A transverse shear wavefront detection system and method based on screen shooting

Abstract

The present invention provides a transverse shear wavefront detection system and method based on screen shooting, wherein the system includes: a shear plate, which is used to generate shear interference fringes in two orthogonal directions on the wavefront to be measured; a scattering screen, which is arranged behind the shear plate along the propagation direction of the light path, and is used to display the interference fringe image after shearing by the shear plate; an image acquisition unit, which is used to acquire the interference fringe image of the scattering screen; and a data processing unit, which is in communication with the image acquisition unit and is used to calculate the information of the wavefront to be measured. The present invention does not need to shrink the wavefront to be measured to the size of the camera target surface, which reduces the difficulty of measuring the collimator and also reduces the influence of the aberration of the collimator on the measurement accuracy. Compared with the existing technology, it solves the problem of difficulty in directly measuring the wavefront aberration of the collimator itself and the inability to accurately give the aberration component and size, and realizes the quantitative measurement of the wavefront aberration of the collimator, thereby improving the accuracy and efficiency of the measurement.

Description

Technical Field

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

[0002] During the processing of optical components and the assembly of optical systems, material inhomogeneity, processing and assembly errors, and other factors can cause the quality of the optical system to deteriorate. Whether in the fields of astronomical research, interferometry, or flow field measurement, optical system aberrations are a common problem. To ensure the assembly of optical systems or the machining accuracy of mirrors, a collimator light source is usually required as a reference. During processing and assembly, the collimator can be used to minimize the system's aberrations by pointing it at the interferometer. However, during use and transportation, the collimator's aberrations increase due to vibration and temperature, making it quite difficult to detect the aberrations of the entire system using an interferometer.

[0003] Traditional wavefront detectors include Hartmann wavefront sensors, shearing interferometers, and pyramid wavefront sensors. Due to the principles and structural limitations of wavefront sensors, measuring collimator wavefronts typically requires a beam reducer to shrink the beam to the size of the camera target before detecting it using a wavefront detector. However, the machining and alignment of the beam reducer often introduces its own aberrations, and the machining and alignment of the beam reducer also require a collimator light source as a reference, making it impossible to trace its own aberrations.

[0004] Most other methods for measuring the wavefront of a collimator are qualitative measurements. The simplest way to determine the parallelism of a light source is to observe the change in the light source spot size from a distance. Since the spot shape and size of ideal plane light do not change during transmission, if the spot size of a plane light source is observed to increase or decrease during transmission, it is determined that the light source carries defocus aberration. Laboratories usually use a single shear plate to observe the interference fringe morphology with the naked eye. Because the shear plate has a wedge angle, the light source ideally only produces straight fringes perpendicular to the shear direction. If the fringes are observed to rotate, it may be considered defocus or astigmatism, and the curvature of the fringes may be considered spherical aberration or coma. Another method for measuring the parallelism of a light source is the pentaprism method. Since the incident and outgoing light of the pentaprism are always perpendicular, the pentaprism can be used to perform single-point sampling on a certain line of the wavefront. After perpendicular to the outgoing direction, the optical axis measurement system is used to measure the spot offset to qualitatively determine the parallelism of the light source. This type of method can only qualitatively determine whether the system has low-order aberrations and cannot accurately determine the type and size of the aberration. All optical system fabrication and assembly require a collimator light source as a reference. However, collimators are also optical systems. Measuring collimator aberrations through beam reduction introduces aberrations from the beam reducer, making it difficult to separate the aberrations of the measured light source from those of the beam reducer. Visual observation with a shear plate or pentaprism can only qualitatively determine the type of optical aberration, but cannot accurately determine the magnitude of the aberration. Therefore, the existing technology lacks a method for quantitatively measuring static wavefront aberrations in collimators without beam reduction.

[0005] Therefore, the existing technology 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 prior art.

[0007] To achieve the above technical objectives, according to a first aspect of the present invention, a transverse shear wavefront detection system based on screen shooting is provided, comprising:

[0008] A shear plate is used to generate shear interference fringes in two orthogonal directions on the wavefront to be measured;

[0009] A scattering screen is arranged behind the shear plate along the propagation direction of the light path and is used to display the interference fringe image after the shear plate shears;

[0010] An image acquisition unit, configured to acquire an interference fringe image of the scattering screen;

[0011] The data processing unit is in communication with the image acquisition unit and is used to calculate the wavefront information to be measured.

