CN-119619017-B - Surface detection system and method based on polarization imaging

CN119619017BCN 119619017 BCN119619017 BCN 119619017BCN-119619017-B

Abstract

The application 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, wherein a light source beam along a first light path can be generated based on the light source, the light source beam can be divided into second signal light and first signal light based on the beam splitter, the second signal light is reflected and reversed based on the reflecting device to obtain second reflected signal light, the beam combiner is used for combining the detected signal light and the first signal light/the second reflected signal light to obtain interference signal light, the analyzer is used for filtering undeviated signal light in the interference signal light, and then the imaging device is used for obtaining a detection image of a surface to be detected. The surface detection system based on polarization imaging can improve the resolution of the detection image of the surface to be detected, and further improve the surface detection precision under lower photon flux.

Inventors

LUO XIANGANG
PENG HAO
CHEN LIANWEI
YE WENYI
LI YANG
PU MINGBO
ZENG QINGJI

Assignees

中国科学院光电技术研究所

Dates

Publication Date: 20260512
Application Date: 20241231

Claims (9)

1. A surface detection system based on polarization imaging is characterized by comprising a light source, a beam splitter, a reflecting device, 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 optical path; The reflecting device is arranged in the light path of the second signal light and is configured to reflect and reverse the second signal light so as to obtain second reflected signal light; the beam combiner is arranged in the first light path and is configured to combine detection signal light and the first signal light/the second reflected signal light to obtain interference signal light after beam combination, wherein the detection signal light is configured to be obtained after the second reflected signal light/the first signal light is irradiated on a surface to be detected to return; The analyzer is configured to filter non-depolarized signal light in the interference signal light, wherein the non-depolarized signal light comprises reflected light of the surface to be detected and non-depolarized signal light in depolarized light scattered by dust/particles/defects; The imaging device is configured to receive the filtered interference signal light and obtain an original coherent image of the surface to be detected, and is configured to receive the second reflected signal light/the first signal light and obtain a corresponding reference signal intensity image when the first signal light/the second signal light is blocked, wherein the original coherent image subtracts the reference signal intensity image to obtain a homodyne polarization detection image of the surface to be detected; wherein 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.
2. The system of claim 1, wherein the optical path of the second signal light and the first optical path of the first signal light are perpendicular to each other; the first reflecting mirror is configured to reflect the second signal light to obtain signal reflected light; The second reflecting mirror is configured to reflect the signal reflected light to obtain the second reflected signal light.
3. The system of claim 2, wherein the reflecting device further comprises a filter; The optical filter is arranged between the first reflecting mirror and the second reflecting mirror.
4. The system according to claim 1, wherein the detection signal light is obtained after the first signal light is irradiated to the surface to be detected and returned, with the surface to be detected being disposed in the first optical path; The beam combiner is specifically configured to combine the detection signal light and the second reflected signal light to obtain interference signal light after beam combination.
5. The system according to claim 1, wherein in a case where the surface to be detected is provided in an optical path of the second reflected signal light, the second reflected signal light is irradiated to the surface to be detected to return 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 interference signal light after beam combination.
6. The system of claim 1, further comprising a first aperture and a second aperture; The first aperture and the second aperture are arranged along the first light 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.
7. A surface detection method based on polarization imaging, characterized in that the method is applied to the surface detection system based on polarization imaging according to any one of the claims 1-6, wherein the surface to be detected is arranged in the first optical path/the optical path of the second reflected signal light; the method comprises the following steps: acquiring an original coherent image of the surface to be detected by utilizing interference signal light based on an imaging device in the surface detection system; Shielding the first signal light/the second signal light, and obtaining a reference signal intensity image based on the imaging device; And determining a surface detection result of the surface to be detected based on the original coherent image and the reference signal intensity image.
8. The method of claim 7, wherein the determining the surface detection result of the surface to be detected based on the raw coherent image and the reference signal intensity image comprises: Subtracting the reference signal intensity image from the original coherent image to obtain a homodyne polarization detection image of the surface to be detected; And determining a surface detection result of the surface to be detected based on the homodyne polarization detection image.
9. The method of claim 8, wherein the determining the 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 frequency spectrum detection image; Filtering the spectrum detection image to obtain a filtering detection image; And 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 comprises a surface detection result of the surface to be detected.

Description

Surface detection system and method based on polarization imaging Technical Field The application relates to the technical field of imaging detection, in particular to a surface detection system and method based on polarization imaging. Background Polarization imaging detection is an important means for detecting surface cleanliness and defects. The object reflects, scatters, refracts, and transmits incident light, and in the reflected and refracted light, the polarization characteristics of the object surface are included, and such characteristics vary with changes in the degree of polarization, the angle of incidence, the material of the object surface, and so forth. Thus, polarized imaging contains a rich target surface information. Compared with the traditional imaging technology, the polarization imaging technology expands the information dimension from light intensity, spectrum and space position to multiple directions of polarization degree, polarization angle, ellipsometry and the like. In addition, by changing the vibration direction between the two polarized lights, the polarized light detection can reduce the intensity of reflected light and enhance the characteristics, and can more clearly represent the surface characteristics of the target, thereby effectively identifying objects with different materials and different surface states. Therefore, the polarization imaging technology has incomparable advantages to other imaging technologies in the aspects of substance identification and detection, and has wide application in various fields. However, as the illumination level decreases, dark noise and electronic readout noise of the detector become important considerations, which can reduce the quality of the resulting image. Thus, existing polarized imaging detection has lower accuracy detection at lower photon fluxes. Disclosure of Invention Accordingly, an objective of the embodiments of the present application is to provide a surface detection system and method based on polarization imaging, which are used for solving the technical problem of low precision detection under low photon flux in the existing polarization imaging detection. In a first aspect, embodiments of the present application provide a surface detection system based on polarized imaging, the system comprising a light source, a beam splitter, a reflecting device, a beam combiner, an analyzer, and an imaging device; The light source is configured as 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 optical path; The reflecting device is arranged in the light path of the second signal light and is configured to reflect and reverse the second signal light so as to obtain second reflected signal light; the beam combiner is arranged in the first light path and is configured to combine the detection signal light and the first signal light/the second reflected signal light to obtain interference signal light after beam combination, wherein the detection signal light is configured to be obtained after the second reflected signal light/the first signal light is irradiated on a surface to be detected to return; The analyzer is configured to filter undeviated 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. In the implementation process, the surface detection system based on polarization imaging comprises a light source, a beam splitter, a reflecting device, a beam combiner, an analyzer and an imaging device. The method comprises the steps of generating a light source beam along a first light path based on a light source, dividing the light source beam into a second signal light and a first signal light based on a beam splitter, carrying out reflection reversing on the second signal light based on a reflecting device to obtain a second reflected signal light, combining the detected signal light and the first signal light/the second reflected signal light based on a beam combiner to obtain combined interference signal light, filtering undeviated signal light in the interference signal light based on an analyzer, and obtaining a detection image of a surface to be detected based on an imaging device. Specifically, based on the surface detection system provided by the 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 shielding the second signal light/the first signal light, so that 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 interference of background light is eliminated by filtering undeviated