Dispersion-optimized parallel optical computing OCT (optical coherence tomography) system

Abstract

The invention belongs to the field of biomedical photonics, and particularly relates to a dispersion-optimized parallel optical computing OCT (optical coherence tomography) system. According to the invention, a parallel optical calculation method is adopted to break through the bottleneck of spectral data processing speed of an electronic computer, and sample structure information is obtained by using all-optical real-time fractional order Fourier transform operation, so that high-speed imaging is realized; in the aspect of imaging quality, a dispersion optimization mechanism is introduced, so that the reduction of imaging resolution caused by a parallel light calculation process is effectively compensated, and conjugate complex components of spectral signals are inhibited. According to the method, the imaging quality is improved while high-speed imaging is realized, the problem of balancing the imaging speed and the resolution of the conventional optical calculation OCT is solved, the method is related to the fields of clinical medical imaging and optics, and a solution is provided for clinical autonomous application of OCT.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical photonics, and more particularly, relates to a dispersion-optimized parallel optical computing (OCT) system. Background Art

[0002] Optical coherence tomography (OCT) is a non-invasive, high-resolution tomographic imaging technology. The working principle of OCT is based on the Michelson interferometer, which uses broadband light emitted by a broadband light source to analyze the fine structural information deep in the sample through the interference spectrum output by the interferometer. In recent years, thanks to the progress of light sources, detectors, optical components and signal processing technology, OCT has shown great application potential and has been widely used in clinical medicine fields such as skin disease diagnosis and early cancer screening. With the expansion of the scope of application and the increase in application demand, imaging speed and resolution have become the main bottlenecks restricting the further development of OCT technology. Ultra-high imaging speed can significantly shorten the imaging time, which is of great significance for capturing the occurrence of clinical transient and non-repetitive events. It is particularly suitable for real-time detection of dynamic tissues (heart, blood vessels). High-resolution imaging quality can improve the system's ability to identify the microstructure of the sample, providing a guarantee for precision medical diagnosis and treatment.

[0003] Optical computing is an emerging technology that uses optical methods for data processing and calculation. Optical computing OCT introduces optical computing units (dispersion prisms, optical fibers, spatial modulators, etc.) into the signal processing chain to implement operations such as signal conversion, filtering, and compression in the spectral domain. Compared with traditional OCT, optical computing OCT breaks through the bottleneck of interference signals relying on electronic computing processing, making the computing speed no longer restricted by the bandwidth, power consumption, and delay of electronic components, significantly improving the signal processing speed and making real-time high-speed imaging possible.

[0004] Although the application of OCT technology in the field of biomedical imaging has made significant progress in recent years, there are still certain limitations in imaging speed and quality, which makes it difficult to meet high-demand application scenarios.

[0005] In terms of imaging speed, traditional OCT faces the following technical problems:

[0006] In traditional OCT, the processing speed of interference signals is limited by the hardware performance of the electronic computing system. This is especially true for frequency-domain OCT (FD-OCT), where the Fourier transform of the interference signal and the subsequent image reconstruction process require a large amount of computing resources. Furthermore, the development of existing high-performance electronic computing systems is limited, and further increases in their computing speed are limited by physical principles. As transistor sizes continue to shrink, approaching the atomic scale, quantum effects are beginning to significantly affect the normal operation of transistors. For example, quantum tunneling can cause leakage problems, thereby affecting the stability and reliability of transistors.

[0007] Although the application of traditional optical computing OCT solves the technical problem of high-speed real-time processing of spectral big data, it is seriously restricted in terms of imaging quality. In terms of imaging quality, traditional optical computing OCT faces the following technical problems:

[0008] In principle, optical computing systems can only perform fractional Fourier transforms on spectra, not Fourier transforms. Therefore, to achieve high-speed optical computing-based spectral processing, conventional optical computing OCT must use fractional Fourier transforms to approximate the Fourier transform process used in FD-OCT. Due to the errors introduced by mathematical approximation, the A-scan images approximated by fractional Fourier transforms experience significant degradation in resolution and signal-to-noise ratio. This degraded longitudinal resolution severely limits the application prospects of conventional optical computing OCT. Summary of the Invention

[0009] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and propose a dispersion-optimized parallel optical computing OCT system.

