Multistage light splitting conventional polarizer dynamic interferometer

Abstract

The invention relates to the field of optical system surface type interference measurement, in particular to a multi-stage light splitting conventional polarizer dynamic interferometer which comprises a laser assembly, a light beam shaping and filtering assembly, a light beam collimation assembly, a contrast adjusting assembly, a polarization light splitting assembly, a beam expanding assembly, a multi-stage light splitting assembly, an imaging assembly and the like. Partial polarized light emitted by the laser assembly is shaped and filtered through the beam shaping and filtering assembly to form spherical light waves, then the spherical light waves are collimated through the beam collimation assembly to form collimated partial polarized light, the contrast can be adjusted by rotating the contrast adjusting assembly, and the collimated partial polarized light is divided into P light and S light after passing through the polarization beam splitting assembly. The invention provides a multi-stage light splitting conventional polarizer dynamic interferometer, which realizes that four interference fringe patterns which are separated by a quarter of wavelength are simultaneously generated in four areas of a camera by utilizing multi-stage light splitting and a conventional polarizer, and the surface type of a measured optical system can be solved through calculation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical surface profile interferometry, and in particular to a multi-stage light splitting conventional polarizer dynamic interferometer. BACKGROUND

[0002] Interferometers are used to measure the surface profile of optical systems. There are various classifications of interferometers, and different types of interferometers have different advantages and disadvantages. Single-path interferometers and multi-path interferometers are distinguished by structure. In single-path interferometers, the interfering waves propagate through the same path, such as equal inclination interference and equal thickness interference. The advantages of such interferometers are their high precision and resistance to interference, and they have a wide range of applications in aviation, aerospace, geological surveying, and other fields, and can be used for precise measurement of physical quantities such as length, angle, and strain, and can also be used for the development and manufacture of spectrometers. In multi-path interferometers, the interfering waves do not propagate through the same path. Common examples include Michelson interferometers, which have the advantage of being able to measure length and refractive index, and are widely used in modern physics and modern metrology, such as in the study of the fine structure of spectral lines and the calibration of standard meters using light waves. The disadvantage is that when the optical path of the two beams is long or when large-aperture components are being detected, the two optical paths are often subject to different external disturbances (such as mechanical vibrations and temperature fluctuations), which can cause the interference fringes to be unstable, and even severely affect the measurement.

[0003] Common specific types of interferometers include white light interferometers, which have the advantage of being able to measure three-dimensional surfaces and surface roughness, with a surface height measurement range of 1 nm to 10 mm and a vertical resolution of 0.1 nm. However, they have the disadvantage of requiring a high-precision reference optical flat. Rayleigh interferometers have the advantage of being a typical interferometer that measures the relative refractive index by moving the fringes, but the measurement accuracy is limited by the observation and judgment of the fringe movement. Fizeau interferometers have the advantage of being a common-path interferometer in which the reference light and the sensing light travel along the same optical path, which can better overcome external interference and can be used to measure optical flatness and spherical surface profile error. These types of interferometers typically use a time phase shift method to collect interference patterns with a certain phase difference at different times in a time sequence, and the surface profile is calculated by solving the equations. The time phase shift method is quite sensitive to external interference, so dynamic interferometers that use a spatial phase shift method have been developed.

[0004] Dynamic interferometer is a kind of high-precision measuring instrument, which plays an important role in the field of optical measurement, and has strong anti-interference ability. Dynamic interferometer uses dynamic interference measurement technology, and the collection time is very short, so the instrument is not sensitive to vibration and air turbulence, and can be used in harsh environments such as production workshop, clean room and environmental test room. Different types of dynamic interferometers have different principles. 4D dynamic interferometer uses the principle of polarized light interference, converts the time phase shift method of traditional phase shift interferometer into spatial phase shift method, so that full resolution measurement can be realized within one frame frequency. The laser emitted by the light source is divided into two beams with different polarization states by a polarizing beam splitter prism, and is respectively shot to the measured optical system and the reference mirror. The measurement information is obtained by related processing, and full resolution measurement can be realized within one camera frame frequency.

