Transverse shear wavefront detection system and method based on screen shooting

Abstract

The invention provides a transverse shear wavefront detection system and method based on screen shooting, and the system comprises a shear plate which is used for enabling a wavefront to be detected to generate shear interference fringes in two orthogonal directions; the diffuser screen is arranged behind the shear plate along the light path propagation direction and is used for displaying the interference fringe image sheared by the shear plate; the image acquisition unit is used for acquiring an interference fringe image of the diffuser screen; and the data processing unit is in communication connection with the image acquisition unit and is used for calculating to-be-measured wavefront information. The wavefront beam to be measured does not need to be shrunk to the size of the target surface of the camera, so that the measurement difficulty of the collimator is reduced, and the influence of aberration of a beam shrunk device on the measurement accuracy is also reduced. Compared with the prior art, the method has the advantages that the problems that the wavefront aberration of the collimator is difficult to directly measure and the aberration component and size cannot be accurately given are solved, quantitative measurement of the wavefront aberration of the collimator is realized, and the measurement accuracy and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical precision measurement wavefront detection, and particularly relates to a lateral shear wavefront detection system and method based on screen shooting. Background Art

[0002] In the process of processing optical elements and aligning optical systems, the quality of optical systems will deteriorate due to material inhomogeneity, processing and assembly errors, etc. Whether in the field of astronomical research, interferometric measurement or flow field measurement, the problem of optical system aberration is faced. In order to ensure the alignment of optical systems or the processing accuracy of mirror surfaces, a collimator light source is usually required as a reference. The collimator can be directed at the interferometer during processing and alignment to minimize the system aberration. However, during use and transportation, due to vibration and temperature effects, the aberration of the collimator becomes larger. At this time, it becomes quite difficult to detect the aberration of the entire system with an interferometer.

[0003] Traditional wavefront detectors include Hartmann wavefront sensors, shear interferometers, and pyramid wavefront sensors, etc. Due to the principle and structural limitations of wavefront sensors, the measurement of the collimator wavefront usually requires a beam expander to reduce the beam to the size of the camera target surface, and then the wavefront is detected by a wavefront detector. However, the processing and alignment of the beam expander usually introduce its own aberration, and the processing and alignment of the beam expander also require a collimator light source as a reference. Therefore, its own aberration cannot be traced back either.

[0004] Most other methods for measuring the wavefront of a collimator are qualitative measurements. The simplest method for judging the parallelism of a light source is to observe the change in the spot size of the light source at a long distance. Since the shape and size of the spot of an ideal plane light do not change during transmission, if it is observed that the spot size of the plane light source becomes larger or smaller during transmission, it is judged that the light source carries defocus aberration. In the laboratory, a single shear plate is usually used to observe the shape of the interference fringes with the naked eye. Since the shear plate has a wedge angle, the light source will only show straight fringes perpendicular to the shear direction under ideal conditions. If the rotation of the fringes is observed, it is considered that there may be defocus or astigmatism, and the bending of the fringes is considered as spherical aberration or coma. Another method for measuring the parallelism of a light source is the pentaprism method. Due to the characteristic that the incident and outgoing light of the pentaprism always remain perpendicular, the pentaprism can be used to perform single-point sampling on a certain line of the wavefront and measure the spot offset in the direction perpendicular to the outgoing light with an optical axis measurement system to qualitatively judge the parallelism of the light source. This type of method can only qualitatively judge that the system has low-order aberrations and cannot accurately give the type and magnitude of the aberrations. All optical system processing and alignment require the light source of the collimator as a reference, but the collimator is also an optical system. Measuring the aberration of the collimator by beam reduction will introduce the aberration of the beam reducer, making it difficult to separate the aberration of the light source to be measured from the aberration of the beam reducer. Only qualitative determination of the type of optical aberration can be made by observing with the naked eye through a shear plate or the pentaprism method, and the magnitude of the aberration cannot be accurately given. Therefore, the existing technology lacks a method for quantitatively measuring the static wavefront aberration of a collimator without beam reduction.