[0010] The technical solution of the present invention is:

[0011] A dispersion-optimized parallel optical computing OCT system, comprising a light source, an interferometer unit, a dispersion optimization unit, and a parallel optical computing unit;

[0012] The light source is used to generate parallel broadband light and transmit it to the interferometer unit;

[0013] The interferometer unit is used to receive the parallel broadband light generated by the light source and divide the broadband light into two paths: reference light and sample light, wherein the reference light is reflected by the reference mirror via the dispersion optimization unit, and the sample light is reflected by the sample;

[0014] The two returning lights then meet and interfere, generating dispersion-optimized interference light, which is then output to a parallel optical computing unit.

[0015] The dispersion optimization unit is used to perform specific dispersion modulation on the reference light, thereby performing dispersion optimization on the interference spectrum;

[0016] The parallel optical computing unit is used to spatially modulate the input optical signal and then complete the spatial mapping and superposition summation of the spectral signal. This process is called optical computing, and the optical computing results are then collected and displayed.

[0017] The interferometer unit includes a beam splitter, a reference mirror, and a sample. The beam splitter is used to split the incident light into two beams: reference light and sample light. The reference mirror is used to return the reference light along its original path. The sample is used to return the sample light along its original path by reflection or backscattering. The reference light is dispersion-modulated by the dispersion optimization unit and then interferes with the sample light, forming interference light that is transmitted to the parallel optical computing unit.

[0018] The interferometer unit includes a beam splitter prism, two cylindrical mirrors, a reference mirror, and a sample.

[0019] The parallel broadband light generated by the light source is output to the beam splitter prism, where it is then split into two paths. One path enters the reference arm, passes through a dispersion optimization unit and a cylindrical mirror, and converges onto a line on the reference mirror. The reflected reference light then returns along the original path. The other path enters the sample arm, passes through a cylindrical mirror, and converges onto a line on the sample. It then returns along the original path, carrying information about the sample structure, as the sample light. The reference light is dispersion-modulated by the dispersion optimization unit and interferes with the sample light, forming interference light that is transmitted to the parallel optical computing unit.

[0020] The dispersion optimization unit includes a dispersion optimization mechanism and a dispersion element.

[0021] The dispersion optimization mechanism obtains the optimal dispersion optimization amount based on the system parameters, and further determines the dispersion amount of the dispersion element.

[0022] The dispersion element is used to perform dispersion modulation on the reference spectrum. The dispersion-modulated reference light interferes with the sample light carrying the sample structure information and is then output to the parallel optical computing unit. The dispersion element in the dispersion optimization unit can be a dispersion glass plate, which determines the dispersion amount based on the dispersion optimization mechanism and is used to dispersion modulate the reference light. In this case, the modulation signal applied to the spectral signal output by the interferometer is a linear frequency modulation signal. The expression for the thickness of the dispersion glass bottle and the dispersion amount it introduces in the interferometer is as follows:

[0023] ΔD=2D glass d

[0024] Among them, D glass is the dispersion per unit thickness of the dispersive glass, and d is the glass thickness. Because the reference light travels back and forth twice through the dispersive glass, the coefficient 2 is included in equation (1). The material and thickness of the dispersive glass are selected based on the value ΔD, determined by the need to introduce the optimal dispersion between the two arms, as assessed by the dispersion optimization mechanism.

[0025] The dispersion optimization unit includes a dispersion optimization mechanism and a dispersion optimization method. The dispersion optimization mechanism is used to evaluate the amount of dispersion that needs to be introduced between the two arms. The dispersion optimization method controls the incident angle of the light beam incident to the beam splitter prism, the angle of the reference mirror and the sample, so as to introduce a predetermined dispersion difference between the reference arm and the sample arm.

[0026] The dispersion optimization method enables the light beam to pass through glass materials of different thicknesses in the two arms, thereby generating different group velocity dispersions, thereby achieving an effect equivalent to introducing a dispersion element in the reference arm.

[0027] The incident angle of the light beam, the angle of the reference mirror and the sample are adjustable to achieve flexible control and optimization of the dispersion amount.

[0028] The inclination angle θ of the incident light beam 10 , the inclination angle θ of the reference mirror 4 40 , the inclination angle θ of the sample 5 30 As an optimization condition, the group velocity dispersion coefficient D of the beam splitter prism 2 is glass , refractive index n and side length h as known conditions, the calculation formula of the equivalent dispersion ΔD introduced is as follows:

[0029]

[0030] The angle in the formula is selected based on the value ΔD determined by the need to introduce an optimal amount of dispersion between the two arms as assessed by the dispersion optimization mechanism.

