelength sampling, the accuracy of the detection results is lower than that of the spectral domain optical coherence tomography technology. The above three optical coherence tomography techniques are complex and difficult to construct an optical path when used in combination, so they are usually used alone in the prior art, so they can only have a single performance and cannot take into account multiple performances.

At present, there is no effective drug for postoperative posterior capsular cataract, and only surgery can be used, which brings inconvenience to patients. Traditional femtosecond laser-assisted cataract surgery lacks a system that can simultaneously achieve large-scale and high-precision imaging of human eye structures, and the detection accuracy of the position and boundary of the lens and posterior capsule is low, and it is easy to cause phacoemulsification to cause damage to the posterior capsule or A condition in which residual lens epithelial cells grow on the posterior membrane of the lens causing postoperative cataracts.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a dual-mode polarized optical coherent imaging system and an imaging method thereof. The dual-mode polarized optical coherent imaging system can realize large-scale and high-precision imaging of human eye structures, improve the lens and posterior capsule. The detection accuracy of the position and boundary can avoid the occurrence of post-operative cataract caused by phacoemulsification causing damage to the posterior capsule or the growth of residual lens epithelial cells in the posterior lens membrane.

The present invention provides, in one aspect, a dual-mode polarized optical coherent imaging system, comprising a first polarized optical coherent imaging system, a second polarized optical coherent imaging system, a central processing unit, and a data register connected through an electrical signal path, and an optical fiber The connected polarization beam splitter cube, scanning galvanometer, first optical channel, second optical channel and first focusing lens; the first polarization optical coherent imaging system and the second polarization optical coherent imaging system are respectively connected to the the polarization beam splitter cube;

Wherein, the scanning beams emitted by the first polarized optical coherent imaging system and the second polarized optical coherent imaging system are input into the polarized beam splitter cube for modulation to form two mutually orthogonal polarized beams, and the polarized beam splitter The beam cube combines the two orthogonal polarized lights and outputs the first combined light, and the first combined light is transmitted to the scanning galvanometer and the first optical channel in turn. Light splitting is performed in the optical channel, and the split light beam enters the second optical channel for reflection and then enters the first optical channel for beam combining to output a second combined beam light, and the second combined beam light passes through the The first focusing lens focuses on the target imaging area, the second combined beam is reflected by the target imaging area to form a reflected beam, and the reflected beam is split by the polarization beam splitter cube to form a first reflected beam and a second beam. Two reflected beams, the first reflected beam is transmitted back to the first polarized optical coherent imaging system for coherence with the corresponding reflected broadband reference beam to generate first coherent light, and the first coherent light is transmitted to the The central processing unit, the second reflected beam is transmitted back to the second polarized optical coherent imaging system and the corresponding reflected frequency sweep reference beam is subjected to heterodyne detection processing and then transmitted to the central processing unit, and the central processing unit performs a heterodyne detection process. After data analysis, the analysis result is transferred to the data register for saving.

In an embodiment of the present invention, the first reflected light beam and the second reflected light beam are mutually orthogonal polarization states.

In an embodiment of the present invention, the first polarized optical coherent imaging system includes a broadband light source connected by an optical fiber, a first optical fiber coupler, a first collimating lens, a dispersion compensator, a second focusing lens, a mirror, and The spectrometer and the second collimating lens are connected to the first fiber coupler through an optical fiber, wherein the broadband light beam emitted by the broadband light source is divided into a broadband reference beam and a broadband scanning beam through the first fiber coupler. The broadband reference beam is sequentially transmitted to the first collimating lens, the dispersion compensator, the second focusing lens and the reflecting mirror through an optical fiber to form a reflected broadband reference beam, and the broadband scanning beam passes through the second After the collimating lens, a broadband scanning parallel beam is formed, the broadband scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the first reflected beam, and the first reflected beam and the reflected broadband reference beam are transmitted to the The first coherent light is generated by coherence in the first fiber coupler, and the first coherent light is transmitted to the spectrometer for spectral analysis.

In an embodiment of the present invention, the spectrometer includes a third collimating lens, a reflective grating, a transmissive grating, a cylindrical lens, and a line scan camera connected in sequence through an optical fiber, wherein the first coherent light is incident on the After the third collimating lens, parallel coherent light is formed, and the parallel coherent light is incident on the reflective grating for first-order splitting to obtain a first-order split beam, and the first-order split beam is incident on the transmission grating The second-level splitting beam is obtained by performing two-level splitting in the second-level splitting beam, and the second-level splitting light beam is focused into the line scan camera through the cylindrical lens to obtain interference spectrum information.

In an embodiment of the present invention, the first polarized optical coherent imaging system further includes a linear displacement platform, the mirror is arranged on the linear displacement platform, and the linear displacement platform is driven to move by a voice coil motor, for adjusting the distance between the reflecting mirror and the second focusing lens.