[0012] Specifically, the shear plate includes a first shear plate and a second shear plate;

[0013] The first shear plate is used to cause the wavefront to be measured to generate shear interference fringes in a first transverse shear direction, and the second shear plate is used to cause the wavefront to be measured to generate shear interference fringes in a second transverse shear direction;

[0014] The second transverse shear direction is orthogonal to the first transverse shear direction.

[0015] Specifically, the scattering screen includes a first scattering screen and a second scattering screen;

[0016] The first scattering screen is arranged behind the first shear plate along the propagation direction of the light path and is located in a plane perpendicular to the first transverse shearing direction, and is used to display the interference fringe image after shearing by the first shear plate;

[0017] The second scattering screen is arranged behind the second shear plate along the light propagation direction and is located in a plane perpendicular to the second transverse shearing direction, and is used to display the interference fringe image after shearing by the second shear plate.

[0018] Specifically, the image acquisition unit includes a first image acquisition unit and a second image acquisition unit;

[0019] The first image acquisition unit is used to acquire the interference fringe image of the first scattering screen;

[0020] The second image acquisition unit is used to acquire the interference fringe image of the second scattering screen.

[0021] Specifically, the first image acquisition unit includes a first camera and a first lens, the first lens is mounted 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.

[0022] Specifically, the second image acquisition unit includes a second camera and a second lens, the second lens is mounted 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.

[0023] Specifically, the first shear plate and the second shear plate are wedge-shaped optical plates, and the tilt optical path difference information generated by the wedge angles of the wedge-shaped optical plates is pre-calibrated using an interferometer and stored in the data processing unit.

[0024] According to a second aspect of the present invention, a method for detecting a transverse shear wavefront based on screen capture is provided, comprising:

[0025] S100, using a shear plate to perform transverse shearing on the wavefront to be measured in two orthogonal directions to generate shear interference fringes;

[0026] S200, projecting the sheared interference fringes onto a scattering screen to form an interference fringe image;

[0027] S300, collecting interference fringe images on the scattering screen;

[0028] S400: Calculating the wavefront information to be measured according to the interference fringe image.

[0029] Specifically, the shear interference fringes include information on the slope of the wavefront to be measured and information on the optical path difference caused by the wedge angle of the shear plate.

[0030] Specifically, the method for calculating the wavefront information to be measured includes:

[0031] The shear interference fringes are unwound to eliminate phase jumps, and the equal-inclination interference component of the optical path difference information is obtained. The equal-inclination interference component caused by the shear plate wedge angle is deducted, and then the processed slope information is converted into a wavefront phase using a wavefront restoration algorithm.

[0032] Beneficial effects:

[0033] The present invention provides a screen-based transverse shear wavefront detection system and method. By using a shear plate, the wavefront to be measured generates shear interference fringes in two orthogonal directions. These fringes are then projected onto a scattering screen. An image acquisition unit then acquires an image of the interference fringes. Finally, a data processing unit obtains the phase information of the wavefront to be measured. This eliminates the need to reduce the wavefront to the size of the camera target surface, reducing the difficulty of collimator measurement and the impact of the aberration of the reducer on measurement accuracy. Compared with existing technologies, this system solves the difficulties of directly measuring the wavefront aberration of the collimator itself and the inability to accurately determine the aberration components and magnitudes. It achieves quantitative measurement of the wavefront aberration of the collimator, improving measurement accuracy and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the composition of a transverse shear wavefront detection system based on screen shooting provided in a specific embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the optical path of a transverse shear wavefront detection system based on screen shooting provided in a specific embodiment of the present invention;

[0036] Figure 3 is a flow chart of a transverse shear wavefront detection method based on screen shooting provided in a specific embodiment of the present invention;

[0037] The reference numerals of the above drawings are as follows:

[0038] 1. First clipping plate; 2. First scattering screen; 3. First lens; 4. First camera; 5. Second clipping plate; 6. Second scattering screen; 7. Second lens; 8. Second camera; 100. Clipping plate; 200. scattering screen; 300. Image acquisition unit; 400. Data processing unit. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is 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 ordinary technicians in this field without making creative work should fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0040] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0041] Example 1

[0042] See also Figure 1 The present embodiment provides a transverse shear wavefront detection system based on screen shooting, comprising 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 the collimator, and solves the problem that the wavefront detection using a traditional wavefront detector requires the wavefront to be contracted to the detector scale, which will introduce the contractor aberration and make it difficult to distinguish between the collimator aberration and the contractor aberration. At the same time, it solves the problem that the fringe observation method using the shear plate 100 and the pentaprism optical axis observation method can only qualitatively determine the type of wavefront aberration but 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 size of the aberration.

[0043] See also Figure 2 Shear plate 100 is used to generate shear interference fringes in two orthogonal directions for the wavefront to be measured. 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 in a first transverse shear direction for the wavefront to be measured, and the second shear plate 5 is used to generate shear interference fringes in a second transverse shear direction for the wavefront to be measured. The second transverse shear direction is orthogonal to the first transverse shear direction. The first shear plate 1 and the second shear plate 5 are wedge-shaped optical plates. The tilt optical path difference information generated by the wedge angle of the wedge-shaped optical plates is pre-calibrated using an interferometer and stored in the data processing unit 400.

[0044] It is understandable that the front and rear surfaces of the shear plate 100 have a wedge angle, and the wavefront will form light with a certain angle through the reflection of the front and rear surfaces, and then interference will occur in the overlapping part, and the interference fringes are periodic fringes of light and dark intersecting.

[0045] For further information, see Figure 2 The diffuser screen 200 is positioned behind the shear plate 100 along the optical path and is used to display the interference fringe image after the shearing by the shear plate 100. The diffuser screen 200 comprises a first diffuser screen 2 and a second diffuser screen 6. The first diffuser screen 2 is positioned behind the first shear plate 1 along the optical path and is located in a plane perpendicular to the first transverse shearing direction. The diffuser screen 2 is used to display the interference fringe image after the shearing by the first shear plate 1. The second diffuser screen 6 is positioned behind the second shear plate 5 along the optical path and is located in a plane perpendicular to the second transverse shearing direction. The diffuser screen 6 is used to display the interference fringe image after the shearing by the second shear plate 5.

[0046] It is understandable that if Figure 2 As shown, in this embodiment, the first transverse shearing direction is the X direction, the second transverse shearing direction is the Y direction, the plane perpendicular to the first transverse shearing direction is the XOZ plane, and the plane perpendicular to the second transverse shearing direction is the XOY plane. That is, the first shear plate 1 causes a certain amount of shearing of the wavefront to be measured in the X direction; the second shear plate 5 causes a certain amount of shearing of the wavefront to be measured in the Y direction; the first scattering screen 2 is placed a certain distance behind the first shear plate 1 and parallel to the XOZ plane, so that interference fringes are imaged thereon; and the second scattering screen 6 is placed a certain distance behind the second shear plate 5 and parallel to the XOY plane, so that interference fringes are imaged thereon, thereby achieving high-precision simultaneous detection of the wavefront in two orthogonal dimensions. The X-direction shearing combined with the XOZ plane scattering screen 200 can obtain transverse phase gradient information of the wavefront, while the Y-direction shearing combined with the XOY plane scattering screen 200 effectively separates longitudinal aberrations, significantly improving the dimensional integrity and measurement resolution of wavefront reconstruction. At the same time, the specific spatial arrangement of the scattering screens 200 optimizes the interference fringe imaging quality, enabling the system to have both multi-degree-of-freedom detection capabilities and environmental interference resistance.

[0047] Preferably, the first scattering screen 2 is placed a certain distance behind the first shear plate 1, and the distance can be set to 10cm-30cm. Similarly, the second scattering screen 6 is placed a certain distance behind the second shear plate 5, and the distance can also be set to 10cm-30cm.