[0031] The dispersion optimization mechanism includes:

[0032] Obtain various system parameters, including the spatial template modulation coefficient a, the dispersion element angular dispersion rate D k The distance L between the dispersion element and the area array camera is a known condition.

[0033] The optimal dispersion ΔD is calculated based on various system parameters. The formula for calculating the optimal dispersion ΔD between the two arms of the interferometer is as follows:

[0034]

[0035] The parallel optical computing unit includes a two-dimensional space template, a dispersion element, an area array camera and a computer;

[0036] The two-dimensional spatial template is used to perform two-dimensional spatial modulation on the interference signal, and transmit the modulated spectrum signal to the dispersion element;

[0037] The dispersion element is used to map the modulated spectrum signal from the wavenumber domain to the spatial domain, and complete the superposition and summation, complete the optical calculation, and then transmit the result of the optical calculation to the area array camera and the computer;

[0038] The area array camera is used to collect light intensity signals and transmit them to a computer.

[0039] The computer is used to collect and display the results of optical calculations, that is, sample structure information.

[0040] When the system is used to obtain sample structure information in OCT, the spatial transmittance of the two-dimensional space template is a linear frequency modulation signal (ie, cos(ax 2 )), where a is a constant and x is the spatial coordinate.

[0041] The dispersive element of the parallel optical computing unit can be an equilateral dispersive prism, a reflective grating, or a transmissive grating. It is used to provide dispersion for optical signals. Mathematically, this can be viewed as first constructing a mapping relationship from the wavenumber domain to the spatial domain for the input optical signal, and then outputting the convolution of the spectral signal with a two-dimensional template function at a specific location. When the dispersive element is an equilateral dispersive prism, the incident light path can meet the minimum deflection angle condition.

[0042] Beneficial effects

[0043] The system of the present invention utilizes a dispersive element and a two-dimensional spatial template, combined with OCT interferometric signals, to achieve improved system resolution and signal-to-noise ratio. A dispersion optimization method is introduced. This method controls the incident angle of the light beam incident on the beam splitter prism and the angles of the reference mirror and sample to introduce a predetermined dispersion difference between the reference and sample arms. The required dispersion amount of the dispersive glass 3 is determined based on system parameters. This effectively addresses the output image signal broadening and resolution degradation caused by the approximate Fourier transform in conventional optical computed optical coherence tomography (OCT). The system also suppresses the conjugate complex signal of the output signal, improving the resolution and imaging quality of optical computed optical coherence tomography (OCT). Dispersive glass is added to the optical path to introduce a predetermined dispersion difference between the reference and sample arms. The predetermined dispersion difference is introduced between the reference and sample arms by controlling the incident angle of the light beam incident on the beam splitter prism and the angles of the reference mirror and sample. A method for calculating the optimal dispersion amount, i.e., the dispersion optimization mechanism, is provided. This dispersion is then determined, improving the imaging resolution and quality of optical computed optical coherence tomography (OCT), resulting in improved imaging performance compared to conventional optical computed optical coherence tomography (OCT).

[0044] The present invention proposes a dispersion-optimized parallel optical computing OCT system, which belongs to the field of optical computing and biomedical photonics, and particularly relates to its application in OCT imaging systems. In terms of imaging speed, the present invention uses a parallel optical computing method to break through the bottleneck of the spectral data processing speed of electronic computers, and uses all-optical real-time fractional Fourier transform operations to obtain sample structure information, thereby achieving high-speed imaging. In terms of imaging quality, by introducing a dispersion optimization mechanism, the reduction in imaging resolution caused by the parallel optical computing process is effectively compensated, and the conjugate complex components of the spectral signal are suppressed. The present invention improves imaging quality while achieving high-speed imaging, solving the trade-off problem between imaging speed and resolution in traditional optical computing OCT. The present invention is related to the fields of clinical medical imaging and optics, and provides a solution for the autonomous clinical application of OCT. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the solution of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1a A schematic diagram of a system of the present invention including a dispersion glass;

[0047] Figure 1b A schematic diagram of the system of the present invention without dispersive glass;

