Computer-generated holographic element, clamping device, detection system and aspheric element detection method

Abstract

The embodiment of the invention provides a computer-generated hologram element, a clamping device, a detection system and an aspheric element detection method. The computer-generated hologram element comprises a first holographic area, a second holographic area and a third holographic area, the first holographic area, the second holographic area and the third holographic area are formed on at least one of the first side and the second side of the computer-generated hologram element, and the first side and the second side are the two opposite sides of the computer-generated hologram element in the thickness direction; the first holographic region is constructed as a reflective grating and can reflect a first spherical wave incident to the first holographic region from the first side along an original optical path; the second holographic region is constructed as a transmission-type grating, and can transmit a first spherical wave which is incident to the second holographic region from the first side from the second side and convert the first spherical wave into a plane wave; the third holographic area is constructed to be a transmission-type grating which can transmit a first spherical wave incident to the third holographic area from the first side from the second side and convert the first spherical wave into a second spherical wave with a convergence focus.

Description

Technical Field

[0001] This disclosure relates to the field of optical technology, and in particular to a computational holographic element, a clamping device, a detection system, and a method for detecting aspherical elements. Background Technology

[0002] Currently, computational holography (CGH) elements are frequently used for the inspection of aspherical components. Using CGH elements for aspherical inspection offers advantages such as high accuracy, small design residuals, and non-contact measurement, thus avoiding scratches on the aspherical component under test and allowing for the measurement of the entire surface. However, the inspection of aspherical components using CGH elements requires high precision in the assembly and adjustment of the entire inspection system; large assembly and adjustment errors will lead to significant measurement errors. Therefore, it is necessary to effectively improve the equipment assembly and inspection accuracy of aspherical component inspection systems. Summary of the Invention

[0003] In a first aspect of this disclosure, a computational holographic element is provided, comprising: a first holographic region, a second holographic region, and a third holographic region, wherein the first holographic region, the second holographic region, and the third holographic region are all formed on at least one of a first side and a second side of the computational holographic element, the first side and the second side being two opposite sides of the computational holographic element along the thickness direction; the first holographic region is configured as a reflective grating, capable of reflecting a first spherical wave incident from the first side to the first holographic region along the original optical path; the second holographic region is configured as a transmissive grating, capable of transmitting the first spherical wave incident from the first side to the second holographic region from the second side and converting it into a plane wave; the third holographic region is configured as a transmissive grating, capable of transmitting the first spherical wave incident from the first side to the third holographic region from the second side and converting it into a second spherical wave having a focal point.

[0004] A second aspect of this disclosure provides a clamping device, comprising: a clamping mechanism and a specular reflection mechanism; the clamping mechanism is configured to clamp an aspherical element to be tested, and includes a bearing surface capable of supporting the aspherical element to be tested when clamping it; the specular reflection mechanism is disposed on the clamping mechanism, and is used to specularly reflect a plane wave transmitted and converted by a second holographic region of a computational holographic element provided according to the first aspect; wherein the specular reflection mechanism satisfies any of the following conditions: the reflecting surface of the specular reflection mechanism is parallel to the bearing surface; the reflecting surface of the specular reflection mechanism is coplanar with the bearing surface.

[0005] A third aspect of this disclosure provides a detection system for detecting an aspherical element under test. The detection system includes: an interferometer, a computational holographic element as provided in the first aspect, and a clamping device as provided in the second aspect, arranged sequentially. The clamping device is used to clamp the aspherical element under test. The interferometer is used to emit a first spherical wave to the computational holographic element, and the interferometer is further used to: receive a first interference light generated by a first return light reflected from a first holographic region and a reference light of the interferometer, forming a first interference fringe; receive a second interference light generated by a second return light transmitted from a second holographic region, reflected by a mirror reflection mechanism, and then transmitted again from the second holographic region, and a reference line of the interferometer, forming a second interference fringe; and receive a third interference light generated by a third return light transmitted from a third holographic region, reflected by the aspherical element under test, and then transmitted again from the third holographic region, and a reference light of the interferometer, forming a third interference fringe.