[0005] Therefore, the existing technology still needs to be further developed. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies and provide a lateral shear wavefront detection system and method based on screen shooting to solve the problems existing in the existing technology.

[0007] To achieve the above technical purpose, according to the first aspect of the present invention, the present invention provides a lateral shear wavefront detection system based on screen shooting, including: A shear plate for generating shear interference fringes of the wavefront to be measured in two orthogonal directions; A scattering screen arranged behind the shear plate along the optical path propagation direction for displaying the interference fringe image sheared by the shear plate; An image acquisition unit for acquiring the interference fringe image of the scattering screen; A data processing unit communicatively connected to the image acquisition unit for calculating the wavefront information to be measured.

[0008] Specifically, the shear plate includes a first shear plate and a second shear plate; The first shear plate is used to generate shear interference fringes of the wavefront to be measured in the first lateral shear direction, and the second shear plate is used to generate shear interference fringes of the wavefront to be measured in the second lateral shear direction; The second transverse shear direction is orthogonal to the first transverse shear direction.

[0009] Specifically, the scattering screen includes a first scattering screen and a second scattering screen; The first scattering screen is arranged behind the first shear plate along the optical path propagation direction and is located in a plane perpendicular to the first transverse shear direction, and is used to display the interference fringe image after the first shear plate performs shearing; The second scattering screen is arranged behind the second shear plate along the optical path propagation direction and is located in a plane perpendicular to the second transverse shear direction, and is used to display the interference fringe image after the second shear plate performs shearing.

[0010] Specifically, the image acquisition unit includes a first image acquisition unit and a second image acquisition unit; The first image acquisition unit is used to acquire the interference fringe image of the first scattering screen; The second image acquisition unit is used to acquire the interference fringe image of the second scattering screen.

[0011] Specifically, the first image acquisition unit includes a first camera and a first lens. The first lens is installed on the first camera. The imaging optical axis of the first lens is perpendicular to the surface of the first scattering screen, and the target surface of the first camera covers the interference fringe area of the first scattering screen.

[0012] Specifically, the second image acquisition unit includes a second camera and a second lens. The second lens is installed on the second camera. The imaging optical axis of the second lens is perpendicular to the surface of the second scattering screen, and the target surface of the second camera covers the interference fringe area of the second scattering screen.

[0013] Specifically, the first shear plate and the second shear plate are wedge-shaped optical flats. An interferometer is used to pre-calibrate the tilt optical path difference information generated by the wedge angle of the wedge-shaped optical flat and store it in the data processing unit.

[0014] According to the second aspect of the present invention, there is provided a method for detecting a transverse shear wavefront based on screen shooting, including: S100. Use a shear plate to perform transverse shearing on the wavefront to be measured in two orthogonal directions to generate shear interference fringes; S200. Project the shear interference fringes onto a scattering screen to form an interference fringe image; S300. Acquire the interference fringe image on the scattering screen; S400. Calculate the wavefront information to be measured according to the interference fringe image.

[0015] Specifically, the shear interference fringes include the slope information of the wavefront to be measured and the optical path difference information caused by the wedge angle of the shear plate.

[0016] Specifically, the method for calculating the wavefront information to be measured includes: Unwrap the shearing interference fringes to eliminate phase jumps, obtain the equal-inclination interference component of the optical path difference information, subtract the equal-inclination interference component caused by the wedge angle of the shear plate, and then use the wavefront reconstruction algorithm to convert the processed slope information into wavefront phase.

[0017] Beneficial effects: The present invention provides a lateral shearing wavefront detection system and method based on screen shooting. By using a shear plate, the wavefront to be measured generates shearing interference fringes in two orthogonal directions, projects the interference fringes onto a scattering screen, then acquires the interference fringe image through an image acquisition unit, and finally obtains the wavefront phase information to be measured by a data processing unit. It is not necessary to reduce the wavefront to be measured to the size of the camera target surface, which reduces the measurement difficulty of the collimator and also reduces the influence of the aberration of the beam expander on the measurement accuracy. Compared with the prior art, it solves the problems of difficulty in directly measuring the wavefront aberration of the collimator itself, and inability to accurately give the aberration components and magnitudes, realizes the quantitative measurement of the wavefront aberration of the collimator, and improves the measurement accuracy and efficiency. Description of the drawings

