Surface detection system and method based on polarization imaging

Abstract

The invention relates to the technical field of imaging detection, and particularly provides a surface detection system and method based on polarization imaging. The system comprises a light source, a beam splitter, a reflecting device, a beam combiner, an analyzer and an imaging device, a light source beam along a first light path can be generated based on the light source; the light source light beam can be divided into second signal light and first signal light based on a beam splitter; performing reflection reversing on the second signal light based on a reflection device to obtain second reflection signal light; combining the detection signal light and the first signal light / the second reflection signal light based on a beam combiner to obtain interference signal light; filtering non-depolarized signal light in the interference signal light based on a polarization analyzer; and acquiring a detection image of the to-be-detected surface based on the imaging device. According to the surface detection system based on polarization imaging provided by the invention, the resolution of the detection image of the surface to be detected can be improved, and the surface detection precision under relatively low photon flux is further improved.

Description

Technical Field

[0001] The present application relates to the field of imaging detection technology, and in particular to a surface detection system and method based on polarization imaging. Background Art

[0002] Polarization imaging detection is an important means of detecting surface cleanliness and defects. The target reflects, scatters, refracts and transmits the incident light. The reflected and refracted light contains the polarization characteristics of the target surface, and this characteristic changes with the change of polarization degree, incident angle, target surface material, etc. Therefore, polarization imaging contains rich target surface information. Compared with traditional imaging technology, polarization imaging technology expands the information dimension from light intensity, spectrum, and spatial position to multiple directions such as polarization degree, polarization angle, and ellipticity. In addition, by changing the vibration direction between the two polarized lights, polarization light detection can reduce the intensity of reflected light, enhance the characteristics, and more clearly show the surface characteristics of the target, effectively identifying objects of different materials and different surface states. Therefore, polarization imaging technology has unparalleled advantages over other imaging technologies in the identification and detection of materials, and has a wide range of uses in various fields.

[0003] However, as illumination levels decrease, detector dark noise and electronic readout noise become a significant consideration, degrading the quality of the resulting image. As a result, existing polarization imaging assays have lower accuracy at lower photon fluxes. Summary of the invention

[0004] In view of this, an object of the embodiments of the present application is to provide a surface detection system and method based on polarization imaging, so as to solve the technical problem of low accuracy detection of existing polarization imaging detection under lower photon flux.

[0005] In a first aspect, an embodiment of the present application provides a surface detection system based on polarization imaging, the system comprising: a light source, a beam splitter, a reflective device, a beam combiner, an analyzer, and an imaging device;

[0006] The light source is configured as a light source beam along a first light path;

[0007] The beam splitter is configured to split the light source beam into a second signal light and a first signal light along the first light path;

[0008] The reflective device is disposed in the optical path of the second signal light and is configured to reflect and reverse the second signal light to obtain a second reflected signal light;

[0009] The beam combiner is disposed in the first optical path and is configured to combine the detection signal light and the first signal light / the second reflected signal light to obtain a combined interference signal light, wherein the detection signal light is configured to be obtained after the second reflected signal light / the first signal light is irradiated on the surface to be detected and then returns;

[0010] The polarizer is configured to filter the non-depolarized signal light in the interference signal light;

[0011] The imaging device is configured to receive the filtered interference signal light and obtain a detection image of the surface to be detected.

[0012] In the above implementation process, the surface detection system based on polarization imaging includes: a light source, a beam splitter, a reflector, a beam combiner, an analyzer and an imaging device. Based on the light source, a light source beam can be generated along the first optical path; based on the beam splitter, the light source beam can be divided into a second signal light and a first signal light; based on the reflector, the second signal light is reflected and reversed to obtain a second reflected signal light; based on the beam combiner, the detection signal light and the first signal light / the second reflected signal light are combined to obtain the combined interference signal light; based on the analyzer, the non-depolarized signal light in the interference signal light is filtered; and then based on the imaging device, the detection image of the surface to be detected is obtained. Specifically, based on the surface detection system provided by the present application, the original coherent image of the surface to be detected corresponding to the interference signal light can be obtained, and then the reference signal intensity image of the surface to be detected can be obtained by blocking the second signal light / the first signal light; and the homodyne detection image of the surface to be detected can be obtained based on the original coherent image and the reference signal intensity image. The non-depolarized signal light in the interference signal light is also filtered by the analyzer to eliminate the interference of background light, thereby realizing the homodyne polarization imaging detection of the surface to be detected. The signal light can be enhanced by homodyne detection; combined with polarization imaging, the interference of background light can be eliminated to more accurately determine the particles or defects on the surface to be detected. Therefore, the surface detection system based on polarization imaging provided by the present application can improve the resolution of the detection image of the surface to be detected by homodyne polarization imaging, thereby improving the surface detection accuracy under lower photon flux. The technical problem of low detection accuracy of existing polarization imaging detection under lower photon flux is solved.