In an embodiment of the present invention, the second polarized optical coherent imaging system includes a frequency swept light source connected by an optical fiber, a second optical fiber coupler, a third optical fiber coupler, an optical fiber polarizer assembly, a beam expander assembly, A parallel reflector assembly, a frequency shifter, a balanced detector, a high-speed acquisition card, a scanning trigger, and a fourth collimating lens, the optical fiber polarizer assembly includes a first optical fiber polarizer and a second optical fiber polarizer, so The beam expander assembly includes a first beam expander and a second beam expander, and the parallel reflector assembly includes a first parallel reflector and a second parallel emitter, wherein the beam emitted by the frequency swept light source passes through the The second fiber coupler is divided into a first beam and a second beam, the first beam is transmitted to the scan trigger through an optical fiber, and the second beam is divided into a swept reference beam and a frequency scan reference beam through the third fiber coupler Sweeping frequency scanning beam, the frequency swept reference beam is transmitted to the first optical fiber polarizer and the first beam expander in turn, and then reflected by the first parallel reflector and the second parallel reflector to form a reflection frequency sweep reference beam, the reflected frequency sweep reference beam is sequentially transmitted to the second beam expander, the frequency shifter, the second fiber polarizer and then transmitted to the balance detector, the frequency sweep The scanning beam passes through the fourth collimating lens to form a swept-frequency scanning parallel beam, and the swept-frequency scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the second reflected beam, the second reflected beam and the The reflected frequency sweep reference beam is transmitted to the balanced detector for heterodyne detection processing, and finally transmitted to the high-speed acquisition card and the central processing unit in sequence.

In an embodiment of the present invention, the scan trigger includes a photodetector, a fiber circulator, and a fiber Bragg grating sequentially connected through an optical fiber, and the fiber Bragg grating is used to generate a stable phase scan trigger signal to eliminate the Fixed pattern noise.

In an embodiment of the present invention, the dual-mode polarization optical coherent imaging system further includes a high-speed camera, the high-speed camera is connected to the data register through an electrical signal path and is connected to the first optical channel through an optical fiber, using The image of the target imaging area is presented in real time.

The present invention also provides an imaging method of a dual-mode polarization optical coherent imaging system, comprising the following steps:

A. The scanning beams emitted by the first polarized optical coherent imaging system and the second polarized optical coherent imaging system are transmitted to the polarized beam splitter cube for modulation to form two mutually orthogonal polarized lights, and the polarized beam splitter cube will be mutually orthogonal to each other. The crossed two beams of polarized light are combined and the first combined beam is output;

B. The first combined beam is transmitted to the scanning galvanometer and the first optical channel in turn, and the beam is split in the first optical channel. The split beam enters the second optical channel for reflection and then enters the first optical channel again. Combining beams is performed in the channel to output the second beam combining light;

C. The second combined beam is focused to the target imaging area by the first focusing lens, the second combined beam is reflected by the target imaging area to form a reflected beam, and the reflected beam is processed by the polarization beam splitter cube. splitting to form a first reflected beam and a second reflected beam;

D. The first reflected beam is transmitted back to the first polarized optical coherent imaging system for coherence with the corresponding reflected broadband reference beam to generate first coherent light, which is transmitted to the central processing unit after spectral analysis ;

E. The second reflected beam is transmitted back to the second polarized optical coherent imaging system and the corresponding reflected frequency swept reference beam is subjected to heterodyne detection processing and then transmitted to the central processing unit;

F. After the central processing unit performs data analysis, the analysis result is transmitted to the data register for storage.

In an embodiment of the present invention, the step D specifically includes the steps:

D1. The broadband light beam emitted by the broadband light source is divided into a broadband reference beam and a broadband scanning beam through the first fiber coupler;

D2. The broadband reference beam is sequentially transmitted to the first collimating lens, the dispersion compensator, the second focusing lens and the reflecting mirror through the optical fiber to form a reflected broadband reference beam;

D3. The broadband scanning beam passes through the second collimating lens to form a broadband scanning parallel beam, and the broadband scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the first reflected beam;

D4. The first reflected beam and the reflected broadband reference beam are transmitted to the first fiber coupler for coherence to generate the first coherent light, and the first coherent light is transmitted to a spectrometer for spectral analysis.

In an embodiment of the present invention, in the step D4, the specific steps of performing spectral analysis on the first coherent light are:

D41. The first coherent light is incident on the third collimating lens of the spectrometer to form parallel coherent light;

D42, the parallel coherent light is incident on the reflection grating of the spectrometer to perform first-order splitting to obtain a first-order split beam;

D43. The first-order split beam is incident on the transmission grating of the spectrometer to perform second-order splitting to obtain a second-order split beam;

D44. The second-order split light beam is focused into the line scan camera of the spectrometer through the cylindrical lens of the spectrometer to obtain interference spectrum information.

In an embodiment of the present invention, the step E specifically includes the steps:

E1. The light beam emitted by the frequency swept light source is divided into a first light beam and a second light beam by the second fiber coupler;

E2, the first light beam is transmitted to the scanning trigger through the optical fiber;

E3. The second light beam is divided into a frequency-sweeping reference beam and a frequency-sweeping scanning beam through the third fiber coupler;

E4. The frequency swept reference beam is transmitted to the first optical fiber polarizer and the first beam expander in turn, and then reflected by the first parallel reflector and the second parallel reflector to form a reflective frequency swept reference beam. The reflective frequency swept reference beam is The light beam is transmitted to the second beam expander, the frequency shifter, and the second optical fiber polarizer in sequence, and then transmitted to the balanced detector;

E5. The swept-frequency scanning beam is formed by a fourth collimating lens to form a swept-frequency scanning parallel beam, and the swept-frequency scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the second reflected beam;

E6. The second reflected beam and the reflected frequency sweep reference beam are transmitted to the balanced detector for heterodyne detection processing, and finally transmitted to the high-speed acquisition card and the central processing unit in sequence.