[0018] Figure 1 is a schematic diagram of the composition of the lateral shearing wavefront detection system based on screen shooting provided in the specific embodiment of the present invention; Figure 2 is a schematic diagram of the optical path of the lateral shearing wavefront detection system based on screen shooting provided in the specific embodiment of the present invention; Figure 3 is a flowchart of the lateral shearing wavefront detection method based on screen shooting provided in the specific embodiment of the present invention; Among them, the reference numerals of the above drawings are as follows: 1. First shear plate; 2. First scattering screen; 3. First lens; 4. First camera; 5. Second shear plate; 6. Second scattering screen; 7. Second lens; 8. Second camera; 100. Shear plate; 200. Scattering screen; 300. Image acquisition unit; 400. Data processing unit. Specific embodiments

[0019] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application. In addition, the directional terms mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only references to the directions in the drawings. Therefore, the directional terms used are for illustration rather than limitation of the present invention.

[0020] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments.

[0021] Embodiment 1 Please refer to Figure 1 , this embodiment provides a lateral shear wavefront detection system based on screen shooting, including a shear plate 100, a scattering screen 200, an image acquisition unit 300, and a data processing unit 400, which realizes the measurement of the static wavefront aberration of a collimator, and solves the problem that when using a traditional wavefront detector for wavefront detection, the wavefront to be measured needs to be reduced to the detector scale, which will introduce the aberration of the beam expander and make it difficult to distinguish the collimator aberration from the beam expander aberration. At the same time, it solves the problems that using the fringe observation method of the shear plate 100 and the optical axis observation method of the pentaprism can only qualitatively judge the type of wavefront aberration and cannot quantitatively give the specific value of the aberration. The present invention can not only give the type of aberration but also quantitatively analyze the magnitude of the aberration.

[0022] See Figure 2 , the shear plate 100 is used to generate shear interference fringes of the wavefront to be measured in two orthogonal directions. The shear plate 100 includes a first shear plate 1 and a second shear plate 5. The first shear plate 1 is used to generate shear interference fringes of the wavefront to be measured in the first lateral shear direction, and the second shear plate 5 is used to generate shear interference fringes of the wavefront to be measured in the second lateral shear direction. The second lateral shear direction is orthogonal to the first lateral shear direction. The first shear plate 1 and the second shear plate 5 are wedge-shaped optical flats, and the tilt optical path difference information generated by the wedge angle of the wedge-shaped optical flat is pre-calibrated and stored in the data processing unit 400 using an interferometer.

[0023] It can be understood that the front and rear surfaces of the shear plate 100 have a wedge angle. The wavefront will form light with a certain included angle through the reflection of the front and rear surfaces, and then interference will occur in the overlapping part. The interference fringes are a kind of periodic fringes with bright and dark intersections.

[0024] Further, see Figure 2 , the scattering screen 200 is arranged behind the shear plate 100 along the optical path propagation direction and is used to display the interference fringe image sheared by the shear plate 100. The scattering screen 200 includes a first scattering screen 2 and a second scattering screen 6. The first scattering screen 2 is arranged behind the first shear plate 1 along the optical path propagation direction and is located in a plane perpendicular to the first lateral shear direction, and is used to display the interference fringe image sheared by the first shear plate 1. The second scattering screen 6 is arranged behind the second shear plate 5 along the optical path propagation direction and is located in a plane perpendicular to the second lateral shear direction, and is used to display the interference fringe image sheared by the second shear plate 5.