[0013] Optionally, in an embodiment of the present application, the optical path of the second signal light and the first optical path of the first signal light are perpendicular to each other; the reflecting device includes a first reflector and a second reflector; the first reflector is configured to reflect the second signal light to obtain signal reflected light; and the second reflector is configured to reflect the signal reflected light to obtain the second reflected signal light.

[0014] In the above implementation process, by setting the first reflector and the second reflector, the difficulty of setting the beam combiner can be reduced, a better beam combining effect can be obtained, and the surface detection accuracy of the polarization imaging-based surface detection system at a lower photon flux can be further improved.

[0015] Optionally, in the embodiment of the present application, the reflective device further includes: a filter; the filter is arranged between the first reflector and the second reflector.

[0016] In the above implementation process, the intensity of the second reflected signal light can be controlled by the filter, thereby reducing the overexposure probability of the imaging device.

[0017] Optionally, in an embodiment of the present application, when the surface to be detected is arranged in the first optical path, the detection signal light is obtained after the first signal light is irradiated on the surface to be detected and returned; the beam combiner is specifically configured to combine the detection signal light and the second reflected signal light to obtain the combined interference signal light.

[0018] Optionally, in an embodiment of the present application, when the surface to be detected is arranged in the optical path of the second reflected signal light, the second reflected signal light is irradiated on the surface to be detected and then returned to obtain the detection signal light; the beam combiner is specifically configured to combine the detection signal light and the first signal light to obtain the combined interference signal light.

[0019] Optionally, in an embodiment of the present application, the system further includes: an imaging lens; the imaging lens is arranged between the beam combiner and the imaging device, or between the beam combiner and the surface to be detected.

[0020] In the above implementation process, the specific position of the imaging lens can be adjusted to avoid irrelevant objects such as the beam combiner from appearing in the detection image, thereby further improving the surface detection accuracy of the system at lower photon flux.

[0021] Optionally, in an embodiment of the present application, the system further includes: a first aperture and a second aperture; the first aperture and the second aperture are arranged along the first optical path, the first aperture is specifically arranged between the light source and the beam splitter, and the second aperture is specifically arranged between the beam splitter and the beam combiner.

[0022] In the above implementation process, the intensity of the light source light beam received by the beam splitter can be controlled by the first aperture, and the intensity of the first signal light received by the beam combiner can be controlled by the second aperture; thereby reducing the overexposure probability of the imaging device.

[0023] In a second aspect, an embodiment of the present application provides a surface detection method based on polarization imaging, which is applied to a surface detection system based on polarization imaging as described in any one of the first aspects above; the surface to be detected is arranged in the first optical path / the optical path of the second reflected signal light;

[0024] The method comprises:

[0025] Based on the imaging device in the surface detection system, an original coherent image of the surface to be detected is obtained by using interference signal light;

[0026] shielding the first signal light / the second signal light, and obtaining a reference signal intensity image based on the imaging device;

[0027] A surface detection result of the surface to be detected is determined based on the original coherence image and the reference signal intensity image.

[0028] In the above implementation process, the surface detection method based on polarization imaging can obtain the original coherent image of the surface to be detected by using interference signal light based on the imaging device in the surface detection system; obtain the reference signal intensity image based on the imaging device by blocking the first signal light / second signal light; and determine the surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image. The surface detection method based on polarization imaging can realize homodyne polarization imaging detection of the surface to be detected based on the original coherent image and the reference signal intensity image; and improve the resolution of the detection image of the surface to be detected by homodyne polarization imaging, thereby improving the surface detection accuracy at lower photon flux. The technical problem of low accuracy detection of existing polarization imaging detection at lower photon flux is solved.