[0005] Short coherence Fizeau dynamic interferometer uses a spatial synchronous phase shift method based on circularly polarized light interference, analyzes the phase shift principle of two beams of circularly polarized light with opposite rotation and fixed phase difference, and can synchronously collect four interference fringe patterns with phase difference of 90 degrees. Short coherence Fizeau dynamic interferometer has certain advantages in high-precision measurement of optical systems or optical elements under complex environmental conditions. It is equipped with four high-resolution CCD cameras to realize high-resolution dynamic acquisition of images, and the overall structure of the system adopts a common-path Fizeau structure, so it has strong anti-vibration and anti-environmental disturbance ability.

[0006] 4D dynamic interferometer realizes the simultaneous acquisition of four interference patterns with phase difference of 90 degrees by adding a micro-polarizer in front of the camera imaging target surface. Each adjacent four pixels on the camera is a group, and each pixel corresponds to an interference pattern with a phase, so the position matching degree of the micro-polarizer to the camera pixels has high requirements. And only the corresponding type of camera can be matched, most of the general specification cameras cannot be used, which brings limitations. Short coherence Fizeau dynamic interferometer uses four cameras to simultaneously collect interference patterns of interference fringes with phase difference of 90 degrees. Although there is no camera limitation problem of 4D dynamic interferometer, the images of the four cameras cannot be completely synchronized, and there are differences in the response characteristics between different cameras.

[0007] The present application is proposed to overcome the shortcomings of the prior art. SUMMARY

[0008] The purpose of the present application is to overcome the shortcomings of the prior art, and provide a multi-stage light splitting conventional polarizer dynamic interferometer.

[0009] The present application can be realized by the following technical solutions:

[0010] The application discloses a multi-stage light splitting conventional polarizer dynamic interferometer, which comprises a mounting base plate, a laser assembly, a microscope, a light beam shaping filter assembly, a light beam collimation assembly, a contrast focusing assembly, a mirror assembly one, a polarization light splitting assembly, a beam expander front assembly, a mirror assembly two, a beam expander rear assembly, a beam expander, a multi-stage light splitting assembly, an imaging assembly focusing assembly, an imaging assembly receiving assembly, an imaging assembly and a window assembly.

[0011] Preferably, the light beam collimation assembly comprises a compression ring, a collimation lens and a collimation lens fixing support, the collimation lens fixing support is adjusted so that the focal point of the collimation lens coincides with the pinhole of the filter assembly, and the collimated light emitted from the collimation lens is parallel to the surface of the mounting base plate.

[0012] Preferably, the contrast adjusting assembly comprises a compression ring, a circular linear polarizer and a circular linear polarizer fixing support, the contrast of P light and S light split from the polarization light splitting assembly can be adjusted by rotating the circular linear polarizer.

[0013] Preferably, the polarization light splitting assembly comprises a polarization light splitting prism, a polarization light splitting fixing support, a reference light path quarter-wave plate, a reference mirror, an imaging light path quarter-wave plate and a compression ring.

[0014] Preferably, the polarization light splitting prism is installed in a square cavity of the polarization light splitting fixing support, the reference light path quarter-wave plate, the reference mirror and the imaging light path quarter-wave plate are installed in mounting holes of the polarization light splitting fixing support. The reference light path quarter-wave plate is used for conversion between P light and S light, and the imaging light path quarter-wave plate is used for converting linearly polarized light into elliptically polarized light (including circularly polarized light). The mixed elliptically polarized light output from the polarization light splitting assembly 8 is a mixture of light beams returned along the reference light path and the measurement light path.

[0015] Preferably, the beam expander front assembly comprises a measurement light path quarter-wave plate, a focusing lens and a focusing lens fixing support 9, the measurement light path quarter-wave plate is used for converting S light returned along the original path of the measured optical system into P light, and the focusing lens is matched with the beam expander rear assembly to increase the measurement aperture.