[0025] It can be understood that, as Figure 2As shown, in this embodiment, the first transverse shear direction is the X direction, the second transverse shear direction is the Y direction, the plane perpendicular to the first transverse shear direction is the XOZ plane, and the plane perpendicular to the second transverse shear direction is the XOY plane. That is, the first shear plate 1 causes a certain amount of shear of the wavefront to be measured in the X direction; the second shear plate 5 causes a certain amount of shear of the wavefront to be measured in the Y direction; the first scattering screen 2 is placed at a certain distance behind the first shear plate 1 and is parallel to the XOZ plane, so that the interference fringes are imaged thereon; the second scattering screen 6 is placed at a certain distance behind the second shear plate 5 and is parallel to the XOY plane, so that the interference fringes are imaged thereon, thereby realizing high-precision synchronous detection of the wavefront in two orthogonal dimensions. Among them, the X-direction shear combined with the XOZ-plane scattering screen 200 can obtain the transverse phase gradient information of the wavefront, and the Y-direction shear combined with the XOY-plane scattering screen 200 effectively separates the longitudinal aberration, significantly improving the dimensional integrity and measurement resolution of the wavefront reconstruction. At the same time, the specific spatial arrangement of the scattering screen 200 optimizes the imaging quality of the interference fringes, enabling the system to have both multi-degree-of-freedom detection capabilities and anti-environmental interference characteristics.

[0026] Preferably, the first scattering screen 2 is placed at a certain distance behind the first shear plate 1, and this distance can be set to 10 cm - 30 cm. Similarly, the distance range of the second scattering screen 6 placed behind the second shear plate 5 can also be set to 10 cm - 30 cm.

[0027] See Figure 2 , in this embodiment, the image acquisition unit 300 is used to acquire the interference fringe images of the scattering screen 200. The image acquisition unit 300 includes a first image acquisition unit and a second image acquisition unit. The first image acquisition unit is used to acquire the interference fringe images of the first scattering screen 2. The second image acquisition unit is used to acquire the interference fringe images of the second scattering screen 6. The first image acquisition unit includes a first camera 4 and a first lens 3. The first lens 3 is installed on the first camera 4. The imaging optical axis of the first lens 3 is perpendicular to the surface of the first scattering screen 2, and the target surface of the first camera 4 covers the interference fringe area of the first scattering screen 2. The second image acquisition unit includes a second camera 8 and a second lens 7. The second lens 7 is installed on the second camera 8. The imaging optical axis of the second lens 7 is perpendicular to the surface of the second scattering screen 6, and the target surface of the second camera 8 covers the interference fringe area of the second scattering screen 6.

[0028] See Figure 1 , in this embodiment, the data processing unit 400 is communicatively connected to the image acquisition unit 300 and is used to calculate the wavefront information to be measured. The data processing unit 400 can be a computer or a dedicated data processing device, which has sufficient computing power and storage space, is used to receive the interference fringe image data transmitted by the image acquisition unit 300, and calculates the phase information of the wavefront to be measured through a wavefront reconstruction algorithm.

[0029] Furthermore, the data processing unit 400 can obtain the phase information of the wavefront to be measured by analyzing the slopes of the wavefront in two orthogonal directions from the interference fringe image information recorded by the first camera 4 and the second camera 8 and then integrating them.

[0030] It can be understood that the shearing interference fringes simultaneously contain the slope information of the wavefront to be measured and the optical path difference information caused by the certain included angle, i.e., the wedge angle, between the front and rear surfaces of the shear plate 100. When the shear plate 100 is processed, an interferometer is required to detect the surface shape difference between the front and rear surfaces of the shear plate 100, and this surface shape difference is mainly the tilt amount caused by the wedge angle of the shear plate 100. After the data processing unit 400 unwraps the interference fringes and subtracts the tilt component caused by the shear plate 100 measured by the interferometer, the slope of the wavefront to be measured is obtained. Then, the wavefront restoration algorithm can convert the wavefront slope information in two orthogonal directions into the wavefront information to be measured. According to the above solution, the present invention uses the scattering screen 200 to receive the interference fringe image, and uses a camera plus a lens to photograph the interference fringes on the scattering screen 200, and can completely record the wavefront information to be measured without beam shrinking, further improving the accuracy of wavefront measurement.

