Surface profile detection optical system and detection method

Abstract

The present invention belongs to the field of optical detection technology, and relates to a surface profile detection optical system and detection method. The system includes a laser transmitter, a laser beam expansion system, a first 1 / 4 wave plate, a first linear polarizer, a first 1 / 2 wave plate, a linear polarization beam splitter prism, a second 1 / 2 wave plate, a second 1 / 4 wave plate, a galvanometer, a laser convergence system, an off-axis plane reflector, an off-axis parabolic reflector, a pendulum reflector, a measured object surface, a second linear polarizer, an energy beam splitter, a first narrow-band filter, a first CCD detector, a second narrow-band filter, an imaging objective lens, and a second CCD detector. The present application can accurately obtain the surface profile defect information of the measured object surface by analyzing the polarization state of the imaging information of the second CCD detector, thereby realizing the precise detection of high-reflective surface profile defects, and the overall operation is simple and efficient.

Description

Technical Field

[0001] The invention belongs to the technical field of optical detection, and in particular relates to a surface profile detection optical system and a detection method. Background Art

[0002] In the field of optical inspection, the detection of surface defects on highly reflective surfaces is an extremely difficult problem. The existing technology is generally through two-dimensional visual direct imaging. Since highly reflective surfaces are mirror reflections, the projection light path and the test light path obey the law of mirror reflection. When there are defects on the measured surface, the defect position fluctuates, and the defect position does not satisfy the law of mirror reflection. In the actual measurement process, either the test light path just enters the imaging objective lens to reach the detector, or it cannot enter the imaging objective lens at all, which seriously affects the test effect. Summary of the invention

[0003] In view of this, the present invention aims at the deficiencies of the prior art and provides a surface profile detection optical system and detection method, which can well realize the defect detection of highly reflective surfaces in optical detection.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a surface profile detection optical system, the system includes an incident projection optical path, a reflection adjustment optical path and a reflection test optical path:

[0005] The incident projection optical path includes the laser emitter, the laser beam expansion system, the first 1 / 4 wave plate, the first linear polarizer, the first 1 / 2 wave plate, the linear polarization beam splitter prism, the second 1 / 2 wave plate, the second 1 / 4 wave plate, the galvanometer, the laser focusing system, the off-axis parabolic reflection collimation system, the pendulum reflector, and the object surface to be measured, which are arranged in sequence from the laser emitter to the object surface to be measured;

[0006] The reflection adjustment optical path includes the measured object surface, the single pendulum reflector, the off-axis parabolic reflection collimation system, the laser focusing system, the galvanometer, the second 1 / 4 wave plate, the second 1 / 2 wave plate, the linear polarization beam splitter prism, the second linear polarizer, the energy beam splitter, the first narrow-band filter, and the first CCD detector, which are arranged in sequence from the measured object surface to the first CCD detector;

[0007] The reflection test optical path includes the object surface to be measured, the single pendulum reflector, the off-axis parabolic reflection collimation system, the laser focusing system, the galvanometer, the second 1 / 4 wave plate, the second 1 / 2 wave plate, the linear polarization beam splitter prism, the second linear polarizer, the energy beam splitter, the second narrow-band filter, the imaging objective lens, and the second CCD detector, which are arranged in sequence from the object surface to the second CCD detector.

[0008] Optimally, the back focal plane of the laser focusing system coincides with the front focal plane of the off-axis parabolic reflection collimation system.

[0009] Optimally, the off-axis parabolic reflection collimation system comprises an off-axis plane reflector and an off-axis parabolic reflector which are arranged in sequence, the off-axis plane reflector is arranged close to the laser focusing system, and the off-axis parabolic reflector is arranged close to the pendulum reflector.

[0010] Optimally, the polarization splitting plane of the linear polarization splitting prism is set to 45 degrees.

[0011] Optimally, the ratio of the transmitted energy to the reflected energy of the energy splitter is set to 90%:10%.

[0012] Optimally, the wavelength emitted by the laser emitter is in the visible light band or the infrared light band.

[0013] Optimally, the first CCD detector and the second CCD detector are configured as visible light band detectors or infrared light band detectors.

[0014] Optimally, the second 1 / 2 wave plate is rotatable, and the rotation angle range of the second 1 / 2 wave plate is from -90° to +90°.