[0048] See also Figure 2In this embodiment, the image acquisition unit 300 is used to acquire the interference fringe image 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 image of the first scattering screen 2. The second image acquisition unit is used to acquire the interference fringe image 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 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. 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.

[0049] See also Figure 1 In this embodiment, the data processing unit 400 is in communication with 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 with sufficient computing power and storage space. It is used to receive the interference fringe image data transmitted by the image acquisition unit 300 and calculate the phase information of the wavefront to be measured using a wavefront reconstruction algorithm.

[0050] Furthermore, the data processing unit 400 analyzes the slopes of the wavefront in two orthogonal directions through the interference fringe image information recorded by the first camera 4 and the second camera 8 and then integrates them to obtain the phase information of the wavefront to be measured.

[0051] It can be understood that the shearing interference fringes contain both information about the slope of the wavefront to be measured and information about the optical path difference caused by the angle between the front and rear surfaces of the shear plate 100, namely the wedge angle. After the shear plate 100 is machined, an interferometer is used to detect the surface shape difference between the front and rear surfaces of the shear plate 100. This surface shape difference primarily represents the tilt caused by the wedge angle of the shear plate 100. After the data processing unit 400 unwraps the interference fringes, the tilt component caused by the shear plate 100, as measured by the interferometer, is deducted to obtain the slope of the wavefront to be measured. A wavefront restoration algorithm then converts the wavefront slope information in two orthogonal directions into the wavefront information to be measured. Based on the above scheme, the present invention utilizes a scattering screen 200 to receive the interference fringe image and a camera and lens to capture the interference fringes on the scattering screen 200. This allows for complete recording of the wavefront information to be measured without the need for beam reduction, further improving the accuracy of wavefront measurement.

[0052] See also Figure 2In this embodiment, the operating principle of the screen-shooting-based transverse shear wavefront detection system is as follows: the wavefront to be measured first passes through the first shear plate 1, generating shear interference fringes in the first transverse shear direction. These interference fringes are projected onto the first scattering screen 2 to form a visible interference fringe image. The first image acquisition unit captures 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, generating shear interference fringes in the second transverse shear direction. These interference fringes are projected onto the second scattering screen 6 to form a visible interference image. The second image acquisition unit captures the interference fringe image on the second scattering screen 6 and transmits the image data to the data processing unit 400.

[0053] Furthermore, after receiving the interference fringe images from both directions, the data processing unit 400 first unwraps the interference fringes to eliminate phase jumps, obtaining the equal-inclination interference component of the optical path difference information. The data processing unit 400 then deducts 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). Finally, the data processing unit 400 uses a wavefront restoration algorithm to convert the processed slope information into a wavefront phase, thereby obtaining the complete wavefront information to be measured.

[0054] It should be noted here that the transverse shear wavefront detection system based on screen shooting in this embodiment has the characteristics of simple structure, easy operation and high measurement accuracy. By performing wavefront shearing in two orthogonal directions at the same time, the complete slope information of the wavefront in two directions can be obtained, thereby realizing comprehensive detection of the wavefront. The use of the scattering screen allows 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. There is no need to shrink the wavefront to be measured to the size of the camera target surface, which reduces the difficulty of measuring the collimator and also reduces the influence of the aberration of the beam reducer on the measurement accuracy. Compared with the existing technology, it solves the problem of difficulty in directly measuring the wavefront aberration of the collimator itself and the inability to accurately give the aberration component and size, realizes the quantitative measurement of the wavefront aberration of the collimator, and improves the accuracy and efficiency of the measurement.

[0055] Example 2

[0056] See also Figure 3 This embodiment provides a method for detecting lateral shear wavefronts based on screen capture, which specifically includes the following steps:

[0057] S100, using the shear plate 100 to perform transverse shearing on the wavefront to be measured in two orthogonal directions to generate shear interference fringes;

[0058] S200, projecting the sheared interference fringes onto the scattering screen 200 to form an interference fringe image;

[0059] S300, collecting interference fringe images on the scattering screen 200;

[0060] S400: Calculate the wavefront information to be measured according to the interference fringe image.