[0029] Optionally, in an embodiment of the present application, determining the surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image includes: obtaining a homodyne polarization detection image of the surface to be detected based on the original coherent image minus the reference signal intensity image; and determining the surface detection result of the surface to be detected based on the homodyne polarization detection image.

[0030] Optionally, in an embodiment of the present application, determining the surface detection result of the surface to be detected based on the homodyne polarization detection image includes: performing Fourier transform on the homodyne polarization detection image to obtain a spectrum detection image; filtering the spectrum detection image to obtain a filtered detection image; performing inverse Fourier transform on the filtered detection image to obtain a surface detection image of the surface to be detected; wherein the surface detection image includes the surface detection result of the surface to be detected.

[0031] The beneficial effects of this application include at least:

[0032] The surface detection system based on polarization imaging includes: a light source, a beam splitter, a reflector, a beam combiner, an analyzer and an imaging device. Based on the light source, a light source beam can be generated along the first optical path; based on the beam splitter, the light source beam can be divided into a second signal light and a first signal light; based on the reflector, the second signal light is reflected and reversed to obtain a second reflected signal light; based on the beam combiner, the detection signal light and the first signal light / the second reflected signal light are combined to obtain the combined interference signal light; based on the analyzer, the non-depolarized signal light in the interference signal light is filtered; and based on the imaging device, the detection image of the surface to be detected is obtained. Specifically, based on the surface detection system provided by the present application, the original coherent image of the surface to be detected corresponding to the interference signal light can be obtained, and then the reference signal intensity image of the surface to be detected can be obtained by blocking the second signal light / the first signal light; and the homodyne detection image of the surface to be detected can be obtained based on the original coherent image and the reference signal intensity image. The non-depolarized signal light in the interference signal light is also filtered by the analyzer to eliminate the interference of background light, thereby realizing the homodyne polarization imaging detection of the surface to be detected. The signal light can be enhanced by homodyne detection; combined with polarization imaging, the interference of background light can be eliminated to more accurately determine the particles or defects on the surface to be detected. Therefore, the surface detection system based on polarization imaging provided by the present application can improve the resolution of the detection image of the surface to be detected by homodyne polarization imaging, thereby improving the surface detection accuracy at a lower photon flux, and solving the technical problem of low detection accuracy of existing polarization imaging detection at a lower photon flux. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic structural diagram of a first surface detection system based on polarization imaging provided in an embodiment of the present application;

[0035] Figure 2 A schematic structural diagram of a second surface detection system based on polarization imaging provided in an embodiment of the present application;

[0036] Figure 3 A schematic structural diagram of a third surface detection system based on polarization imaging provided in an embodiment of the present application;

[0037] Figure 4A schematic diagram of a process flow of a surface detection method based on polarization imaging provided in an embodiment of the present application;

[0038] Figure 5 A schematic flow chart of another surface detection method based on polarization imaging provided in an embodiment of the present application;

[0039] Figure 6 A schematic diagram of a surface detection image provided in an embodiment of the present application;

[0040] Figure 7 A schematic diagram of another surface detection image provided in an embodiment of the present application.

[0041] Figure numerals: 01 - light source; 02 - beam splitter; 03 - reflecting device; 031 - first reflecting mirror; 032 - second reflecting mirror; 033 - filter; 04 - beam combiner; 05 - polarizer; 06 - imaging device; 07 - imaging lens. DETAILED DESCRIPTION

[0042] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0044] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] See also Figure 1 The schematic diagram of the structure of a surface detection system based on polarization imaging provided by an embodiment of the present application is shown. The surface detection system based on polarization imaging includes: a light source 01, a beam splitter 02, a reflector 03, a beam combiner 04, an analyzer 05 and an imaging device 06;

[0046] The light source 01 is configured to generate a light source light beam along a first light path;

[0047] The beam splitter 02 is configured to split the light source light beam into a second signal light and a first signal light along the first light path;

[0048] The reflective device 03 is disposed in the optical path of the second signal light, and the reflective device 03 is configured to reflect and reverse the second signal light to obtain a second reflected signal light;

[0049] The beam combiner 04 is disposed in the first optical path, and is configured to combine the detection signal light and the first signal light / the second reflected signal light to obtain a combined interference signal light, wherein the detection signal light is configured to be obtained after the second reflected signal light / the first signal light is irradiated on the surface to be detected and then returns;

[0050] The polarizer 05 is configured to filter the non-depolarized signal light in the interference signal light;

[0051] The imaging device 06 is configured to receive the filtered interference signal light and obtain a detection image of the surface to be detected.