[0015] A detection method of a surface profile detection optical system comprises the following steps:

[0016] S1. Adjustment of incident projection light path

[0017] The incident projection light path is that the laser transmitter sends out the original laser signal. After the laser beam is expanded by the laser beam expansion system, the light beam is linearly polarized light; then it passes through the first 1 / 4 wave plate, and the linear polarized light becomes elliptically polarized light; then it passes through the first linear polarizer and becomes linearly polarized light; after passing through the first 1 / 2 wave plate, the vibration direction of the light beam is symmetrically deflected along the optical axis of the 1 / 2 wave plate, and the light beam is S light with high polarization degree at this time; the light beam passes through the splitting surface of the linear polarization splitting prism, and the S light is reflected at 90 degrees;

[0018] The second 1 / 2 wave plate is rotatable, and the angle of the second 1 / 2 wave plate is rotated so that the light beam passes through the second 1 / 2 wave plate to obtain linearly polarized light, and the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 45 degrees; then the light beam passes through the second 1 / 4 wave plate, and the light beam becomes left-handed circularly polarized light; the left-handed circularly polarized light enters the laser converging system after being reflected by the galvanometer; after entering the laser converging system, the light beam is reflected by the off-axis parabolic reflection collimation system and becomes a large-aperture left-handed circularly polarized parallel light; the large-aperture left-handed circularly polarized parallel light passes through the single pendulum reflector and is projected onto the measured object surface;

[0019] S2, Reflection adjustment, Light path adjustment

[0020] The reflection adjustment optical path is reflected back from the measured object surface. At this time, the light beam contains the surface shape information of the measured object surface, and the light beam is a large-aperture right-handed circularly polarized light with defects; the large-aperture right-handed circularly polarized light passes through the single pendulum reflector and enters the off-axis parabolic reflection collimation system for convergence. The converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light through the laser convergence system; the small-aperture right-handed circularly polarized parallel light passes through the galvanometer reflection and the second 1 / 4 wave plate in turn to become a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 135 degrees;

[0021] The linearly polarized light passes through the second 1 / 2 wave plate and becomes a P-ray polarized light beam; the P-ray polarized light beam is transmitted through the beam splitting surface of the linear polarization beam splitter prism, and then passes through the second linear polarizer to become a standard P-ray polarized light beam; the light beam is reflected by the energy beam splitter, and part of the energy enters the reflected light path, and is filtered by the first narrow-band filter, and the light beam reaches the first CCD detector;

[0022] According to the real-time feedback of the signal intensity obtained by the first CCD detector, the laser intensity emitted by the laser is adjusted, and the deflection angle of the galvanometer is recorded and adjusted in real time; when the deflection angle of the galvanometer is 0 degrees, the angle of the pendulum reflector is adjusted to make the energy of the first CCD detector the strongest, and the angle of the pendulum reflector 13 is fixedly adjusted;

[0023] S3, reflection test light path

[0024] The reflection test light path is reflected back from the measured object surface. At this time, the light beam contains the surface shape information of the measured object surface, and the light beam is a large-aperture right-handed circularly polarized light with defects; the light beam passes through a single pendulum reflector and enters the off-axis parabolic reflection collimation system for convergence; the converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light by a laser convergence system; the small-aperture right-handed circularly polarized parallel light is reflected by the galvanometer and the second 1 / 4 wave plate in turn, and becomes a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 135 degrees; the linearly polarized light becomes a P-ray polarized light beam after passing through the second 1 / 2 wave plate; the P-ray polarized light beam is transmitted through the splitting surface of the linear polarization beam splitter prism, and then becomes a standard P-ray polarized light after passing through the second linear polarizer; the P-ray polarized light is transmitted through the energy beam splitter, and most of the energy enters the transmission light path, and passes through the second narrow-band filter and the imaging objective lens in turn, and finally forms a clear image on the second CCD detector; the surface shape defect information of the measured object surface can be obtained by analyzing the polarization state of the imaging information of the second CCD detector.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a surface profile detection optical system and detection method, which adopts the settings of incident projection optical path, reflection adjustment optical path and reflection test optical path, and can accurately obtain the surface profile defect information of the measured object surface by analyzing the polarization state of the imaging information of the second CCD detector, so as to realize the precise detection of high-reflective surface profile defects. The overall operation is simple and efficient, and the defect detection of high-reflective surface can be easily realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structural arrangement of the present invention.