[0048] Figure 2 This is a flow chart of a dispersion optimization mechanism according to an embodiment of the present application;

[0049] Figure 3 for Figure 2 Supplementary illustration of a dispersion optimization mechanism without the need for a dispersion element;

[0050] Figure 4 Shown Figure 3 The result diagram of the equivalent dispersion introduced without dispersion elements;

[0051] Figure 5 This is a result diagram obtained by using a single reflective surface as a sample using non-dispersion-optimized optical computing OCT (i.e., conventional optical computing OCT) according to an embodiment of the present application;

[0052] Figure 6 The results of OCT calculation for a single reflective surface as a sample for light with optimized dispersion are shown.

[0053] Reference numerals: 1 - light source; 2 - beam splitter; 3 - dispersion glass; 4 - reference mirror; 5 - sample; 6 - two-dimensional space template; 7 - dispersion element; 8 - area array camera; 9 - electronic computer. DETAILED DESCRIPTION

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0055] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] Figure 1a The system of the present application includes a schematic diagram of the dispersive glass composition, wherein the black dashed box is a schematic diagram of the parallel spectral calculation unit of the dispersion-optimized optical computing OCT system. The embodiment of the present application provides a dispersion-optimized parallel optical computing OCT system. The dispersion-optimized optical computing OCT system achieves rapid processing of spectral signals based on parallel spectral calculation, with extremely high spectral processing speed. In addition, by introducing a dispersion optimization mechanism to enhance the A-Scan signal intensity and suppress conjugate signal components, the system can output high-resolution sample images with higher imaging quality than traditional optical computing OCT. Figure 1a The dispersion optimized optical computing OCT system is mainly composed of a light source 1, a beam splitter prism 2, a dispersion glass 3, a reference mirror 4, a sample 5, a two-dimensional space template 6, a dispersion element 7, an area array camera 8, and an electronic computer 9.

[0057] See Figure 1a In this embodiment, on an optical platform, light source 1 generates parallel broadband light, which enters beam splitter prism 2. The beam splitting ratio of beam splitter prism 2 can be set to 5:5, 4:6, 3:7, 2:8, or 1:9 as needed. The broadband light is reflected and transmitted on the beam splitting surface of beam splitter prism 2, with the reflected light entering the reference arm and the transmitted light entering the sample arm.

[0058] Furthermore, in this embodiment, the reference arm includes a dispersion glass 3 and a reference mirror 4. The reflected light is emitted vertically through the beam splitter prism 2, passes through the dispersion glass 3, and is vertically incident on the reference mirror 4. It is mirror-reflected on the surface of the reference mirror 4 to form a reference light. The reference light returns along the original path and re-enters the beam splitter prism 2 through the dispersion glass 3. The reference mirror 4, the dispersion glass 3, and the beam splitter prism 2 are coaxially arranged. In particular, the dispersion glass 3 is used to introduce a specific second-order dispersion amount for the reference light. By precisely designing the second-order dispersion amount in the optical path through which the reference light passes, a dispersion optimization mechanism can be implemented, effectively improving the signal strength in the optical calculation result and suppressing the complex conjugate component, thereby outputting an image with high axial resolution.

[0059] Furthermore, in this embodiment, the sample arm comprises a sample 5. Transmitted light is emitted perpendicularly through the beam splitter prism 2, incident on the sample 5, and backscattered on the surface of the sample 5 to form sample light. This light then returns along the original path of the transmitted light and re-enters the beam splitter prism 2. The sample 5 and the beam splitter prism 2 are coaxially positioned.

[0060] Specifically, the optical path lengths from the reference mirror 4 and the sample 5 to the beam splitter prism 2 are denoted as the reference distance and the sample distance, respectively. The difference between the reference distance and the sample distance is the optical path difference. To ensure interference between the sample and reference beams in this embodiment, the optical path difference should be on the micrometer level. Furthermore, the elevation and depression angles of the reference mirror 4 and the sample 5 should be identical.