[0061] It is understood that the present invention records shearing interference information in two orthogonal directions by means of screen capture. This method does not require wavefront constriction, reducing the impact of constrictor aberrations on wavefront detection. It not only identifies the type of aberration but also quantitatively analyzes the magnitude of the aberration, greatly improving the usability and reliability of the present invention.

[0062] Furthermore, in step S100, the shearing interference fringes include information about the slope of the wavefront to be measured and information about the optical path difference caused by the wedge angle of shear plate 100. Specifically, first shear plate 1 is used to shear the wavefront to be measured in a first transverse shear direction, generating shearing interference fringes in the first transverse shear direction. Simultaneously, second shear plate 5 is used to shear the wavefront to be measured in a second transverse shear direction, generating shearing interference fringes in the second transverse shear direction. The first and second transverse shear directions are perpendicular to each other, forming an orthogonal relationship. This allows complete slope information of the wavefront in both orthogonal directions to be obtained.

[0063] Furthermore, in step S200, the sheared interference fringes in the first direction are projected onto the first scattering screen 2 to form a first interference fringe image; and the sheared 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 on a plane perpendicular to the first transverse shearing direction, and the second scattering screen 6 is located on a plane perpendicular to the second transverse shearing direction. The scattering screen 200 can be made of a material with scattering properties, capable of clearly displaying the interference fringes projected onto it.

[0064] Furthermore, in step S300, a first image acquisition unit is used to capture an interference fringe image on the first scattering screen 2; and a second image acquisition unit is used to capture an 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 region 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 region of the second scattering screen 6. The image acquisition unit 300 transmits the captured interference fringe image data to the data processing unit 400.

[0065] Furthermore, in step S400, the method for calculating the wavefront information to be measured includes: unwrapping the shear 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 shear plate 100, and then using a wavefront restoration algorithm to convert the processed slope information into a wavefront phase. The specific steps are as follows:

[0066] Step 1: The data processing unit 400 first pre-processes the collected interference fringe image, including image filtering, enhancement and other operations to improve image quality;

[0067] Step 2: Perform phase unwrapping on the processed interference fringe image to eliminate phase jumps and obtain a continuous phase distribution;

[0068] Step 3: Extract the iso-inclined interference component from the phase distribution and deduct the iso-inclined interference component caused by the wedge angle of the shear plate 100 (this information has been pre-calibrated using the interferometer and stored in the data processing unit);

[0069] Step 4: Use a wavefront restoration algorithm, such as the integral method, pattern method, or regional method, to convert the processed slope information into a wavefront phase, thereby obtaining complete wavefront information to be measured.

[0070] It should be further explained that the shear plate uses reflections from its front and back surfaces to copy the wavefront to be measured into two. The angle of the shear plate causes the copied wavefront and the original wavefront to be transmitted at a certain angle. 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 information of the interference fringes on the scattering screen. Because the interference fringes in a single shearing direction simultaneously carry 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 shearing direction, by subjecting the wavefront to be measured to shear interference in two orthogonal directions, unwrapping the interference fringes using the data processing unit 400, and then removing the equal-inclination interference component caused by the shear plate wedge angle (this component can be obtained by measuring the surface shape of the front and back surfaces of the shear plate using an interferometer), the wavefront gradients of the wavefront to be measured in the two orthogonal directions can be obtained. The process of converting wavefront gradient information to wavefront phase information is called wavefront restoration, and the measured wavefront gradient information can be restored using wavefront restoration algorithms such as the integral method, the pattern method, or the regional method.

[0071] It should be noted here that the transverse shear wavefront detection method based on screen shooting in this embodiment has the characteristics of simple operation and high measurement accuracy. By performing wavefront shearing in two orthogonal directions at the same time, the complete slope information of the wavefront in two directions can be obtained, thereby realizing comprehensive detection of the wavefront. The use of a scattering screen allows 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, and the data processing unit can extract accurate wavefront phase information therefrom through a special algorithm. There is no need to shrink the wavefront to be measured to the size of the camera target surface, which reduces the difficulty of measuring the collimator and also reduces the influence of the aberration of the beam reducer on the measurement accuracy. Compared with the prior art, it solves the problem of difficulty in directly measuring the wavefront aberration of the collimator itself and the inability to accurately give the aberration component and size, realizes the quantitative measurement of the wavefront aberration of the collimator, and improves the accuracy and efficiency of the measurement.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0073] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0074] The various 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 combination does not conflict.