[0016] Preferably, the multi-stage light splitting assembly includes a multi-stage light splitting front group and a multi-stage light splitting rear group, a multi-stage light splitting front group half-transmission half-reflection mirror and a multi-stage light splitting front group mirror are fixed on the multi-stage light splitting front group support, and the half-transmission half-reflection mirror and the mirror are both installed at 45° to the optical axis of the light beam, two multi-stage light splitting rear group half-transmission half-reflection mirrors and two multi-stage light splitting rear group mirrors are fixed on the multi-stage light splitting rear group support, and the half-transmission half-reflection mirrors and the mirrors are both installed at 45° to the optical axis of the light beam, and four mixed elliptical polarized light (including circular polarized light) are output from the multi-stage light splitting assembly.

[0017] Preferably, the imaging assembly includes an imaging assembly focusing assembly and an imaging assembly receiving assembly, wherein the imaging assembly includes four focusing lenses and a focusing assembly fixed support, the imaging assembly receiving assembly includes four regular polarizers, a fixed tray, a camera and a receiving assembly fixed support, the four focusing lenses in the focusing assembly are installed on the focusing assembly fixed support, the four regular polarizers are installed on the fixed tray, and the fixed tray and the camera are fixed to the receiving assembly fixed support, the polarization directions of the four regular polarizers are 0°, 45°, 90° and 135° respectively, and the four focusing lenses focus the four mixed elliptical polarized light from the multi-stage light splitting assembly through the four regular polarizers on the camera to form four interference fringe patterns in four regions on the camera at the same time, and the size of the four interference fringe patterns is adjusted by translating the imaging assembly receiving assembly through the oval slot features on the receiving assembly fixed support or the guide rails below the imaging assembly receiving assembly.

[0018] The part of polarized light emitted by the laser assembly passes through the light beam shaping filter assembly composed of the microscope and the filter assembly 4, the spherical light wave is formed by the shaping filter, and then the collimated part of the polarized light is formed by the light beam collimation assembly. After passing through the contrast adjustment assembly, the collimated part of the polarized light passes through the polarization light splitting assembly and is divided into P light and S light. The P light enters the reference light path and the S light enters the measurement light path. The P light enters the installation hole of the polarization light splitting fixed support and enters the reference light path. The P light entering the reference light path returns through the reference mirror and is converted into S light through the quarter-wave plate in the reference light path. Then, the S light passes through the polarization splitting prism and is converted into elliptical polarized light after passing through the quarter-wave plate in the imaging light path. The S light entering the measurement light path passes through the beam expander assembly (beam expander assembly front group + mirror assembly two + beam expander assembly rear group) and returns through the reflection of the measured optical system. The S light is converted into P light through the quarter-wave plate in the measurement light path and enters the quarter-wave plate in the imaging light path through the polarization splitting prism. The P light is converted into elliptical polarized light. The elliptical polarized light returned from the reference light path and the measurement light path enters the multi-stage light splitting assembly front group and the multi-stage light splitting assembly rear group in turn. The multi-stage light splitting assembly forms four mixed light of the reference light and the measurement light, which enters the imaging assembly focusing assembly and converges to the four regular polarizers in the imaging assembly receiving assembly. Four interference fringe patterns separated by a quarter of a wavelength are generated in four regions on the camera at the same time. The surface profile of the measured optical system can be calculated by calculation.

[0019] The present application has the following advantages compared with the prior art:

[0020] The multi-stage light splitting general polarizer dynamic interferometer of the present application overcomes the problem of the limitation of special cameras or inconsistency of multiple cameras by using a common single camera to realize dynamic interference measurement through a multi-stage light splitting assembly, an imaging assembly focusing assembly, and an imaging assembly receiving assembly. BRIEF DESCRIPTION OF DRAWINGS

[0021] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings:

[0022] Figure 1 Fig. 1 is a structural schematic diagram of a multi-stage light splitting general polarizer dynamic interferometer of the present application;

[0023] Figure 2 Fig. 2 is a schematic diagram of a light beam collimation assembly of the present application;

[0024] Figure 3 Fig. 3 is a schematic diagram of a contrast adjustment assembly of the present application;

[0025] Figure 4 Fig. 4 is a schematic diagram of a polarization light splitting assembly of the present application;

[0026] Figure 5 Fig. 5 is a schematic diagram of a front group of a beam expander assembly of the present application;

[0027] Figure 6 Fig. 6 is a schematic diagram of a multi-stage light splitting assembly of the present application;

[0028] Figure 7 Fig. 7 is a schematic diagram of a focusing assembly of an imaging assembly of the present application;

[0029] Figure 8 Fig. 8 is a schematic diagram of a receiving assembly of an imaging assembly of the present application.