[0028] Figure 2 It is a schematic diagram of the incident projection light path of the present invention.

[0029] Figure 3 It is a schematic diagram of the reflection adjustment light path of the present invention.

[0030] Figure 4 It is a schematic diagram of the reflection test light path of the present invention.

[0031] Figure 5 It is a schematic diagram of the full optical path of the projection test of the present invention.

[0032] Figures indicate: 1: laser emitter, 2: laser beam expansion system, 3: first 1 / 4 wave plate, 4: first linear polarizer, 5: first 1 / 2 wave plate, 6: linear polarization beam splitter, 7: second 1 / 2 wave plate, 8: second 1 / 4 wave plate, 9: galvanometer, 10: laser focusing system, 11: off-axis plane mirror, 12: off-axis parabolic mirror, 13: pendulum mirror, 14: measured object plane, 15: second linear polarizer, 16: energy beam splitter, 17: first narrow-band filter, 18: first CCD detector, 19: second narrow-band filter, 20: imaging objective, 21: second CCD detector. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0034] The existing technology is generally a two-dimensional visual direct imaging method. Since the high-reflective surface belongs to mirror reflection, the projection light path and the test light path obey the law of mirror reflection. When there are defects on the measured surface, the defect position will fluctuate. The defective position does not satisfy the law of mirror reflection. In the actual measurement process, either the test light path just enters the imaging objective lens to reach the detector, or it cannot enter the imaging objective lens at all, which seriously affects the test effect. In order to solve this industry pain point, the present invention provides an optical system and detection method for surface defect detection, which can well realize high-reflective surface defect detection.

[0035] Example: Figure 1 and Figure 5 As shown, a surface profile detection optical system includes an incident projection light path, a reflection adjustment light path and a reflection test light path.

[0036] like Figure 2 As shown, the incident projection optical path includes a laser emitter 1, a laser beam expansion system 2, a first 1 / 4 wave plate 3, a first linear polarizer 4, a first 1 / 2 wave plate 5, a linear polarization beam splitter prism 6, a second 1 / 2 wave plate 7, a second 1 / 4 wave plate 8, a galvanometer 9, a laser converging system 10, an off-axis parabolic reflection collimation system, a pendulum reflector 13, and the object surface 14 to be measured, which are arranged in sequence from the laser emitter 1 to the object surface 14 to be measured.

[0037] like Figure 3 As shown, the reflection adjustment optical path includes the measured object surface 14, the single pendulum reflector 13, the off-axis parabolic reflection collimation system, the laser focusing system 10, the galvanometer 9, the second 1 / 4 wave plate 8, the second 1 / 2 wave plate 7, the linear polarization beam splitter prism 6, the second linear polarizer 15, the energy beam splitter 16, the first narrow-band filter 17, and the first CCD detector 18, which are arranged in sequence from the measured object surface 14 to the first CCD detector 18.

[0038] like Figure 4 As shown, the reflection test optical path includes the measured object surface 14, the pendulum reflector 13, the off-axis parabolic reflection collimation system, the laser focusing system 10, the galvanometer 9, the second 1 / 4 wave plate 8, the second 1 / 2 wave plate 7, the linear polarization beam splitter prism 6, the second linear polarizer 15, the energy beam splitter 16, the second narrow-band filter 19, the imaging objective lens 20, and the second CCD detector 21, which are arranged in sequence from the measured object surface 14 to the second CCD detector 21.

[0039] The back focal plane of the laser converging system 10 coincides with the front focal plane of the off-axis parabolic reflection collimation system. The off-axis parabolic reflection collimation system comprises an off-axis plane reflector 11 and an off-axis parabolic reflector 12 which are arranged in sequence, the off-axis plane reflector is arranged close to the laser converging system 10, and the off-axis parabolic reflector 12 is arranged close to the pendulum reflector 13. The apertures of the off-axis plane reflector 11 and the off-axis parabolic reflector 12 can be changed to different apertures according to the size of the object surface 14 to be measured.