[0075] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A transverse shear wavefront detection system based on screen shooting, characterized in that: include: A shear plate (100) is used to generate shear interference fringes in two orthogonal directions on the wavefront to be measured; A scattering screen (200) is arranged behind the shear plate (100) along the propagation direction of the light path and is used to display the interference fringe image after shearing by the shear plate (100); An image acquisition unit (300) for acquiring an interference fringe image of the scattering screen (200); A data processing unit (400) is connected in communication with the image acquisition unit (300) and is used to calculate the wavefront information to be measured; The shear plate (100) comprises a first shear plate (1) and a second shear plate (5); The first shear plate (1) is used to cause the wavefront to be measured to generate shear interference fringes in a first transverse shear direction, and the second shear plate (5) is used to cause the wavefront to be measured to generate shear interference fringes in a second transverse shear direction; The second transverse shear direction is orthogonal to the first transverse shear direction; The scattering screen (200) comprises 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 propagation direction of the light path and is located in a plane perpendicular to the first transverse shearing direction, and is used to display the interference fringe image after shearing by the first shear plate (1); The second scattering screen (6) is arranged behind the second shear plate (5) along the propagation direction of the light path and is located in a plane perpendicular to the second transverse shearing direction, and is used to display the interference fringe image after shearing by the second shear plate (5); The first shear plate (1) and the second shear plate (5) are wedge-shaped optical flat plates, and an interferometer is used to pre-calibrate the tilt optical path difference information generated by the wedge angle of the wedge-shaped optical flat plates and store it in a data processing unit (400).

2. The screen-shooting-based transverse shear wavefront detection system according to claim 1, characterized in that: The image acquisition unit (300) comprises a first image acquisition unit and a second image acquisition unit; The first image acquisition unit (300) is used to acquire the interference fringe image of the first scattering screen (2); The second image acquisition unit is used to acquire the interference fringe image of the second scattering screen (6).

3. The screen-shooting-based lateral shear wavefront detection system according to claim 2, characterized in that: The first image acquisition unit comprises a first camera (4) and a first lens (3), the first lens (3) being mounted on the first camera (4), the imaging optical axis of the first lens (3) being perpendicular to the surface of the first scattering screen (2), and the target surface of the first camera (4) covering the interference fringe area of ​​the first scattering screen (2).

4. The screen-shooting-based transverse shear wavefront detection system according to claim 3, characterized in that: The second image acquisition unit comprises a second camera (8) and a second lens (7), the second lens (7) being mounted on the second camera (8), the imaging optical axis of the second lens (7) being perpendicular to the surface of the second scattering screen (6), and the target surface of the second camera (8) covering the interference fringe area of ​​the second scattering screen (6).

5. A method for detecting transverse shear wavefront based on screen shooting, characterized in that: Using the screen-shooting-based lateral shear wavefront detection system according to any one of claims 1 to 4, the method comprises: S100, using a shear plate (100) to perform transverse shearing on the wavefront to be measured in two orthogonal directions to generate shear interference fringes; S200, projecting the sheared interference fringes onto a scattering screen (200) to form an interference fringes image; S300, collecting an interference fringe image on the scattering screen (200); S400: Calculating the wavefront information to be measured according to the interference fringe image.

6. The method for detecting transverse shear wavefronts based on screen capture according to claim 5, characterized in that: The shear interference fringes include information on the slope of the wavefront to be measured and information on the optical path difference caused by the wedge angle of the shear plate (100).

7. The method for detecting transverse shear wavefronts based on screen capture according to claim 6, wherein: The method for calculating the wavefront information to be measured comprises: The shear interference fringes are unwound to eliminate phase jumps, and the equal-inclination interference component of the optical path difference information is obtained. The equal-inclination interference component caused by the wedge angle of the shear plate (100) is deducted, and the processed slope information is converted into a wavefront phase using a wavefront restoration algorithm.

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