The first polarized optical coherent imaging system of the dual-mode polarized optical coherent imaging system of the present invention has the advantage of high-precision imaging provided by the spectral domain optical coherence tomography technology, and the second polarized optical coherent imaging system has the advantages of scanning Because of the advantages of fast scanning speed, large scanning depth, high signal-to-noise ratio of collected signals, and deep imaging of frequency optical coherence tomography technology, the dual-mode polarization optical coherence imaging system can realize large-scale and high-precision human eye structure Imaging to meet the detection needs of existing cataract surgery.

The dual-mode polarized optical coherent imaging system of the present invention utilizes the orthogonal polarized light measurement method, so that the scanning beams emitted by the first polarized optical coherent imaging system and the second polarized optical coherent imaging system do not interact with each other Crosstalk is generated, and because there is very little polarized light in the natural environment, the interference of stray light in the working process can be avoided, the signal-to-noise ratio of the measurement result is high, and the detection accuracy is high.

By combining the orthogonal polarization measurement method, the spectral domain optical coherence tomography technique and the frequency sweep optical coherence tomography technique, the invention can reduce the strict requirements on the dispersion performance of the single-mode fiber and the coating performance of the dichroic mirror in the common optical path measurement. In this way, it is beneficial to reduce the difficulty of constructing the overall optical path of the dual-mode polarization optical coherent imaging system, so that the overall optical path structure of the dual-mode polarization optical coherent imaging system is simple in structure, easy to implement, and low in construction cost.

Further objects and advantages of the present invention will be fully realized by an understanding of the ensuing description and drawings.

Description of drawings

FIG. 1 is a schematic diagram of the optical path structure of the dual-mode polarization optical coherent imaging system according to a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of an optical path structure of a first polarized optical coherent imaging system of the dual-mode polarized optical coherent imaging system according to the above preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of the optical path structure of the spectrometer of the dual-mode polarization optical coherent imaging system according to the above preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of an optical path structure of a second polarized optical coherent imaging system of the dual-mode polarized optical coherent imaging system according to the above preferred embodiment of the present invention.

5 is a schematic diagram of the optical path structure of the scanning trigger of the dual-mode polarization optical coherent imaging system according to the above-mentioned preferred embodiment of the present invention.

FIG. 6 is a flow chart of an imaging method of the dual-mode polarization optical coherent imaging system according to the above-mentioned preferred embodiment of the present invention.

Description of reference numerals: first polarized optical coherent imaging system 100; broadband light source 1; first fiber coupler 2; first collimating lens 4; dispersion compensator 5; second focusing lens 6; mirror 7; linear displacement stage 8; second collimating lens 9; spectrometer 3; third collimating lens 31; reflection grating 32; transmission grating 33; cylindrical lens 34; line scan camera 35; second polarized optical coherent imaging system 101; frequency light source 27; second fiber coupler 26; third fiber coupler 25; fiber polarizer assembly 29; beam expander assembly 21; parallel reflector assembly 20; frequency shifter 22; balance detector 23; high-speed acquisition card 24; scan trigger 28; photodetector 281; fiber circulator 282; fiber Bragg grating 283; fourth collimating lens 18; central processing unit 16; data register 17; polarization beam splitter cube 10; scanning galvanometer 11; An optical channel 13 ; a second optical channel 14 ; a first focusing lens 15 ; a high-speed camera 12 ;

Detailed ways

The following description serves to disclose the invention to enable those skilled in the art to practice the invention. The preferred embodiments described below are given by way of example only, and other obvious modifications will occur to those skilled in the art. The basic principles of the invention defined in the following description may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It should be understood by those skilled in the art that in the disclosure of the present invention, the terms "vertical", "horizontal", "upper", "lower", "front", "rear", "left", "right", The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and to simplify the description, rather than to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus the above terms should not be construed as limiting the invention.

It should be understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be one. The number may be plural, and the term "one" should not be understood as a limitation on the number.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be mechanical connection, electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

As shown in FIG. 1 to FIG. 6 , the specific structure of the dual-mode polarization optical coherent imaging system and the specific steps of the imaging method according to a preferred embodiment of the present invention are explained.