[0040] The polarization splitting surface of the linear polarization beam splitter prism 6 is set to 45 degrees, and of course the polarization splitting surface can also be set to other angles. In this embodiment, the linear polarization beam splitter prism 6 uses a 45-degree linear polarization beam splitter prism 6 for illustration. The ratio of the transmitted energy to the reflected energy of the energy splitter 16 is preferably set to 90%:10%, and can also be set to other ratios.

[0041] The wavelength emitted by the laser emitter 1 is in the visible light band or the infrared light band. The first CCD detector 18 and the second CCD detector 21 are the same type of detectors, and can be set as a visible light band detector or an infrared light band detector according to the wavelength selected by the laser generator.

[0042] The second 1 / 2 wave plate 7 is rotatable, and the rotation angle range of the second 1 / 2 wave plate 7 is -90° to +90°. The rotation operation of the second 1 / 2 wave plate 7 can be realized by configuring a precise rotation adjustment structure on the second 1 / 2 wave plate 7, and specifically, a precise electric-controlled rotating stage can be used to control the rotation angle adjustment of the second 1 / 2 wave plate 7.

[0043] A detection method of a surface profile detection optical system comprises the following steps:

[0044] S1. Adjust the incident projection light path.

[0045] The incident projection light path is the original laser signal emitted by the laser transmitter 1, which is expanded to the required size by the laser beam expansion system 2. At this time, the light beam is linearly polarized light. Then, after passing through the first 1 / 4 wave plate 3, the linear polarized light becomes elliptically polarized light. Then, after passing through the first linear polarizer 4, the light beam becomes linearly polarized light. After passing through the first 1 / 2 wave plate 5, the vibration direction of the light beam is symmetrically deflected along the optical axis of the 1 / 2 wave plate. At this time, the light beam is S light with a high degree of polarization. The light beam passes through the splitting surface of the 45-degree linear polarization splitter prism 6, and the S light is reflected at 90 degrees.

[0046] The second 1 / 2 wave plate 7 is rotatable. The angle of the second 1 / 2 wave plate 7 is rotated so that the light beam passes through the second 1 / 2 wave plate 7 to obtain linear polarized light, and the angle between the linear polarized light and the optical axis of the second 1 / 4 wave plate 8 is 45 degrees. Then the light beam passes through the second 1 / 4 wave plate 8 and becomes left-handed circularly polarized light. The left-handed circularly polarized light is reflected by the galvanometer 9, and the galvanometer 9 itself can achieve a certain angle of deflection, and can scan the light beam up and down to achieve measurement of different field of view ranges.

[0047] The off-axis plane reflector 11 and the off-axis parabolic reflector 12 form an off-axis parabolic reflective collimation system, wherein the rear focal plane of the laser converging system 10 coincides with the front focal plane of the off-axis parabolic reflective collimation system, and the light beam enters the laser converging system 10 after being reflected by the galvanometer 9. After entering the laser converging system 10, the light beam is a large-aperture left-handed circularly polarized parallel light after being reflected by the off-axis parabolic reflective collimation system. The pendulum reflector 1313 can be finely adjusted in angle, and the large-aperture left-handed circularly polarized parallel light is projected onto the measured object surface 14 after passing through the pendulum reflector 13.

[0048] S2, reflection adjustment light path adjustment.

[0049] The reflection adjustment optical path is reflected back from the measured object surface 14. At this time, the light beam contains the surface profile information of the measured object surface 14, and the light beam is a large-aperture right-handed circularly polarized light with defects. After passing through the pendulum reflector 13, the large-aperture right-handed circularly polarized light enters the off-axis parabolic reflection collimation system for convergence, and the converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light through the laser convergence system 10. The small-aperture right-handed circularly polarized parallel light is reflected by the galvanometer 9 and the second 1 / 4 wave plate 8 in turn to become a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate 8 is 135 degrees.

[0050] The linearly polarized light becomes a P-ray polarized light beam after passing through the second 1 / 2 wave plate 7. The P-ray polarized light beam is transmitted through the beam splitting surface of the linear polarization beam splitter prism 6, and then becomes a standard P-ray polarized light after passing through the second linear polarizer 15. The light beam is reflected by the energy beam splitter 16, and a small part of the energy enters the reflected light path, and after being filtered by the first narrow-band filter 17, the light beam reaches the first CCD detector 18.