[0061] Further, see also Figure 1a The black dotted line frame part shows the Figure 1a Schematic diagram of the parallel spectrum calculation unit of the medium dispersion optimized optical computing OCT system. Furthermore, in this embodiment, the parallel spectrum calculation unit includes a two-dimensional spatial template 6, a dispersion element 7, an array camera 8, and an electronic computer 9. The sample light and the reference light return along the original path and re-enter the beam splitter prism 2, where they interfere with each other to form interference light, which exits the beam splitter prism 2 perpendicularly and enters the dispersion element 7 through the two-dimensional spatial template 6. Under the condition of minimum deflection angle, the interference light exits the dispersion element 7 to form output light. The intensity information of the output light is collected by the array camera 8 and transmitted to the electronic computer 9, which visualizes the collection results. Optionally, a cylindrical mirror can be introduced before the reference mirror 4 and the sample 5, respectively, so that the illumination light converges on a line on the reference mirror 4 and the sample 5, and the sample structure on this line is imaged.

[0062] In particular, unlike conventional FD-OCT, the interference light does not need to be Fourier transformed by an electronic computer, but is calculated in the optical domain based on the optical calculation method. Specifically, under the condition of minimum deflection angle, the interference light is mapped from the wavenumber domain to the spatial domain under the dispersion of the dispersion element 7, and then convolved with the two-dimensional spatial template 6 to generate output light, which is then recorded by the area array camera 8. Unlike the point-by-point scanning method of the conventional FD-OCT system, the embodiment can implement a parallel light calculation method. Specifically, by introducing a cylindrical mirror before the reference mirror 4 and the sample 5, the illumination light is converged on a line on the reference mirror 4 and the sample 5. Then, the reference light from different positions of the reference mirror 4 will interfere with the sample light in parallel to form parallel interference light, which is then distributed in parallel on the area array camera 8 through the optical calculation unit. That is, the output light intensity information collected by the area array camera 8 is exactly the B-Scan image of the sample 5. If the area array camera 8 used in this case has a sampling frequency of 20 kHz and 1000 rows of pixels, the parallel spectral calculation method has a computational speed of 20 MHz. The application of the parallel spectral calculation method in this embodiment enables the scientific problems of high-speed real-time processing of spectral big data and capturing transient, non-repetitive, and rare events. Furthermore, this embodiment enables high-speed OCT imaging.

[0063] Figure 2 The figure shows a flow chart of a dispersion optimization mechanism according to an embodiment of the present application. The dispersion optimization mechanism performs dispersion optimization on the reference light spectrum signal of the embodiment, thereby achieving dispersion optimization on the interference light spectrum signal of the embodiment. As a preferred solution, the dispersion optimization mechanism has the following details: the dispersion optimization mechanism uses the modulation coefficient a of the spatial template 6, the angular dispersion rate D of the dispersion element 7, and the dispersion coefficient D of the dispersion element 7. k and the distance L between the dispersion element 7 and the area array camera 8 are used as inputs, and the optimal second-order dispersion of the dispersion glass 3 is calculated according to the following formula:

[0064]

[0065] The dispersion amount of the dispersion glass 3 is set to the optimal second-order dispersion amount calculated by the above formula, thereby completing the dispersion modulation process of the reference light.

[0066] Figure 3 Shown is a supplementary illustration of a dispersion optimization mechanism without a dispersion element according to an embodiment of the present application.

[0067] like Figure 1bAs shown, the dispersion glass 3 is not necessarily configured in this embodiment. By reasonably designing the incident angle of the light beam when it is incident on the beam splitter prism 2, the inclination angle of the reference mirror 4 and the inclination angle of the sample 5, the expected optical path difference and dispersion difference can be introduced between the reference arm and the sample arm of the interferometer unit. Specifically, under different incident angles, the propagation path of the light beam inside the beam splitter prism 2 will pass through glass media of different thicknesses, resulting in the two beams of light carrying different group velocity dispersion characteristics after passing through different arms. This method based on geometric optical path control is equivalent to introducing a dispersion compensation device in one arm of the interferometer unit, realizing quantitative control and optimization of dispersion mismatch. This solution is suitable for dispersion adjustment needs when no additional dispersion device is required. As a preferred solution, this solution has the following details: the inclination angle θ of the incident light beam 10 , the inclination angle θ of the reference mirror 4 40 , the inclination angle θ of the sample 5 30 As an optimization condition, the group velocity dispersion coefficient D of the beam splitter prism 2 is glass , refractive index n, and side length d are given as known conditions, and the second-order dispersion introduced by the equivalent dispersion compensation device is calculated according to the following formula:

[0068]

[0069] Obtain the inclination angle θ of the incident beam that satisfies the optimal dispersion compensation amount of the current system 10 , the inclination angle θ of the reference mirror 4 40 , the inclination angle θ of the sample 5 30 Optimization constraint requirements.