As shown in FIGS. 1 to 5 , the dual-mode polarized optical coherent imaging system includes a first polarized optical coherent imaging system 100 , a second polarized optical coherent imaging system 101 , a central processing unit 16 and a data register connected through electrical signal paths 17, and the polarization beam splitter cube 10, the scanning galvanometer 11, the first optical channel 13, the second optical channel 14 and the first focusing lens 15 connected by optical fibers; the first polarization optical coherent imaging system 100 and the The two polarized optical coherent imaging systems 101 are respectively connected to the polarization beam splitter cube 10 through optical fibers; wherein, the scanning beams emitted by the first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 are input to the After modulation is performed in the polarization beam splitter cube 10, two mutually orthogonal polarized lights are formed. The polarization beam splitter cube 10 combines the two mutually orthogonal polarized lights and outputs a first combined beam. The combined beam is transmitted to the scanning galvanometer 11 and the first optical channel 13 in turn, and the beam is split in the first optical channel 13, and the split beam enters the second optical channel 14 after being reflected and then enters the The beam is combined in the first optical channel 13 to output a second combined light, the second combined light is focused to the target imaging area by the first focusing lens 15, and the second combined light is passed through the The target imaging area is reflected to form a reflected beam, and the reflected beam is split by the polarization beam splitter cube 10 to form a first reflected beam and a second reflected beam, and the first reflected beam is transmitted back to the first polarized optical coherent beam The imaging system 100 is coherent with the corresponding reflected broadband reference beam to generate a first coherent light, the first coherent light is transmitted to the central processing unit 16 after spectral analysis, and the second reflected beam is transmitted back to the second The polarized optical coherent imaging system 101 performs heterodyne detection processing with the corresponding reflected frequency swept reference beam and transmits it to the central processing unit 16 . After the central processing unit 16 performs data analysis, it transmits the analysis result to the data register 17 save in.

It should be understood that, in this preferred embodiment of the present invention, the target imaging area is the human eye 19 . That is to say, the dual-mode polarized optical coherent imaging system of the present invention can be used for femtosecond laser cataract surgery, and realizes large-scale and high-precision imaging of human eye structures. In some embodiments of the present invention, the dual-mode polarization optical coherent imaging system can also be used in the field of cutting technology and measurement technology, and the invention does not limit the application field of the dual-mode polarization optical coherent imaging system.

In particular, after being scattered by the human eye tissue, the ballistic photons and the serpentine photons return along the original path after reflection, and the returned first reflected light beam and the second reflected light beam are still in mutually orthogonal polarization states. That is to say, the scanning beam for measuring and imaging the eye is emitted between the first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 of the dual-mode polarized optical coherent imaging system and received by The reflected light beams formed by the reflection of the eyes are all in orthogonal polarization states. Therefore, the scanning beams emitted by the first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 and the received reflected light beams will not interact with each other. Crosstalk occurs between them, and the two are a pair of mutually coupled imaging systems.

In other words, the dual-mode polarized optical coherent imaging system utilizes orthogonal polarized light measurement, so that the scanning beams emitted by the first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 and received The reflected beams will not produce crosstalk with each other, and because there is very little polarized light in the natural environment, the interference of stray light in the working process can be avoided, so the measurement result of the dual-mode polarized optical coherent imaging system has a high signal-to-noise ratio, High detection accuracy.

It can also be understood that the first polarization optical coherence imaging system 100 of the dual-mode polarization optical coherence imaging system has the advantages of high-precision imaging provided by the spectral domain optical coherence tomography technology, and the second polarization optical coherence imaging system has the advantage of high precision imaging. The imaging system 101 has the advantages of fast scanning speed, large scanning depth, high signal-to-noise ratio of collected signals, and depth imaging of the swept-frequency optical coherence tomography technology. Accurate human eye structure imaging to meet the detection needs of existing cataract surgery.

In addition, by combining the orthogonal polarization measurement method, spectral domain optical coherence tomography technology and swept-frequency optical coherence tomography technology, the stringent requirements for single-mode fiber dispersion performance and dichroic mirror coating performance in common optical path measurement can be reduced In this way, it is beneficial to reduce the difficulty of constructing the overall optical path of the dual-mode polarization optical coherent imaging system, so that the overall optical path structure of the dual-mode polarization optical coherent imaging system is simple in structure, easy to implement, and low in construction cost.

It is worth mentioning that the central processing unit 16 is a computer.

As shown in FIG. 2 , the specific optical path structure of the first polarized optical coherent imaging system 100 is illustrated. Specifically, the first polarized optical coherent imaging system 100 includes a broadband light source 1 connected by an optical fiber, a first optical fiber coupler 2 , a first collimating lens 4 , a dispersion compensator 5 , a second focusing lens 6 , and a reflecting mirror 7 and the spectrometer 3 and the second collimating lens 9 connected to the first fiber coupler 2 through optical fibers, wherein the broadband light beam emitted by the broadband light source 1 is divided into a broadband reference beam and a broadband reference beam through the first fiber coupler 2 Broadband scanning beam, the broadband reference beam is sequentially transmitted to the first collimating lens 4, the dispersion compensator 5, the second focusing lens 6 and the reflecting mirror 7 through the optical fiber to form a reflected broadband reference beam, The broadband scanning beam passes through the second collimating lens 9 to form a broadband scanning parallel beam, and the broadband scanning parallel beam is transmitted to the polarization beam splitter cube 10 to obtain the first reflected beam. The beam and the reflected broadband reference beam are transmitted to the first fiber coupler 2 for coherence to generate the first coherent light, and the first coherent light is transmitted to the spectrometer 3 for spectral analysis.

It should be understood that, the scanning beam sent by the first polarized optical coherent imaging system 100 and input into the polarization beam splitter cube 10 refers to the broadband scanning parallel beam.

It is worth mentioning that the center wavelength of the broadband light source 1 is 840 nm.