[0052] The light source 01 may be implemented by a laser source, such as a gas laser source, a semiconductor laser source, or a fiber laser source. The beam splitter 02 may be implemented by a dielectric film reflector or a cubic beam splitter. The optical path of the second signal light may be adjusted according to the actual application. Figure 1 The example only shows the case where the optical path of the second signal light is perpendicular to the first optical path. The reflective device 03 can be implemented by one or more reflectors. Figure 1 The embodiment merely shows that the reflective device 03 is implemented by a reflector. The beam combiner 04 can be implemented by a dielectric film reflector or a cubic beam splitter, etc. The implementation method of the beam combiner 04 can be the same as or different from that of the beam splitter 02. Figure 1 The diagram shows a situation where the analyzer 05 is arranged in the optical path of the interference signal light. The analyzer 05 can be rotated to filter the non-depolarized signal light in the interference signal light, so as to cooperate with the imaging device 06 to realize polarization imaging of the surface to be detected.

[0053] Among them, Figure 1 As shown, the surface to be detected can be set in the first optical path (specifically set on the side of the beam combiner 04 away from the light source 01, and correspondingly, the imaging device 06 can be set in the optical path of the second reflected signal light). In this case, the light reflected by the first signal light from the surface to be detected can be used as the detection signal light; at this time, the beam combiner 04 is specifically configured to combine the detection signal light and the second reflected signal light to obtain the interference signal light. The surface to be detected can also be set in the optical path of the second reflected signal light (specifically set on the side of the beam combiner 04 away from the reflector 03, and correspondingly, the imaging device 06 can be set in the first optical path). In this case, the light reflected by the second reflected signal light from the surface to be detected can be used as the detection signal light; at this time, the beam combiner 04 is specifically configured to combine the detection signal light and the first signal light to obtain the interference signal light.

[0054] Among them, after the light source 01 emits a light beam, it will pass through the beam splitter 02 and be divided into two polarized lights, the first signal light and the second signal light. For example, when the surface to be detected is set in the first optical path, the first signal light is irradiated on the surface to be detected, and the dust / particles / defects on the surface to be detected will produce depolarization, absorption, scattering and other effects on the polarized light (first signal light), so that the polarization state of this part of the light is different from the light reflected from other parts of the surface to be detected. In this case, the second signal light is used as a reference light, and the optical path difference is adjusted by the reflector 03. The beam combiner 04 combines the "first signal light returned from the surface to be detected" and the second reflected signal light. The "first signal light returned from the surface to be detected" includes: the reflected light (non-depolarized signal light) of the surface to be detected and the depolarized light scattered by dust / particles / defects (including part of the non-depolarized signal light). By rotating the polarizer 05, the non-depolarized signal light in the "reflected light of the surface to be detected" and the "depolarized light scattered by dust / particles / defects" can be filtered; and then the polarization imaging of the surface to be detected is realized based on the imaging device 06.

[0055] It can be seen that the surface detection system based on polarization imaging provided by the embodiment of the present application includes: a light source 01, a beam splitter 02, a reflector 03, a beam combiner 04, an analyzer 05 and an imaging device 06; and a high-precision detection image of the surface to be detected can be obtained based on the imaging device 06. Specifically, based on the surface detection system provided by the present application, the original coherent image of the surface to be detected corresponding to the interference signal light can be obtained, and then the reference signal intensity image of the surface to be detected can be obtained by blocking the second signal light / the first signal light; and the homodyne detection image of the surface to be detected can be obtained based on the original coherent image and the reference signal intensity image. The non-depolarized signal light in the interference signal light is also filtered by the analyzer 05 to eliminate the interference of the background light, thereby realizing the homodyne polarization imaging detection of the surface to be detected. The signal light can be enhanced by homodyne detection; combined with polarization imaging, the interference of the background light can be eliminated to more accurately determine the particles or defects on the surface to be detected. Therefore, the surface detection system based on polarization imaging provided by the present application can improve the resolution of the detection image of the surface to be detected through homodyne polarization imaging, thereby improving the surface detection accuracy under low photon flux. The technical problem of low detection accuracy of existing polarization imaging detection under low photon flux is solved.