[0070] In particular, the optimal second-order dispersion generated by the dispersion optimization mechanism is decoupled from the spectral information of the dispersion optimization optical computing OCT system. In other words, unlike traditional dispersion compensation strategies, the dispersion optimization mechanism proposed in this embodiment can complete the dispersion optimization design process without prior interference spectral information. The optimal dispersion involved in the system is only related to the modulation coefficient a of the spatial template 6, the angular dispersion rate D of the dispersion element 7, and the dispersion coefficient D of the dispersion element 7. k It is related to the distance L between the dispersive element 7 and the area array camera 8 .

[0071] In order to verify the effect of the dispersion optimization mechanism on introducing equivalent dispersion without the dispersion glass 3, an experiment was conducted: without using the dispersion glass 3, the inclination angle θ of the incident light beam was adjusted. 10 , the inclination angle θ of the reference mirror 4 40 , the inclination angle θ of the sample 5 30 , to achieve the introduction of dispersion difference. In this experiment, the side length of the beam splitter prism 2 is 25.4mm, the refractive index is 1.53626, and the group velocity dispersion coefficient is 50fs 2 / mm, the inclination angle θ of the sample 5 30 The adjustable range is [-5°, 5°], assuming that the incident beam angle θ 10 The reference mirror 4 has an inclination angle of θ 40 The equivalent dispersion introduction effect of the dispersion optimization mechanism was verified under the condition of -5°.

[0072] See Figure 4 . Figure 4 The figure shows the result of the equivalent dispersion introduced by the dispersion-free element. Figure 4 As shown, without the dispersion glass 3, by adjusting the inclination angle θ of the incident light beam 10 , the inclination angle θ of the reference mirror 4 40 , the inclination angle θ of the sample 5 30 The setting can introduce an equivalent dispersion difference between the reference arm and the sample arm. Under the setting conditions of this experiment, the value of the equivalent dispersion difference is equivalent to that of a [-74.2197, 544.8070] ps 2 Therefore, the equivalent dispersion introduction mechanism proposed in this embodiment can be used to achieve dispersion control without adding additional optical components, and has the advantages of simplified structure and flexible adjustment.

[0073] To verify the imaging resolution optimization effect under the intervention of the dispersion optimization mechanism, two experiments were conducted, including: 1. Dispersion-optimized optical computational OCT: the parameters of the dispersion glass 3 were determined based on the dispersion optimization mechanism, thereby achieving system dispersion optimization; 2. Traditional optical computational OCT: the dispersion glass 3 was not used in the optical path. The wavelength range of the light source 1 was 390nm-760nm; the template function of the spatial template 6 was a linear chirp signal cos(ax 2 ), modulation coefficient a=0.3m -2 The dispersion element 7 of the role of the dispersion rate D k =1.8723*10 -8 m; the distance L between the dispersive element 7 and the area array camera 8 is 0.1 m; assuming an optical path difference of 35 μm, the effects of the dispersion optimization mechanism on the system resolution are compared with and without the dispersion optimization mechanism.

[0074] See Figure 5 and Figure 6 . Figure 5 The figure shows the output result of traditional optical computing OCT; Figure 6 The figure shows the OCT output result under dispersion optimization of an embodiment of the present application. Figure 5As shown in the figure, under the dispersion-free optimization, due to the use of fractional-order Fourier transform to approximate the Fourier transform process, the signal intensity of the output A-Scan result is the same as the complex conjugate signal intensity, and the peak intensity is about 70, which shows a significant broadening of the output signal resolution. Figure 6 As shown in the figure, under the dispersion optimization condition, the dispersion optimization offsets the effect of resolution degradation caused by the fractional Fourier transform approximation process and effectively suppresses the complex conjugate component. The peak value of the real signal intensity reaches about 107, which is significantly lower than that of the original signal. Figure 5 The signal resolution is increased by 52%, ensuring that optical computing OCT can achieve high-resolution imaging quality while achieving fast imaging.

[0075] Obviously, the embodiments described above are only some of the embodiments of the present application, rather than all of the embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present application specification and the accompanying drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present application.