More specifically, as shown in FIG. 3 , the spectrometer 3 includes a third collimating lens 31 , a reflective grating 32 , a transmissive grating 33 , a cylindrical lens 34 and a line scan camera 35 , which are sequentially connected by optical fibers, wherein the The first coherent light is incident on the third collimating lens 31 to form parallel coherent light, and the parallel coherent light is incident on the reflective grating 32 for first-order splitting to obtain a first-order split beam. The split beam is incident on the transmission grating 33 for secondary splitting to obtain a secondary split beam, and the secondary split beam is focused on the line scan camera 35 through the cylindrical lens 34 to obtain interference spectrum information, Finally, it is transmitted to the central processing unit 16 for data analysis, and then transmitted to the data register 17 for data storage.

It is worth mentioning that the first polarized optical coherent imaging system 100 further includes a linear displacement platform 8, the mirror 7 is disposed on the linear displacement platform 8, and the linear displacement platform 8 is driven by a voice coil motor to move. , used to adjust the distance between the mirror 7 and the second focusing lens 6 .

It can be understood that, since the effective detection depth of the spectral domain optical coherence tomography detection technology in the prior art is about 3 mm, which is not enough to cover the detection of the entire lens and the anterior and posterior capsules of about 8 mm, the first polarization of the present invention The optical coherent imaging system 100 uses a voice coil motor to drive the linear displacement platform 8 to realize an imaging detection module with variable detection depth, so as to meet the requirements of the dual-mode polarization optical coherent imaging system for large-scale scanning imaging.

It can also be understood that, on the one hand, the dual-mode polarization optical coherent imaging system utilizes the high-speed dynamic response capability of the voice coil motor to compensate for the measurement error caused by the vibration of the human eye along the optical axis; on the other hand, The dual-mode polarized optical coherent imaging system uses a voice coil motor to drive the linear displacement platform 8 to move in one dimension, so as to complete the axial translation of the detection range.

As shown in FIG. 4 , the specific optical path structure of the second polarized optical coherent imaging system 101 is clarified. 26, the third fiber coupler 25, the fiber polarizer assembly 29, the beam expander assembly 21, the parallel reflector assembly 20, the frequency shifter 22, the balanced detector 23, the high-speed acquisition card 24, the scan trigger 28, and the first Four collimating lenses 18, the fiber polarizer assembly 29 includes a first fiber polarizer and a second fiber polarizer, and the beam expander assembly 21 includes a first beam expander and a second beam expander, so The parallel reflector assembly 20 includes a first parallel reflector and a second parallel emitter, wherein the light beam emitted by the frequency swept light source 27 is divided into a first light beam and a second light beam by the second fiber coupler 26, so The first beam is transmitted to the scan trigger 28 through an optical fiber, and the second beam is divided into a frequency-sweep reference beam and a frequency-sweep scan beam through the third fiber coupler 25, and the frequency-sweep reference beam is sequentially transmitted to The first optical fiber polarizer and the first beam expander are reflected by the first parallel reflector and the second parallel reflector to form a reflective frequency sweep reference beam, and the reflected frequency sweep reference beam is transmitted in sequence After reaching the second beam expander, the frequency shifter 22 and the second fiber polarizer, it is transmitted to the balanced detector 23 , and the frequency sweeping beam is formed by the fourth collimating lens 18 The swept frequency scan parallel beam is transmitted to the polarization beam splitter cube 10 to obtain the second reflected beam, the second reflected beam and the reflected frequency swept reference beam are transmitted to the balance Heterodyne detection processing is performed in the detector 23 , and finally transmitted to the high-speed acquisition card 24 and the central processing unit 16 in sequence.

It should be understood that, the scanning beam sent by the second polarized optical coherent imaging system 101 and input into the polarization beam splitter cube 10 refers to the scanning parallel beam.

It is worth mentioning that the center wavelength of the frequency sweep light source 27 is 1310 nm.

It can be understood that, because the second polarization optical coherence imaging system 101 has the characteristics of large detection depth and fast scanning speed of the swept-frequency optical coherence tomography technology, the swept-frequency optical coherence tomography technology can detect the key points of the human eye. Position point data, in order to facilitate the rapid reconstruction of the three-dimensional structure model of the human eye, and realize the real-time tracking of the spatial pose of the human eye.

It can also be understood that the second reflected beam and the reflected frequency sweep reference beam are transmitted to the balance detector 23 for heterodyne detection processing, which can avoid being affected by environmental temperature, humidity, vibration and other factors. background noise effects.

It is worth mentioning that the second polarized optical coherent imaging system 101 adopts the frequency shifter 22 to extend the imaging depth, and can realize the imaging of the entire human anterior segment from the top surface of the cornea to the posterior capsule of the lens.

More specifically, as shown in FIG. 5 , the scan trigger 28 includes a photodetector 281, a fiber circulator 282 and a fiber Bragg grating 283 connected in sequence through an optical fiber, and the fiber Bragg grating 283 is used to generate a stable phase. Sweep the trigger signal to remove fixed pattern noise.

It is worth mentioning that, in this preferred embodiment of the present invention, the scan trigger 28 is an A-scan trigger, and the fiber Bragg grating 283 is used to generate a stable phase A-scan trigger signal to Replaces the A-scan trigger signal in the signal source, thereby eliminating fixed pattern noise.

In addition, it is also worth mentioning that the dual-mode polarization optical coherent imaging system further includes a high-speed camera 12, and the high-speed camera 12 is connected to the data register 17 through an electrical signal path and is connected to the first optical fiber through an optical fiber. Channel 13 is used to present the image of the target imaging area in real time.