[0051] According to the real-time feedback of the signal intensity obtained by the first CCD detector 18, the laser intensity emitted by the laser is adjusted, and the deflection angle of the galvanometer 9 is recorded and adjusted in real time. When the deflection angle of the galvanometer 9 is 0 degrees, the angle of the pendulum reflector 13 is adjusted to make the energy of the first CCD detector 18 the strongest, and the angle of the pendulum reflector 1313 is fixedly adjusted.

[0052] S3, reflection test light path.

[0053] The reflection test light path is reflected back from the measured object surface 14. At this time, the light beam contains the surface profile information of the measured object surface 14, and the light beam is a large-aperture right-handed circularly polarized light with defects. The light beam passes through the pendulum reflector 13 and enters the off-axis parabolic reflection collimation system for convergence. The converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light by the laser convergence system 10. The small-aperture right-handed circularly polarized parallel light is reflected by the galvanometer 9 and the second 1 / 4 wave plate 8 in turn, and becomes a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate 8 is 135 degrees. The linearly polarized light becomes a P-ray polarized light beam after passing through the second 1 / 2 wave plate 7. The P-ray polarized light beam is transmitted through the splitting surface of the linear polarization beam splitter prism 6, and then becomes a standard P-ray polarized light after passing through the second linear polarizer 15. The P-ray polarized light is transmitted through the energy beam splitter 16, and most of the energy enters the transmission light path, and passes through the second narrow-band filter 19 and the imaging objective lens 20 in turn, and finally is clearly imaged on the second CCD detector 21. By analyzing the polarization state of the imaging information of the second CCD detector 21 , the surface defect information of the measured object surface 14 can be obtained.

[0054] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A surface profile detection optical system, characterized in that: The system includes an incident projection optical path, a reflection adjustment optical path and a reflection test optical path: The incident projection optical path includes the laser emitter, the laser beam expansion system, the first 1 / 4 wave plate, the first linear polarizer, the first 1 / 2 wave plate, the linear polarization beam splitter prism, the second 1 / 2 wave plate, the second 1 / 4 wave plate, the galvanometer, the laser focusing system, the off-axis parabolic reflection collimation system, the pendulum reflector and the object surface to be measured, which are arranged in sequence from the laser emitter to the object surface to be measured; The reflection adjustment optical path includes the measured object surface, the single pendulum reflector, the off-axis parabolic reflection collimation system, the laser focusing system, the galvanometer, the second 1 / 4 wave plate, the second 1 / 2 wave plate, the linear polarization beam splitter prism, the second linear polarizer, the energy beam splitter, the first narrow-band filter and the first CCD detector, which are arranged in sequence from the measured object surface to the first CCD detector; The reflection test optical path includes the measured object surface, the single pendulum reflector, the off-axis parabolic reflection collimation system, the laser focusing system, the galvanometer, the second 1 / 4 wave plate, the second 1 / 2 wave plate, the linear polarization beam splitter prism, the second linear polarizer, the energy beam splitter, the second narrow-band filter, the imaging objective lens and the second CCD detector, which are arranged in sequence from the measured object surface to the second CCD detector; The rear focal plane of the laser converging system coincides with the front focal plane of the off-axis parabolic reflection collimation system; The off-axis parabolic reflection collimation system comprises an off-axis plane reflector and an off-axis parabolic reflector which are arranged in sequence, wherein the off-axis plane reflector is arranged close to the laser focusing system, and the off-axis parabolic reflector is arranged close to the pendulum reflector; The second 1 / 2 wave plate is rotatable, and the rotation angle range of the second 1 / 2 wave plate is from -90° to +90°.

2. A surface profile detection optical system according to claim 1, characterized in that: The polarization splitting plane of the linear polarization splitting prism is set to 45 degrees.

3. A surface profile detection optical system according to claim 1, characterized in that: The ratio of the transmitted energy to the reflected energy of the energy splitter is set to 90%:10%.

4. A surface profile detection optical system according to claim 1, characterized in that: The wavelength emitted by the laser transmitter is in the visible light band or the infrared light band.