[0031] See Figure 2 , in this embodiment, the working principle of the lateral shearing wavefront detection system based on screen shooting is as follows: The wavefront to be measured first passes through the first shear plate 1, and shearing interference fringes are generated in the first lateral shearing direction. These interference fringes are projected onto the first scattering screen 2 to form a visible interference fringe image. The first image acquisition unit acquires the interference fringe image on the first scattering screen 2 and transmits the image data to the data processing unit 400. At the same time, the wavefront to be measured also passes through the second shear plate 5, and shearing interference fringes are generated in the second lateral shearing direction. These interference fringes are projected onto the second scattering screen 6 to form a visible interference image. The second image acquisition unit acquires the interference fringe image on the second scattering screen 6 and transmits the image data to the data processing unit 400.

[0032] Furthermore, after the data processing unit 400 receives the interference fringe images in two directions, it first unwraps the interference fringes to eliminate the phase jump and obtains the equal inclination interference component of the optical path difference information. Then, the data processing unit 400 subtracts the equal inclination interference component caused by the wedge angle of the shear plate 100 (this information has been pre-calibrated and stored in the data processing unit) from it. Finally, the data processing unit 400 uses the wavefront restoration algorithm to convert the processed slope information into the wavefront phase, thereby obtaining the complete wavefront information to be measured.

[0033] It should be noted here that the lateral shear wavefront detection system based on screen shooting in this embodiment has the characteristics of simple structure, convenient operation and high measurement accuracy. By simultaneously performing wavefront shearing in two orthogonal directions, the complete slope information of the wavefront in the two directions can be obtained, so as to realize the comprehensive detection of the wavefront. The use of the scattering screen enables the interference fringes to be directly displayed, which is convenient for observation and acquisition. The interference fringe image collected by the image acquisition unit contains rich wavefront information. The data processing unit can extract accurate wavefront phase information from it through a special algorithm, without reducing the measured wavefront to the size of the camera target surface, reducing the measurement difficulty of the collimator and also reducing the influence of the aberration of the beam expander on the measurement accuracy. Compared with the prior art, it solves the problems of difficult direct measurement of the wavefront aberration of the collimator itself and inability to accurately give the aberration components and magnitudes, realizes the quantitative measurement of the wavefront aberration of the collimator, and improves the accuracy and efficiency of the measurement.

[0034] Embodiment 2 Please refer to Figure 3 , this embodiment provides a lateral shear wavefront detection method based on screen shooting, which specifically includes the following steps: S100. Use the shear plate 100 to perform lateral shearing on the measured wavefront in two orthogonal directions to generate shear interference fringes; S200. Project the shear interference fringes onto the scattering screen 200 to form an interference fringe image; S300. Collect the interference fringe image on the scattering screen 200; S400. Calculate the measured wavefront information according to the interference fringe image.

[0035] It can be understood that the present invention records the shear interference information in two orthogonal directions by means of screen shooting. This method does not require beam reduction of the wavefront, reduces the influence of the beam expander aberration on wavefront detection, can not only give the types of aberrations but also quantitatively analyze the magnitudes of aberrations, and greatly improves the usability and reliability of this application.

[0036] Furthermore, in step S100, the shear interference fringes include the slope information of the measured wavefront and the optical path difference information caused by the wedge angle of the shear plate 100. Specifically, use the first shear plate 1 to shear the measured wavefront in the first lateral shear direction to generate shear interference fringes in the first lateral shear direction; at the same time, use the second shear plate 5 to shear the measured wavefront in the second lateral shear direction to generate shear interference fringes in the second lateral shear direction. The first lateral shear direction and the second lateral shear direction are perpendicular to each other to form an orthogonal relationship, so that the complete slope information of the wavefront in the two orthogonal directions can be obtained.

[0037] Further, in step S200, the shearing interference fringes in the first direction are projected onto the first scattering screen 2 to form a first interference fringe image; the shearing interference fringes in the second direction are projected onto the second scattering screen 6 to form a second interference fringe image. The first scattering screen 2 is located in a plane perpendicular to the first transverse shearing direction, and the second scattering screen 6 is located in a plane perpendicular to the second transverse shearing direction. The material of the scattering screen 200 can be a material with scattering characteristics, which can clearly display the interference fringes projected onto it.