It can be understood that the dual-mode polarized optical coherent imaging system can be observed in real time during the process of imaging the structure of the human eye. When the dual-mode polarized optical coherent imaging system is used to assist femtosecond laser cataract surgery, the doctor can observe the patient's surgical process in real time through the high-speed camera 12 , and the dual-mode polarized optical coherent imaging system images the human eye structure in real time, which can At the same time, the imaging of the three-dimensional model of the human eye structure and the observation of the surgical implementation process were completed.

As shown in FIG. 6 , in another aspect, the present invention also provides an imaging method of a dual-mode polarization optical coherent imaging system, comprising the following steps:

A. The scanning beams emitted by the first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 are transmitted to the polarization beam splitter cube 10 for modulation to form two mutually orthogonal polarized beams. The polarization beam splitter cube 10 combines two mutually orthogonal polarized lights and outputs the first combined beam;

B. The first combined beam is transmitted to the scanning galvanometer 11 and the first optical channel 13 in turn, and the beam is split in the first optical channel 13, and the split beam enters the second optical channel 14 after being reflected and then enters the second optical channel 14 again. performing beam combining in the first optical channel 13 to output the second combined beam;

C. The second combined beam is focused on the target imaging area by the first focusing lens 15, the second combined beam is reflected by the target imaging area to form a reflected beam, and the reflected beam is polarized by the polarization splitter The beam cube 10 performs beam splitting to form a first reflected beam and a second reflected beam;

D. The first reflected beam is transmitted back to the first polarized optical coherent imaging system 100 for coherence with the corresponding reflected broadband reference beam to generate first coherent light, which is transmitted to the first coherent light after spectral analysis Central processing unit 16;

E. The second reflected beam is transmitted back to the second polarized optical coherent imaging system 101 and the corresponding reflected frequency sweep reference beam is subjected to heterodyne detection processing and then transmitted to the central processing unit 16;

F. After the central processing unit 16 performs data analysis, the analysis result is transmitted to the data register 17 for storage.

Specifically, the step D specifically includes the steps:

D1. The broadband light beam emitted by the broadband light source 1 is divided into a broadband reference beam and a broadband scanning beam by the first fiber coupler 2;

D2. The broadband reference beam is sequentially transmitted to the first collimating lens 4, the dispersion compensator 5, the second focusing lens 6 and the reflecting mirror 7 through the optical fiber to form a reflected broadband reference beam;

D3. The broadband scanning beam passes through the second collimating lens 9 to form a broadband scanning parallel beam, and the broadband scanning parallel beam is transmitted to the polarization beam splitter cube 10 to obtain the first reflected beam;

D4. The first reflected beam and the reflected broadband reference beam are transmitted to the first fiber coupler 2 for coherence to generate the first coherent light, and the first coherent light is transmitted to the spectrometer 3 for spectroscopy analyze.

More specifically, in the step D4, the specific steps of performing spectral analysis on the first coherent light are:

D41. The first coherent light is incident on the third collimating lens 31 of the spectrometer 3 to form parallel coherent light;

D42, the parallel coherent light is incident on the reflection grating 32 of the spectrometer 3 to perform first-order splitting to obtain a first-order split beam;

D43, the first-order split beam is incident on the transmission grating 33 of the spectrometer 3 to perform second-order splitting to obtain a second-order split beam;

D44 , the secondary beam splitting beam is focused into the line scan camera 35 of the spectrometer 3 through the cylindrical lens 34 of the spectrometer 3 to obtain interference spectrum information.

Further, described step E specifically comprises steps:

E1, the light beam emitted by the frequency sweep light source 27 is divided into a first light beam and a second light beam by the second fiber coupler 26;

E2, the first light beam is transmitted to the scanning trigger 28 through the optical fiber;

E3, the second light beam is divided into a frequency-sweeping reference beam and a frequency-sweeping scanning beam through the third fiber coupler 25;

E4. The frequency swept reference beam is transmitted to the first optical fiber polarizer and the first beam expander in turn, and then reflected by the first parallel reflector and the second parallel reflector to form a reflective frequency swept reference beam. The reflective frequency swept reference beam is The light beam is transmitted to the second beam expander, the frequency shifter 22, and the second optical fiber polarizer in sequence, and then transmitted to the balanced detector 23;

E5. The swept-frequency scanning beam is passed through the fourth collimating lens 18 to form a swept-frequency scanning parallel beam, and the swept-frequency scanning parallel beam is transmitted to the polarization beam splitter cube 10 to obtain the second reflected beam;

E6. The second reflected beam and the reflected frequency sweep reference beam are transmitted to the balanced detector 23 for heterodyne detection processing, and finally transmitted to the high-speed acquisition card 24 and the central processing unit 16 in sequence.

The present invention provides a dual-mode polarized optical coherence tomography imaging system and an imaging method thereof. The first polarized optical coherent imaging system 100 and the second polarized optical coherent imaging system 101 are polarized by using the polarized light detection technology. The beam splitter cube and the fiber polarizer assembly construct a pair of orthogonally polarized light structures, which do not crosstalk each other during detection and are not easily interfered by stray light. Moreover, the second polarization optical coherent imaging system 101 has the characteristics of fast scanning speed and large scanning depth to roughly measure the structure of the human eye and lock the region of interest, and then the first polarization optical coherent imaging system 100 realizes the concern The high-resolution imaging of the area solves the problem that the existing technology cannot take into account the large-scale and high-precision human eye structure imaging. It can simultaneously realize large-scale and high-precision human eye structure measurement, and meet the detection requirements of femtosecond laser cataract surgery. .