[0030] Wherein, the mounting base plate 1, the laser assembly 2, the microscope 3, and the filter assembly 4 constitute a light beam shaping filter assembly, the light beam collimation assembly 5, the contrast focusing assembly 6, the mirror assembly one 7, the polarization light splitting assembly 8, the front group of the beam expander assembly 9, the mirror assembly two 12, the rear group of the beam expander assembly 14, 9 and 12 and 14 constitute the beam expander assembly, the front group of the multi-stage light splitting assembly 10 and the rear group of the multi-stage light splitting assembly 11 constitute the multi-stage light splitting assembly, the focusing assembly of the imaging assembly 13, the receiving assembly of the imaging assembly 15, 13 and 15 constitute the imaging assembly, and the window assembly 16. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below with reference to the accompanying drawings:

[0032] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned objectives, the present invention adopts the following technical solutions.

[0033] like Figure 1 As shown, the entire interferometer consists of a laser assembly 2, a beam shaping and filtering assembly (microscope 3 + filtering assembly 4), a beam collimating assembly 5, a contrast and focusing assembly 6, a polarization beam splitting assembly 8, a beam expanding assembly (beam expanding assembly front assembly 9 + reflector assembly 2 12 + beam expanding assembly rear assembly 14), a multi-stage beam splitting assembly (multi-stage beam splitting assembly front assembly 10 + multi-stage beam splitting assembly rear assembly 11), an imaging assembly (imaging assembly focusing assembly 13 + imaging assembly receiving assembly 15), and a window assembly 16. These components are all mounted on a mounting base 1.

[0034] The partially polarized light emitted by laser assembly 2 passes through a beam shaping and filtering assembly consisting of microscope 3 and filtering assembly 4. This shaping and filtering produces a spherical light wave, which is then collimated by beam collimation assembly 5 to form collimated partially polarized light. This light then passes through contrast adjustment assembly 6, where the contrast can be adjusted by rotating contrast adjustment assembly 6. After passing through contrast adjustment assembly 6, the collimated partially polarized light passes through polarization beam splitting assembly 8 and is split into P light and S light. The P light enters the reference optical path, while the S light enters the measurement optical path. The P light enters the reference optical path through mounting hole 8A-3 of polarization beam splitting fixture 8A. The P light entering the reference optical path returns through reference reflector 8B, is converted into S light through quarter-wave plate 8C, passes through polarization beam splitting prism 8D, enters mounting hole 8A-4 of polarization beam splitting fixture 8A, and is converted into elliptically polarized light through quarter-wave plate 8E of the imaging optical path. The S light entering the measurement optical path passes through the beam expander assembly (beam expander assembly front group 9 + reflector assembly 2 12 + beam expander assembly rear group 14) and then returns to the original path of the optical system under test. It is converted into P light by the quarter-wave plate 9C of the measurement optical path, passes through the polarization splitter prism 8D, enters the mounting hole 8A-4 of the polarization splitter fixing bracket 8A, and passes through the quarter-wave plate 8E of the imaging optical path to be converted into elliptically polarized light.

[0035] The mixed elliptically polarized light returned from the reference optical path and the measurement optical path enters the multi-stage spectroscopic assembly composed of the multi-stage spectroscopic assembly front group 10 and the multi-stage spectroscopic assembly rear group 1 in sequence, and then forms four paths of mixed elliptically polarized light, which enters the imaging assembly focusing assembly 13. The four paths of mixed elliptically polarized light are converged to the four conventional polarizers 15D, 15E, 15F, and 15G of the imaging assembly receiving assembly 15, and then four interference fringe patterns separated by a quarter wavelength are simultaneously generated in four areas on the camera 15B. The surface shape of the optical system under test can be solved by calculation.