[0056] Please refer to Figure 2 , Figure 2 A schematic structural diagram of a second surface detection system based on polarization imaging provided in an embodiment of the present application. Figure 2 Specifically shown is a case where the reflective device 03 is implemented by two reflective mirrors (a first reflective mirror 031 and a second reflective mirror 032 ).

[0057] In some optional embodiments, the optical path of the second signal light and the first optical path of the first signal light are perpendicular to each other; the reflective device 03 includes a first reflector 031 and a second reflector 032; the first reflector 031 is configured to reflect the second signal light to obtain signal reflected light; the second reflector 032 is configured to reflect the signal reflected light to obtain the second reflected signal light.

[0058] Among them, by setting the first reflector 031 and the second reflector 032, the difficulty of setting the beam combiner 04 can be reduced, a better beam combining effect can be obtained, and the surface detection accuracy of the polarization imaging-based surface detection system at a lower photon flux can be further improved.

[0059] In some optional embodiments, the reflective device 03 further includes: a filter 033 ; the filter 033 is disposed between the first reflector 031 and the second reflector 032 .

[0060] The filter 033 may be implemented by an absorption filter or an interference filter, etc., which is not specifically limited in the present application. The intensity of the second reflected signal light may be controlled by the filter 033 to reduce the overexposure probability of the imaging device 06 .

[0061] In some optional embodiments, when the surface to be detected is arranged in the first optical path, the first signal light is irradiated on the surface to be detected and then returned to obtain the detection signal light; the combiner 04 is specifically configured to combine the detection signal light and the second reflected signal light to obtain the combined interference signal light.

[0062] in, Figure 2 The case where the surface to be detected is set in the first optical path is exemplarily shown. In the case where the surface to be detected is set in the first optical path, the imaging device 06 can be set in the optical path of the second reflected signal light. At this time, the reference signal intensity image of the surface to be detected can be obtained based on the imaging device 06 by shielding the first signal light.

[0063] Please refer to Figure 3 , Figure 3 A schematic structural diagram of a third surface detection system based on polarization imaging provided in an embodiment of the present application. Figure 3 Specifically, the case where the analyzer 05 is arranged in the optical path of the interference signal light is shown.

[0064] In some optional embodiments, when the surface to be detected is arranged in the optical path of the second reflected signal light, the second reflected signal light is irradiated on the surface to be detected and then returned to obtain the detection signal light; the combiner 04 is specifically configured to combine the detection signal light and the first signal light to obtain the combined interference signal light.

[0065] in, Figure 3 The case where the surface to be detected is arranged in the optical path of the second reflected signal light is exemplarily shown. In the case where the surface to be detected is arranged in the optical path of the second reflected signal light, the imaging device 06 can be arranged in the first optical path. In this case, the reference signal intensity image of the surface to be detected can be obtained based on the imaging device 06 by shielding the second signal light.

[0066] In some optional embodiments, the system further includes: an imaging lens 07; the imaging lens 07 is disposed between the beam combiner 04 and the imaging device 06, or between the beam combiner 04 and the surface to be detected.

[0067] The imaging device 06 may not include an imaging lens, and cooperate with the imaging lens 07 to realize polarization imaging of the surface to be detected. In this case, the specific position of the imaging lens 07 can be adjusted to avoid irrelevant objects such as the beam combiner 04 appearing in the detection image, thereby further improving the surface detection accuracy of the system at a lower photon flux. Figure 2 The imaging lens 07, the beam combiner 04 and the imaging device 06 are exemplarily shown, and the imaging lens 07 is specifically arranged between the beam combiner 04 and the analyzer 05. It should be noted that the imaging lens 07 can also be arranged between the analyzer 05 and the imaging device 06. Figure 3 The example shows that the imaging lens 07 is disposed between the surface to be detected and the beam combiner 04. The specific arrangement position of the imaging lens 07 can be adjusted according to the actual focal length of the imaging lens 07.

[0068] In some optional embodiments, the system also includes: a first aperture and a second aperture; the first aperture and the second aperture are arranged along the first optical path, the first aperture is specifically arranged between the light source 01 and the beam splitter 02, and the second aperture is specifically arranged between the beam splitter 02 and the beam combiner 04.