Claims

1. A dispersion-optimized parallel optical computing OCT system, characterized by: The system includes a light source, a beam splitter prism, a dispersion glass, a reference mirror, a sample, a two-dimensional space template, a dispersion element, a surface array camera, and an electronic computer; The light source is used to generate parallel broadband light and transmit it to the beam splitter prism; The beam splitter is used to split the incident parallel broadband light into two beams: reference light A and sample light A. The reference light A is transmitted to the dispersion glass, and the sample light A is transmitted to the sample. The sample backscatters the sample light A to form sample light B, which is transmitted to the beam splitter. The dispersion glass optimizes the dispersion of the received reference light A to form a reference light B, which is transmitted to the reference mirror. The reference mirror then reflects the reference light B to form a reference light C. The reference light C passes through the dispersion glass and is transmitted to the beam splitter prism. The sample light B and the reference light C interfere with each other at the beam splitter prism, forming interference light that is transmitted to the two-dimensional space template; The two-dimensional spatial template modulates the interference light and transmits it to the dispersive element. The dispersive element performs spatial mapping and superposition summation on the modulated interference light and outputs the dispersed light to the area array camera. The area array camera collects the spectral information of the received dispersed light and transmits it to the electronic computer. The electronic computer calculates and outputs the A-Scan, B-Scan and enface images of the sample based on the received spectral information.

2. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The total dispersion ΔD of the dispersion glass for the received reference light A is: ΔD=2D glass d Among them, D glass is the unit dispersion of the dispersion glass, and d is the thickness of the dispersion glass.

3. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The total dispersion ΔD of the dispersion glass for the received reference light A is: Among them, a is the modulation coefficient of the two-dimensional space template, D k is the angular dispersion of the dispersion prism, L is the distance between the dispersion prism and the area array camera, and c is the speed of light.

4. A dispersion-optimized parallel optical computing OCT system, characterized by: The system includes a light source, a beam splitter prism, a reference mirror, a sample, a two-dimensional space template, a dispersion element, an area array camera, and an electronic computer; The light source is used to generate parallel broadband light and transmit it to the beam splitter prism; The beam splitter is used to split the incident parallel broadband light into two beams, a reference light A and a sample light A. The reference light A is transmitted to the reference mirror, and the sample light A is transmitted to the sample. The sample backscatters the sample light A to form a sample light B which is transmitted to the beam splitter. The reference mirror reflects the received reference light A to form a reference light C which is transmitted to the beam splitter prism; The sample light B and the reference light C interfere with each other at the beam splitter prism, forming interference light that is transmitted to the two-dimensional space template; The two-dimensional spatial template modulates the interference light and transmits it to the dispersive element. The dispersive element disperses the modulated interference light and outputs the dispersed light to the area array camera. The area array camera collects the spectral information of the received dispersed light and transmits it to the electronic computer. The electronic computer calculates and outputs the A-Scan, B-Scan and enface images of the sample based on the received spectral information.

5. The dispersion-optimized parallel optical computing OCT system according to claim 4, characterized in that: The total dispersion ΔD of the reference light C formed after the reference mirror reflects the received reference light A is: Where n is the refractive index of the beam splitter, H glass is the unit dispersion of the dichroic prism, h is the thickness of the dichroic prism, θ 30 is the angle between the sample and the vertical plane, θ 40 is the angle between the reference mirror and the horizontal plane, θ 10 is the angle between the parallel broadband light and the horizontal plane.

6. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The spatial transmittance of the two-dimensional space template is a linear frequency modulation signal cos(ax 2 ), where a is a constant and x is a spatial coordinate.

7. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The dispersion element is an equilateral dispersion prism, a reflective grating or a transmissive grating.

8. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The two-dimensional spatial template and the dispersive element are used to spatially modulate the interference light and provide dispersion. Mathematically, this is regarded as constructing a mapping relationship from the wavenumber domain to the spatial domain for the interference light signal, and performing an all-optical convolution operation, that is, the convolution between the interference spectrum signal and the two-dimensional spatial template modulation function. When the dispersive element is an equilateral dispersion prism, the incident light path can meet the minimum deflection angle condition.

9. The dispersion-optimized parallel optical computing OCT system according to claim 1, characterized in that: The splitting ratio of the beam splitter prism is set to 5:5, 4:6, 3:7, 2:8, or 1:9 as needed.

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