The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features It is considered to be the range described in this specification.

The above examples only represent the preferred embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (12)

1. a dual-mode polarized optical coherent imaging system, is characterized in that, comprises the first polarized optical coherent imaging system, the second polarized optical coherent imaging system, central processing unit and data register connected by electrical signal path, and is connected by optical fiber The polarization beam splitter cube, scanning galvanometer, first optical channel, second optical channel and first focusing lens; the first polarization optical coherent imaging system and the second polarization optical coherent imaging system are respectively connected to the the polarizing beam splitter cube; Wherein, the scanning beams emitted by the first polarized optical coherent imaging system and the second polarized optical coherent imaging system are input into the polarized beam splitter cube for modulation to form two mutually orthogonal polarized beams, and the polarized beam splitter The beam cube combines the two orthogonal polarized lights and outputs the first combined light, and the first combined light is transmitted to the scanning galvanometer and the first optical channel in turn. Light splitting is performed in the optical channel, and the split light beam enters the second optical channel for reflection and then enters the first optical channel for beam combining to output a second combined beam light, and the second combined beam light passes through the The first focusing lens focuses on the target imaging area, the second combined beam is reflected by the target imaging area to form a reflected beam, and the reflected beam is split by the polarization beam splitter cube to form a first reflected beam and a second beam. Two reflected beams, the first reflected beam is transmitted back to the first polarized optical coherent imaging system for coherence with the corresponding reflected broadband reference beam to generate first coherent light, and the first coherent light is transmitted to the The central processing unit, the second reflected beam is transmitted back to the second polarized optical coherent imaging system and the corresponding reflected frequency sweep reference beam is subjected to heterodyne detection processing and then transmitted to the central processing unit, and the central processing unit performs a heterodyne detection process. After data analysis, the analysis result is transferred to the data register for saving. 2 . The dual-mode polarization optical coherent imaging system according to claim 1 , wherein the first reflected light beam and the second reflected light beam are in orthogonal polarization states. 3 . 3. The dual-mode polarized optical coherent imaging system according to claim 2, wherein the first polarized optical coherent imaging system comprises a broadband light source connected by an optical fiber, a first optical fiber coupler, a first collimating lens, A dispersion compensator, a second focusing lens, a mirror, a spectrometer and a second collimating lens connected to the first fiber coupler through an optical fiber, wherein the broadband light beam emitted by the broadband light source passes through the first fiber coupler It is divided into a broadband reference beam and a broadband scanning beam. The broadband reference beam is sequentially transmitted to the first collimating lens, the dispersion compensator, the second focusing lens and the reflecting mirror through an optical fiber to form a reflective broadband reference beam. The broadband scanning beam passes through the second collimating lens to form a broadband scanning parallel beam, and the broadband scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the first reflected beam, the first reflected beam The beam and the reflected broadband reference beam are transmitted into the first fiber coupler for coherence to generate the first coherent light, and the first coherent light is transmitted to the spectrometer for spectral analysis. 4 . The dual-mode polarization optical coherent imaging system according to claim 3 , wherein the spectrometer comprises a third collimating lens, a reflection grating, a transmission grating, a cylindrical lens and a linear array sequentially connected by an optical fiber. 5 . A scanning camera, wherein the first coherent light is incident on the third collimating lens to form parallel coherent light, and the parallel coherent light is incident on the reflective grating to perform first-order beam splitting to obtain a first-order beam, so The first-order split beam is incident on the transmission grating for second-order splitting to obtain a second-order split beam, and the second-order split beam is focused into the line scan camera through the cylindrical lens to obtain interference spectrum information. 5. The dual-mode polarized optical coherent imaging system according to claim 3, wherein the first polarized optical coherent imaging system further comprises a linear displacement platform, and the reflector is arranged on the linear displacement platform, so that the The linear displacement platform is driven and moved by a voice coil motor, and is used for adjusting the distance between the reflecting mirror and the second focusing lens. 6. The dual-mode polarized optical coherent imaging system according to any one of claims 1 to 5, wherein the second polarized optical coherent imaging system comprises a frequency swept light source connected by an optical fiber, a second optical fiber coupler , a third fiber coupler, a fiber polarizer assembly, a beam expander assembly, a parallel reflector assembly, a frequency shifter, a balanced detector, a high-speed acquisition card, a scan trigger, and a fourth collimating lens, the fiber polarizer The beam expander assembly includes a first fiber polarizer and a second fiber polarizer, the beam expander assembly includes a first beam expander and a second beam expander, and the parallel reflector assembly includes a first parallel reflector and a second beam expander. Two parallel transmitters, wherein the light beam emitted by the frequency-sweeping light source is divided into a first light beam and a second light beam by the second fiber coupler, the first light beam is transmitted to the scanning trigger through an optical fiber, and the The second beam is divided into a frequency swept reference beam and a frequency swept scan beam by the third fiber coupler. The frequency swept reference beam is sequentially transmitted to the first fiber polarizer, the first beam expander and then passed The first parallel reflector and the second parallel reflector are reflected to form a