[0069] The intensity of the light beam from the light source received by the beam splitter 02 can be controlled by the first aperture, and the intensity of the first signal light received by the beam combiner 04 can be controlled by the second aperture, so as to reduce the overexposure probability of the imaging device.

[0070] Please refer to Figure 4 , Figure 4 A schematic flow chart of a surface detection method based on polarization imaging provided in an embodiment of the present application. The surface detection method based on polarization imaging is applied to a surface detection system based on polarization imaging as described in any one of the first aspects above; the surface to be detected is set in the first optical path / second optical path of the reflected signal light.

[0071] The surface detection method based on polarization imaging may include the following steps:

[0072] S101, based on the imaging device in the surface detection system, using interference signal light to obtain an original coherent image of the surface to be detected;

[0073] S102, shielding the first signal light / the second signal light, and obtaining a reference signal intensity image based on the imaging device;

[0074] S103: Determine a surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image.

[0075] Among them, in steps S101-S103, the original coherent image is the polarization imaging of the surface to be detected obtained when no occlusion occurs. The reference signal intensity image is the image obtained when the first signal light / second signal light is blocked. Specifically, when the surface to be detected is set in the first optical path, the reference signal intensity image can be obtained by blocking the first signal light and based on the imaging device. When the surface to be detected is set in the optical path of the second reflected signal light, the reference signal intensity image can be obtained by blocking the second signal light and based on the imaging device. The surface detection result of the surface to be detected can be determined based on the original coherent image, the reference signal intensity image and the homodyne interferometry principle. The surface detection method based on polarization imaging provided in the present application is combined with the homodyne interferometry method on the basis of polarization imaging, which can solve the problem of extremely weak light information detection such as particle size (accuracy of 1μm and below) and lens surface defects (can reach first-level smoothness).

[0076] It should be understood that the surface detection method based on polarization imaging corresponds to the above-mentioned surface detection system embodiment based on polarization imaging. The specific implementation method of the above steps in the surface detection method based on polarization imaging can refer to the relevant description above. In order to avoid repetition, the detailed description is appropriately omitted here.

[0077] Please refer to Figure 5 , Figure 5 A schematic flow chart of another surface detection method based on polarization imaging provided in an embodiment of the present application.

[0078] In some optional embodiments, S103, determining the surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image, includes: S1031, obtaining a homodyne polarization detection image of the surface to be detected based on the original coherent image minus the reference signal intensity image; S1032, determining the surface detection result of the surface to be detected based on the homodyne polarization detection image.

[0079] Among them, the first signal light / the second signal light can be shielded, and multiple reference images can be continuously collected based on the imaging device; and the multiple reference images can be averaged to obtain the above-mentioned reference signal intensity image. Then, the homodyne polarization detection image of the surface to be detected is obtained based on the original coherent image minus the reference signal intensity image. The number of reference images collected can be 5, 10 or other reasonable values.

[0080] In some optional embodiments, S1032, based on the homodyne polarization detection image, determining the surface detection result of the surface to be detected, including: performing Fourier transform on the homodyne polarization detection image to obtain a spectrum detection image; filtering the spectrum detection image to obtain a filtered detection image; performing inverse Fourier transform on the filtered detection image to obtain a surface detection image of the surface to be detected; wherein the surface detection image includes the surface detection result of the surface to be detected.

[0081] Please refer to Figure 6 , Figure 6 A schematic diagram of a surface detection image provided in an embodiment of the present application. Figure 6 Specifically shown is a schematic diagram of a detection image obtained by contaminating a lens by preparing a diluted solution of 200 nm monodisperse polystyrene microspheres, and detecting the contaminated lens surface using the surface detection system based on polarization imaging provided by the present application. Figure 6 The original coherence image, the reference signal intensity image, the zero-difference polarization detection image obtained by subtracting the reference signal intensity image from the original coherence image, the filtered detection image obtained by filtering the spectrum detection image, the spectrum detection image, the filtered detection image obtained by filtering the spectrum detection image, and the surface detection image obtained by inverse Fourier transforming the filtered detection image are shown respectively.

[0082] Please refer to Figure 7 , Figure 7 A schematic diagram of another surface detection image provided in an embodiment of the present application. Figure 7 Specifically shown is a surface detection image obtained by detecting the contaminated lens surface based on the existing polarization imaging detection method.