[0036] As shown in FIG. 1, it is a schematic diagram of a light beam collimation assembly of a multi-stage spectropolarimeter dynamic interferometer of the present application. The collimation lens 5B is fixed on the collimation lens fixing support 5A by the compression ring 5C. The collimation lens fixing support 5A is adjusted so that the focal point of the collimation lens 5B coincides with the pinhole of the filter assembly, and the collimated light from the collimation lens 5B is parallel to the surface of the mounting substrate 1. Figure 2

[0037] As shown in FIG. 2, it is a schematic diagram of a contrast adjustment assembly of a multi-stage spectropolarimeter dynamic interferometer of the present application. The circular linear polarizer 6B is fixed on the circular linear polarizer fixing support 6A by the compression ring 6C. The circular linear polarizer 6B is not pressed tightly by the compression ring 6C. The contrast of the P light and S light from the polarization light splitting assembly 8 can be adjusted by rotating the circular linear polarizer 6B. Figure 3

[0038] As shown in FIG. 3, it is a schematic diagram of a polarization light splitting assembly of a multi-stage spectropolarimeter dynamic interferometer of the present application. The polarization light splitting prism 8D is installed in the square cavity of the polarization light splitting fixing support 8A. The reference light path quarter-wave plate 8C and the reference mirror 8B are installed in the mounting hole 8A-3 of the polarization light splitting fixing support 8A. The imaging light path quarter-wave plate 8E is installed in the mounting hole 8A-4 of the polarization light splitting fixing support 8A. The compression ring 8F is used for compression and fixation. The collimated polarized light from the contrast adjustment assembly 6 enters the light inlet hole 8A-1 of the polarization light splitting fixing support 8A and is split into P light and S light by the polarization light splitting prism 8D. The P light enters the mounting hole 8A-3 of the polarization light splitting fixing support 8A and enters the reference light path. The P light in the reference light path returns through the reference mirror 8B and is converted into S light by the reference light path quarter-wave plate 8C. The S light enters the mounting hole 8A-4 of the polarization light splitting fixing support 8A and is converted into elliptical polarized light by the imaging light path quarter-wave plate 8E. The S light enters the measurement light path and returns through the measured optical system. The returned light is converted into P light by the measurement light path quarter-wave plate 9C and enters the mounting hole 8A-4 of the polarization light splitting fixing support 8A through the polarization light splitting prism 8D. The returned light is converted into elliptical polarized light by the imaging light path quarter-wave plate 8E. The output from the polarization light splitting assembly 8 is the mixed elliptical polarized light composed of the returned light of the reference light path and the returned light of the measurement light path. Figure 4

[0039] As shown in FIG. 4, it is a schematic diagram of a polarization light splitting assembly of a multi-stage spectropolarimeter dynamic interferometer of the present application. The polarization light splitting prism 8D is installed in the square cavity of the polarization light splitting fixing support 8A. The reference light path quarter-wave plate 8C and the reference mirror 8B are installed in the mounting hole 8A-3 of the polarization light splitting fixing support 8A. The imaging light path quarter-wave plate 8E is installed in the mounting hole 8A-4 of the polarization light splitting fixing support 8A. The compression ring 8F is used for compression and fixation. The collimated polarized light from the contrast adjustment assembly 6 enters the light inlet hole 8A-1 of the polarization light splitting fixing support 8A and is split into P light and S light by the polarization light splitting prism 8D. The P light enters the mounting hole 8A-3 of the polarization light splitting fixing support 8A and enters the reference light path. The P light in the reference light path returns through the reference mirror 8B and is converted into S light by the reference light path quarter-wave plate 8C. The S light enters the mounting hole 8A-4 of the polarization light splitting fixing support 8A and is converted into elliptical polarized light by the imaging light path quarter-wave plate 8E. The S light enters the measurement light path and returns through the measured optical system. The returned light is converted into P light by the measurement light path quarter-wave plate 9C and enters the mounting hole 8A-4 of the polarization light splitting fixing support 8A through the polarization light splitting prism 8D. The returned light is converted into elliptical polarized light by the imaging light path quarter-wave plate 8E. The output from the polarization light splitting assembly 8 is the mixed elliptical polarized light composed of the returned light of the reference light path and the returned light of the measurement light path. Figure 5 ​​​Figure 1 shows a schematic diagram of the front beam expander assembly of a multi-stage beam splitting conventional polarizer dynamic interferometer according to the present invention. The measurement optical path quarter-wave plate 9C and focusing lens 9B are mounted on a focusing lens mounting bracket 9A. The measurement optical path quarter-wave plate 9C converts the S-light reflected from the optical system under test into P-light. The focusing lens 9B cooperates with the rear beam expander assembly 14 to increase the measurement aperture.