5. A surface profile detection optical system according to claim 4, characterized in that: The first CCD detector and the second CCD detector are configured as visible light band detectors or infrared light band detectors.

6. A detection method for a surface profile detection optical system according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, incident projection light path adjustment; The incident projection light path is that the laser transmitter sends out the original laser signal. After the laser beam is expanded by the laser beam expansion system, the light beam is linearly polarized light; then it passes through the first 1 / 4 wave plate, and the linear polarized light becomes elliptically polarized light; then it passes through the first linear polarizer and becomes linearly polarized light; after passing through the first 1 / 2 wave plate, the vibration direction of the light beam is symmetrically deflected along the optical axis of the 1 / 2 wave plate, and the light beam is S light with high polarization degree at this time; the light beam passes through the splitting surface of the linear polarization splitting prism, and the S light is reflected at 90 degrees; The second 1 / 2 wave plate is rotatable, and the angle of the second 1 / 2 wave plate is rotated so that the light beam passes through the second 1 / 2 wave plate to obtain linearly polarized light, and the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 45 degrees; then the light beam passes through the second 1 / 4 wave plate, and the light beam becomes left-handed circularly polarized light; the left-handed circularly polarized light enters the laser converging system after being reflected by the galvanometer; after entering the laser converging system, the light beam is reflected by the off-axis parabolic reflection collimation system and becomes a large-aperture left-handed circularly polarized parallel light; the large-aperture left-handed circularly polarized parallel light passes through the single pendulum reflector and is projected onto the measured object surface; S2, reflection adjustment, light path adjustment; The reflection adjustment optical path is reflected back from the measured object surface. At this time, the light beam contains the surface shape information of the measured object surface, and the light beam is a large-aperture right-handed circularly polarized light with defects; the large-aperture right-handed circularly polarized light passes through the single pendulum reflector and enters the off-axis parabolic reflection collimation system for convergence. The converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light through the laser convergence system; the small-aperture right-handed circularly polarized parallel light passes through the galvanometer reflection and the second 1 / 4 wave plate in turn to become a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 135 degrees; The linearly polarized light passes through the second 1 / 2 wave plate and becomes a P-ray polarized light beam; the P-ray polarized light beam is transmitted through the beam splitting surface of the linear polarization beam splitter prism, and then passes through the second linear polarizer to become a standard P-ray polarized light beam; the light beam is reflected by the energy beam splitter, and part of the energy enters the reflected light path, and is filtered by the first narrow-band filter, and the light beam reaches the first CCD detector; According to the real-time feedback of the signal intensity obtained by the first CCD detector, the laser intensity emitted by the laser is adjusted, and the deflection angle of the galvanometer is recorded and adjusted in real time; when the deflection angle of the galvanometer is 0 degrees, the angle of the pendulum reflector is adjusted to make the energy of the first CCD detector the strongest, and the angle of the pendulum reflector is fixedly adjusted; S3, reflection test light path; The reflection test light path is reflected back from the measured object surface. At this time, the light beam contains the surface shape information of the measured object surface, and the light beam is a large-aperture right-handed circularly polarized light with defects; the light beam passes through a single pendulum reflector and enters the off-axis parabolic reflection collimation system for convergence; the converged light beam is collimated into a small-aperture right-handed circularly polarized parallel light by a laser convergence system; the small-aperture right-handed circularly polarized parallel light is reflected by the galvanometer and the second 1 / 4 wave plate in turn, and becomes a linearly polarized light. At this time, the angle between the linearly polarized light and the optical axis of the second 1 / 4 wave plate is 135 degrees; the linearly polarized light becomes a P-ray polarized light beam after passing through the second 1 / 2 wave plate; the P-ray polarized light beam is transmitted through the splitting surface of the linear polarization beam splitter prism, and then becomes a standard P-ray polarized light after passing through the second linear polarizer; the P-ray polarized light is transmitted through the energy beam splitter, and most of the energy enters the transmission light path, and passes through the second narrow-band filter and the imaging objective lens in turn, and finally forms a clear image on the second CCD detector; the surface shape defect information of the measured object surface can be obtained by analyzing the polarization state of the imaging information of the second CCD detector.

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