[0038] Further, in step S300, the first image acquisition unit is used to acquire the interference fringe image on the first scattering screen 2; the second image acquisition unit is used to acquire the interference fringe image on the second scattering screen 6. The first image acquisition unit includes a first camera 4 and a first lens 3. The imaging optical axis of the first lens 3 is perpendicular to the surface of the first scattering screen 2, and the target surface of the first camera 4 covers the interference fringe area of the first scattering screen 2. The second image acquisition unit includes a second camera 8 and a second lens 7. The imaging optical axis of the second lens 7 is perpendicular to the surface of the second scattering screen 6, and the target surface of the second camera 8 covers the interference fringe area of the second scattering screen 6. The image acquisition unit 300 transmits the acquired interference fringe image data to the data processing unit 400.

[0039] Further, in step S400, the method for calculating the wavefront information to be measured includes: unwrapping the shearing interference fringes to eliminate phase jumps, obtaining the isoclinic interference component of the optical path difference information, subtracting the isoclinic interference component caused by the wedge angle of the shear plate 100, and then using a wavefront reconstruction algorithm to convert the processed slope information into a wavefront phase. The specific steps are as follows: Step 1: The data processing unit 400 first preprocesses the acquired interference fringe image, including operations such as image filtering and enhancement to improve the image quality; Step 2: Unwrap the phase of the processed interference fringe image to eliminate phase jumps and obtain a continuous phase distribution; Step 3: Extract the isoclinic interference component from the phase distribution and subtract the isoclinic interference component caused by the wedge angle of the shear plate 100 (this information has been pre-calibrated by the interferometer and stored in the data processing unit); Step 4: Use a wavefront reconstruction algorithm, such as the integral method, the modal method, the zonal method, etc., to convert the processed slope information into a wavefront phase, so as to obtain the complete wavefront information to be measured.

[0040] It should be further noted that the shear plate utilizes the reflection of its front and back surfaces to copy the wavefront to be measured into two. The included angle of the shear plate causes the copied wavefronts to be transmitted at a certain angle with respect to the original wavefront. The scattering screen is used to receive the lateral shear interference fringes of the two copied wavefronts, and the camera plus lens is used to record the spatial separation information of the interference fringes on the scattering screen. Since the interference fringes in a single shear direction carry both the tilt information of the front and back surfaces of the shear plate and the gradient information of the wavefront to be measured perpendicular to the shear direction. Therefore, by performing shear interference on the wavefront to be measured in two orthogonal directions, using the data processing unit 400 to unwrap the interference fringes, and then removing the equal-inclination interference component brought by the wedge angle of the shear plate (this component can be obtained by measuring the surface shapes of the front and back surfaces of the shear plate with an interferometer), the wavefront gradients in two orthogonal directions of the wavefront to be measured can be obtained. The process from wavefront gradient information to wavefront phase information is called wavefront reconstruction, and wavefront reconstruction algorithms such as the integration method, the modal method, or the zonal method can be used to perform reconstruction processing on the measured wavefront gradient information.

[0041] It should be noted here that the method for lateral shear wavefront detection based on screen shooting in this embodiment has the characteristics of simple operation and high measurement accuracy. By simultaneously performing wavefront shear in two orthogonal directions, the complete slope information of the wavefront in the two directions can be obtained, thereby realizing the comprehensive detection of the wavefront. The use of the scattering screen enables the interference fringes to be directly displayed, facilitating observation and acquisition. The interference fringe image collected by the image acquisition unit contains rich wavefront information. The data processing unit can extract accurate wavefront phase information from it through a dedicated algorithm, without reducing the wavefront to be measured to the size of the camera target surface, reducing the measurement difficulty of the collimator while also reducing the influence of the aberration of the beam expander on the measurement accuracy. Compared with the prior art, it solves the problems of difficulty in directly measuring the wavefront aberration of the collimator itself and being unable to accurately give the aberration components and magnitudes, realizes the quantitative measurement of the wavefront aberration of the collimator, and improves the accuracy and efficiency of the measurement.

[0042] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0044] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification as long as such a combination does not exist in contradiction.