[0083] from Figure 6 , Figure 7 It can be seen that the surface detection system and method based on polarization imaging provided in the present application can improve the resolution of the detection image of the surface to be detected, thereby improving the surface detection accuracy under lower photon flux, and solving the technical problem of low accuracy of existing polarization imaging detection under lower photon flux.

[0084] In several embodiments provided by the embodiments of the present application, it should be understood that the disclosed device / system and method can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to the multiple embodiments of the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a part of the module, program segment or code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0085] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part.

[0086] The above description is only an optional implementation manner of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiments of the present application, which should be covered within the protection scope of the embodiments of the present application.

Claims

1. A surface detection system based on polarization imaging, characterized in that: The system comprises: a light source, a beam splitter, a reflector, a beam combiner, an analyzer and an imaging device; The light source is configured to generate a light source beam along a first light path; The beam splitter is configured to split the light source beam into a second signal light and a first signal light along the first light path; The reflective device is disposed in the optical path of the second signal light and is configured to reflect and reverse the second signal light to obtain a second reflected signal light; The beam combiner is disposed in the first optical path and is configured to combine the detection signal light and the first signal light / the second reflected signal light to obtain a combined interference signal light, wherein the detection signal light is configured to be obtained after the second reflected signal light / the first signal light is irradiated on the surface to be detected and then returns; The polarizer is configured to filter the non-depolarized signal light in the interference signal light; The imaging device is configured to receive the filtered interference signal light and obtain a detection image of the surface to be detected.

2. The system according to claim 1, characterized in that in, The optical path of the second signal light and the first optical path of the first signal light are perpendicular to each other; the reflecting device includes a first reflecting mirror and a second reflecting mirror; The first reflector is configured to reflect the second signal light to obtain signal reflected light; The second reflector is configured to reflect the signal reflected light to obtain the second reflected signal light.

3. The system according to claim 2, characterized in that in, The reflective device further comprises: a filter; The filter is arranged between the first reflector and the second reflector.

4. The system according to claim 1, characterized in that in, In the case where the surface to be detected is arranged on the first optical path, the detection signal light is obtained after the first signal light is irradiated on the surface to be detected and returned; The beam combiner is specifically configured to combine the detection signal light and the second reflected signal light to obtain combined interference signal light.

5. The system according to claim 1, characterized in that in, In the case where the surface to be detected is arranged in the optical path of the second reflected signal light, the second reflected signal light is irradiated on the surface to be detected and then returns to obtain the detection signal light; The beam combiner is specifically configured to combine the detection signal light and the first signal light to obtain combined interference signal light.

6. The system according to any one of claims 1 to 5, characterized in that: The system further comprises: an imaging lens; The imaging lens is arranged between the beam combiner and the analyzer, or between the beam combiner and the surface to be detected.

7. The system according to claim 1, characterized in that The system further comprises: a first aperture and a second aperture; The first aperture and the second aperture are arranged along the first optical path, the first aperture is specifically arranged between the light source and the beam splitter, and the second aperture is specifically arranged between the beam splitter and the beam combiner.

8. A surface detection method based on polarization imaging, characterized in that: The method is applied to the surface detection system based on polarization imaging as described in any one of claims 1 to 7 above; The surface to be detected is arranged in the optical path of the first optical path / the optical path of the second reflected signal light; The method comprises: Based on the imaging device in the surface detection system, an original coherent image of the surface to be detected is obtained by using interference signal light; shielding the first signal light / the second signal light, and obtaining a reference signal intensity image based on the imaging device; A surface detection result of the surface to be detected is determined based on the original coherence image and the reference signal intensity image.

9. The method according to claim 8, characterized in that The step of determining the surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image includes: Obtaining a homodyne polarization detection image of the surface to be detected based on the original coherence image minus the reference signal intensity image; A surface detection result of the surface to be detected is determined based on the homodyne polarization detection image.

10. The method according to claim 9, characterized in that The step of determining a surface detection result of the surface to be detected based on the homodyne polarization detection image comprises: Performing Fourier transform on the homodyne polarization detection image to obtain a spectrum detection image; Performing filtering on the spectrum detection image to obtain a filtered detection image; Performing an inverse Fourier transform on the filtered detection image to obtain a surface detection image of the surface to be detected; wherein the surface detection image includes a surface detection result of the surface to be detected.

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