reflected frequency sweep reference beam, and the reflected frequency sweep reference beam is sequentially transmitted to the second beam expander, the frequency shifter, and the first beam. The two fiber polarizers are then transmitted to the balanced detector. The swept-frequency scanning beam passes through the fourth collimating lens to form a swept-frequency scanning parallel beam, and the swept-frequency scanning parallel beam is transmitted to the polarization beam splitter cube. In order to obtain the second reflected beam, the second reflected beam and the reflected frequency sweep reference beam are transmitted to the balanced detector for heterodyne detection processing, and finally transmitted to the high-speed acquisition card and the central processing unit. 7. The dual-mode polarization optical coherent imaging system according to claim 6, wherein the scanning trigger comprises a photodetector, a fiber circulator, and a fiber Bragg grating sequentially connected by an optical fiber, and the fiber Bragg grating uses It is used to generate a stable phase sweep trigger signal to eliminate fixed pattern noise. 8. The dual-mode polarization optical coherent imaging system according to claim 7, wherein the dual-mode polarization optical coherent imaging system further comprises a high-speed camera, the high-speed camera is connected to the data register through an electrical signal path and It is connected to the first optical channel through an optical fiber, and is used for presenting the image of the target imaging area in real time. 9. An imaging method for a dual-mode polarization optical coherent imaging system, characterized in that, comprising the following steps: A. The scanning beams emitted by the first polarized optical coherent imaging system and the second polarized optical coherent imaging system are transmitted to the polarized beam splitter cube for modulation to form two mutually orthogonal polarized lights, and the polarized beam splitter cube will be mutually orthogonal to each other. The crossed two polarized beams are combined and the first combined beam is output; B. The first combined beam is transmitted to the scanning galvanometer and the first optical channel in turn, and the beam is split in the first optical channel. The split beam enters the second optical channel for reflection and then enters the first optical channel again. Combining beams is performed in the channel to output the second beam combining light; C. The second combined beam is focused to the target imaging area by the first focusing lens, the second combined beam is reflected by the target imaging area to form a reflected beam, and the reflected beam is processed by the polarization beam splitter cube. splitting to form a first reflected beam and a second reflected beam; D. The first reflected beam is transmitted back to the first polarized optical coherent imaging system for coherence with the corresponding reflected broadband reference beam to generate first coherent light, which is transmitted to the central processing unit after spectral analysis ; E. The second reflected beam is transmitted back to the second polarized optical coherent imaging system and the corresponding reflected frequency swept reference beam is subjected to heterodyne detection processing and then transmitted to the central processing unit; F. After the central processing unit performs data analysis, the analysis result is transmitted to the data register for storage. 10. The method according to claim 9, wherein the step D specifically comprises the steps: D1. The broadband light beam emitted by the broadband light source is divided into a broadband reference beam and a broadband scanning beam through the first fiber coupler; D2. The broadband reference beam is sequentially transmitted to the first collimating lens, the dispersion compensator, the second focusing lens and the reflecting mirror through the optical fiber to form a reflected broadband reference beam; D3. The broadband scanning beam passes through the second collimating lens to form a broadband scanning parallel beam, and the broadband scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the first reflected beam; D4. The first reflected beam and the reflected broadband reference beam are transmitted to the first fiber coupler for coherence to generate the first coherent light, and the first coherent light is transmitted to a spectrometer for spectral analysis. 11. The method according to claim 10, wherein, in the step D4, the specific step of performing spectral analysis on the first coherent light is: D41. The first coherent light is incident on the third collimating lens of the spectrometer to form parallel coherent light; D42, the parallel coherent light is incident on the reflection grating of the spectrometer to perform first-order splitting to obtain a first-order split beam; D43. The first-order split beam is incident on the transmission grating of the spectrometer to perform second-order splitting to obtain a second-order split beam; D44. The second-order split light beam is focused into the line scan camera of the spectrometer through the cylindrical lens of the spectrometer to obtain interference spectrum information. 12. according to the method described in any one of claim 9-11, it is characterised in that described step E specifically comprises step: E1. The light beam emitted by the frequency swept light source is divided into a first light beam and a second light beam by the second fiber coupler; E2, the first light beam is transmitted to the scanning trigger through the optical fiber; E3. The second light beam is divided into a frequency-sweeping reference beam and a frequency-sweeping scanning beam through the third fiber coupler; E4. The frequency swept reference beam is transmitted to the first optical fiber polarizer and the first beam expander in turn, and then reflected by the first parallel reflector and the second parallel reflector to form a reflective frequency swept reference beam. The reflected frequency swept reference beam is The light beam is sequentially transmitted to the second beam expander, the frequency shifter, and the second optical fiber polarizer, and then transmitted to the balanced detector; E5. The swept-frequency scanning beam is formed by a fourth collimating lens to form a swept-frequency scanning parallel beam, and the swept-frequency scanning parallel beam is transmitted to the polarization beam splitter cube to obtain the second reflected beam; E6. The second reflected beam and the reflected frequency sweep reference beam are transmitted to the balanced detector for heterodyne detection processing, and finally transmitted to the high-speed acquisition card and the central processing unit in sequence.

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