[0045] The specific embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A lateral shear wavefront detection system based on screen shooting, characterized in that Comprising: A shear plate (100) for generating shear interference fringes of a wavefront to be measured in two orthogonal directions; A scattering screen (200) arranged behind the shear plate (100) along the optical path propagation direction for displaying the interference fringe image sheared by the shear plate (100); An image acquisition unit (300) for acquiring the interference fringe image of the scattering screen (200); A data processing unit (400) communicatively connected to the image acquisition unit (300) for calculating the wavefront information to be measured.

2. The lateral shear wavefront detection system based on screen capture according to claim 1, wherein The shear plate (100) includes a first shear plate (1) and a second shear plate (5); The first shear plate (1) is used for generating shear interference fringes of the wavefront to be measured in a first lateral shear direction, and the second shear plate (5) is used for generating shear interference fringes of the wavefront to be measured in a second lateral shear direction; The second lateral shear direction is orthogonal to the first lateral shear direction.

3. The lateral shear wavefront detection system based on screen capture according to claim 2, characterized in that, The scattering screen (200) includes a first scattering screen (2) and a second scattering screen (6); The first scattering screen (2) is arranged behind the first shear plate (1) along the optical path propagation direction and is located in a plane perpendicular to the first lateral shear direction for displaying the interference fringe image sheared by the first shear plate (1); The second scattering screen (6) is arranged behind the second shear plate (5) along the optical path propagation direction and is located in a plane perpendicular to the second lateral shear direction for displaying the interference fringe image sheared by the second shear plate (5).

4. The lateral shear wavefront detection system based on screen capture according to claim 3, wherein The image acquisition unit (300) includes a first image acquisition unit and a second image acquisition unit; The first image acquisition unit (300) is used for acquiring the interference fringe image of the first scattering screen (2); The second image acquisition unit is used for acquiring the interference fringe image of the second scattering screen (6).

5. The lateral shear wavefront detection system based on screen capture according to claim 4, wherein The first image acquisition unit includes a first camera (4) and a first lens (3). The first lens (3) is mounted on the first camera (4). The imaging optical axis of the first lens (3) is perpendicular to the surface of the first scattering screen (2), and the target surface of the first camera (4) covers the interference fringe area of the first scattering screen (2).

6. The lateral shear wavefront detection system based on screen capture according to claim 5, characterized in that The second image acquisition unit includes a second camera (8) and a second lens (7). The second lens (7) is mounted on the second camera (8). The imaging optical axis of the second lens (7) is perpendicular to the surface of the second scattering screen (6), and the target surface of the second camera (8) covers the interference fringe area of the second scattering screen (6).

7. The lateral shear wavefront detection system based on screen capture according to claim 2, characterized in that The first shear plate (1) and the second shear plate (5) are wedge-shaped optical flats. The tilt optical path difference information generated by the wedge angle of the wedge-shaped optical flat is pre-calibrated by an interferometer and stored in the data processing unit (400).

8. A method for detecting a lateral shear wavefront based on screen shooting, characterized in that, Comprising: S100. Transversely shear the wavefront to be measured in two orthogonal directions by using the shear plate (100) to generate shear interference fringes; S200. Project the shear interference fringes onto the scattering screen (200) to form an interference fringe image; S300. Acquire the interference fringe image on the scattering screen (200); S400. Calculate the wavefront information to be measured according to the interference fringe image.

9. The method for detecting a lateral shear wavefront based on screen capture according to claim 8, wherein, The shearing interference fringes include the slope information of the wavefront to be measured and the optical path difference information caused by the wedge angle of the shearing plate (100).

10. The method for detecting a lateral shear wavefront based on screen shooting according to claim 9, wherein, The method for calculating the wavefront information to be measured includes: Unwrapping the shearing interference fringes to eliminate phase jumps, obtaining the equal-inclination interference component of the optical path difference information, subtracting the equal-inclination interference component caused by the wedge angle of the shearing plate (100), and then using a wavefront reconstruction algorithm to convert the processed slope information into a wavefront phase.

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