[0040] like Figure 6 The figure shows a schematic diagram of a multi-stage spectrometer assembly for a multi-stage spectrometer with a conventional polarizer. The multi-stage spectrometer assembly is composed of a multi-stage spectrometer front group 10 and a multi-stage spectrometer rear group 11. The multi-stage spectrometer front group semi-transparent and semi-reflective mirror 10B and the multi-stage spectrometer front group reflective mirror 10C are fixed to the multi-stage spectrometer front group bracket 10A, while the multi-stage spectrometer rear group semi-transparent and semi-reflective mirrors 11B and 11E and the multi-stage spectrometer rear group reflective mirrors 11B and 11D are fixed to the multi-stage spectrometer rear group bracket 11A. The mixed elliptically polarized light returning from the reference optical path and the measurement optical path enters the multi-stage spectrometer front group semi-transparent and semi-reflective mirror 10B, a portion of which passes through 10B and enters the multi-stage spectrometer rear group semi-transparent and semi-reflective mirror 11E, while a portion of which is reflected and enters the reflective surface of the multi-stage spectrometer front group reflective mirror 10C. The mixed elliptically polarized light entering the multi-stage beam splitting rear group semi-transparent and semi-reflective mirror 11E has a portion directly transmitted through the focusing lens 13B of the imaging assembly focusing assembly 13, while a portion is reflected by the multi-stage beam splitting rear group reflector 11D and then reflected into the focusing lens 13C of the imaging assembly focusing assembly 13. The mixed elliptically polarized light entering the reflective surface of the multi-stage beam splitting front group reflector 10C enters the multi-stage beam splitting rear group semi-transparent and semi-reflective mirror 11C for splitting, with a portion directly transmitted through the focusing lens 13D of the imaging assembly focusing assembly 13, while a portion is reflected by the multi-stage beam splitting rear group reflector 11B and then reflected into the focusing lens 13E of the imaging assembly focusing assembly 13. The output from the multi-stage beam splitting assembly is four-way mixed elliptically polarized light.

[0041] like Figure 7 Figure 1 is a schematic diagram of the imaging and focusing assembly of a multi-stage beam splitting conventional polarizer dynamic interferometer according to the present invention. Four focusing lenses 13B, 13C, 13D, and 13E are mounted on a focusing assembly mounting bracket 13A. These four focusing lenses 13B, 13C, 13D, and 13E focus the four paths of mixed elliptically polarized light split from the multi-stage beam splitting assembly onto an imaging assembly receiving assembly 15.

[0042] like Figure 8As shown, it is a schematic diagram of imaging assembly receiving assembly of a multi-stage light splitting conventional polarizer dynamic interferometer of the present application. Four conventional polarizers 15D, 15E, 15F, 15G are installed on a fixed tray 15C, and the fixed tray 15C and the camera 15B are fixed to the receiving assembly fixed support 15A. The polarization directions of the four conventional polarizers 15D, 15E, 15F, 15G are 45°, 0°, 90°, 135° respectively. Four focusing lenses 13B, 13C, 13D, 13E focus the four mixed elliptical polarized lights split from the multi-stage light splitting assembly through the four conventional polarizers 15D, 15E, 15F, 15G on the camera 15B respectively, and form four interference fringe patterns in four areas on the camera 15B. Through calculation, the surface shape of the measured optical system can be solved.

[0043] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A multi-stage splitting conventional polarizer dynamic interferometer, characterized in that: The invention comprises an installation base plate, on which a laser assembly, a microscope, a filter assembly, a beam collimation assembly, a contrast focusing assembly, a first reflector assembly, a polarization beam splitting assembly, a front group of a beam expander assembly, a second reflector assembly, a front group of a beam expander assembly, a rear group of a beam expander assembly, a front group of a multi-stage beam splitting assembly, a rear group of a multi-stage beam splitting assembly, an imaging assembly focusing assembly, an imaging assembly receiving assembly, and a window assembly are fixed in sequence.

2. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The microscope and the filter assembly constitute a beam shaping filter assembly, the second reflector assembly and the rear assembly of the beam expander assembly constitute a beam expander assembly, the front assembly of the multi-stage spectrometer assembly and the rear assembly of the multi-stage spectrometer assembly constitute a multi-stage spectrometer assembly, and the imaging assembly focusing assembly and the imaging assembly receiving assembly constitute an imaging assembly.

3. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The beam collimating assembly includes a pressure ring, a collimating lens and a collimating lens fixing bracket. The collimating lens fixing bracket is adjusted so that the focus of the collimating lens coincides with the pinhole of the filter assembly, and the collimated light emitted from the collimating lens is parallel to the surface of the mounting substrate.

4. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The contrast adjustment component includes a pressing ring, a circular linear polarizer and a circular linear polarizer fixing bracket; the contrast of the P light and the S light separated from the polarization splitting component can be adjusted by rotating the circular linear polarizer.

5. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The polarization splitting assembly includes a polarization splitting prism, a polarization splitting fixing bracket, a reference light path quarter wave plate, a reference reflector, an imaging light path quarter wave plate and a pressure ring; the polarization splitting prism is installed in the square cavity of the polarization splitting fixing bracket, and the reference light path quarter wave plate, the reference reflector and the imaging light path quarter wave plate are installed in the mounting hole of the polarization splitting fixing bracket.

6. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 5, characterized in that: The reference optical path quarter-wave plate is used to convert between P light and S light, and the imaging optical path quarter-wave plate is used to convert linearly polarized light into elliptically polarized light. The output from the polarization splitter assembly is a mixed elliptically polarized light synthesized by the light beam returned from the reference optical path and the light beam returned from the measurement optical path.

7. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The beam expansion assembly includes a front beam expansion group and a rear beam expansion group. The front beam expansion assembly includes a quarter-wave plate for the measurement optical path, a focusing lens, and a focusing lens fixing bracket. The quarter-wave plate for the measurement optical path is used to convert the S light returned from the original reflection path of the optical system under test into P light. The focusing lens cooperates with the rear beam expansion assembly to increase the measurement aperture.

8. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The multi-level beam splitting component includes a multi-level beam splitting front group and a multi-level beam splitting rear group. A multi-level beam splitting front group semi-transparent and semi-reflective mirror and a multi-level beam splitting front group reflector are fixed on the multi-level beam splitting front group bracket, and the semi-transparent and semi-reflective mirror and the reflector are installed at 45° to the optical axis of the light beam. Two multi-level beam splitting rear group semi-transparent and semi-reflective mirrors and two multi-level beam splitting rear group reflectors are fixed on the multi-level beam splitting rear group bracket, and the semi-transparent and semi-reflective mirrors and the reflector are installed at 45° to the optical axis of the light beam. The output from the multi-level beam splitting component is four-way mixed elliptically polarized light.

9. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 1, characterized in that: The imaging assembly includes an imaging assembly focusing assembly and an imaging assembly receiving assembly, wherein the imaging assembly includes four focusing lenses and a focusing assembly fixing bracket, and the imaging assembly receiving assembly includes four conventional polarizers, a fixing tray, a camera and a receiving assembly fixing bracket.

10. The multi-stage beam splitting conventional polarizer dynamic interferometer according to claim 9, characterized in that: The four focusing lenses in the focusing assembly are installed on the focusing assembly fixing bracket, and the four conventional polarizers are installed on the fixing tray. The fixing tray and the camera are fixed to the receiving assembly fixing bracket. The polarization directions of the four conventional polarizers are 0°, 45°, 90° and 135° respectively. The four focusing lenses focus the four mixed elliptically polarized lights separated from the multi-level splitting assembly onto the camera through the four conventional polarizers, and four interference fringe patterns in four areas are formed on the camera at the same time. The size of the four interference fringe patterns is adjusted by translating the imaging assembly receiving assembly through the oval groove feature on the receiving assembly fixing bracket or the guide rail under the imaging assembly receiving assembly.

Images