[0006] A fourth aspect of this disclosure provides a method for detecting aspherical elements, employing the detection system provided in the third aspect. The detection method includes: adjusting at least one of the position and orientation of a computational holographic element relative to an interferometer until a first interference fringe satisfies a first condition, thereby adjusting the computational holographic element to a preset position; adjusting the orientation of a clamping device until a second interference fringe satisfies a second condition, thereby aligning the optical axis of the aspherical element under test located on the clamping device with the optical axis of the interferometer; and adjusting the position of the clamping device until a third interference fringe satisfies a third condition, thereby determining the vertex position of the aspherical element under test. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings.

[0008] Figure 1 This is a schematic diagram of some exemplary detection systems in the embodiments of this disclosure.

[0009] Figure 2 This is a schematic diagram of some exemplary computational holographic elements in the embodiments of this disclosure.

[0010] Figure 3 This is a schematic diagram of some exemplary clamping devices in the embodiments of this disclosure.

[0011] Figure 4 This is a flowchart of some exemplary aspherical element detection methods in the embodiments of this disclosure.

[0012] Figure 5This is a schematic diagram showing the measurement of the vertex position of the aspherical element under test in both tilted and non-tilted states.

[0013] Figure 6 This is an optional flowchart of step S406 in an embodiment of this disclosure.

[0014] Figure 7 This is an optional flowchart of step S4061 in an embodiment of this disclosure.

[0015] Figure 8 This is a schematic diagram of the path for scanning vertex positions in a plane orthogonal to the axis of the interferometer in an embodiment of this disclosure.

[0016] Explanation of reference numerals in the attached figures:

[0017] 10. Aspherical element under test; 100. Computational holographic element; 110. First holographic region; 120. Second holographic region; 130. Third holographic region; 140. Fourth holographic region; 200. Clamping device; 210. Clamping mechanism; 220. Mirror reflection mechanism; 300. Interferometer; 310. Standard spherical mirror; 400. Detection system. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in the embodiments of this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure should fall within the protection scope of this disclosure. It should be understood that the various steps described in the method implementation of this disclosure can be performed in different orders and / or in parallel. Furthermore, the method implementation may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0019] Currently, computational holography (CGH) elements are frequently used for the inspection of aspherical components. Using CGH elements for aspherical inspection offers advantages such as high accuracy and small design residuals. Furthermore, it is a non-contact measurement method, thus avoiding scratches on the aspherical component under test and allowing for the measurement of the entire surface. However, the inspection of aspherical components using CGH elements requires high precision in the assembly and adjustment of the entire inspection system. Excessive assembly and adjustment errors will lead to significant measurement errors. This is especially true when the aspherical component has poor central surface symmetry, making it difficult to adjust the tilt and eccentricity of the component, which can easily amplify assembly and adjustment errors and further impact measurement accuracy. Therefore, it is necessary to effectively improve the equipment assembly and inspection accuracy of aspherical component inspection systems.

[0020] The technical solutions of the embodiments of this disclosure will be described below with reference to the accompanying drawings. It should be noted that, for the purpose of explaining the embodiments of this disclosure, the various drawings of the embodiments of this disclosure are not necessarily drawn to scale. They are only used to facilitate the explanation of the technical solutions and are not intended to limit the embodiments of this disclosure in any way.

[0021] Some embodiments of this disclosure provide a detection system for detecting the optical surface of an optical element. The detection system 400 includes, sequentially arranged, an interferometer 300, a computational holographic element 100, and a clamping device 200. The clamping device 200 is used to clamp the optical element under test. The interferometer 300 emits a first measurement light and a reference light. The first measurement light emitted by the interferometer 300 is transformed by the computational holographic element 100 into a second measurement light with a predetermined wavefront, wherein at least a portion of the second measurement light is incident on the surface of the aspherical element 10 under test. A portion of the second measurement light, after being transmitted or reflected by the surface of the aspherical element 10 under test, interferes with the reference light emitted by the interferometer 300, forming interference light. The interferometer 300 receives the interference light and forms interference fringes. The interference fringes can reflect the surface profile of the optical surface of the optical element under test.

[0022] Figure 1 Schematic diagrams of some exemplary detection systems according to embodiments of this disclosure are shown. For example... Figure 1As shown, the detection system 400 is used to detect aspherical elements. The detection system 400 includes: an interferometer 300, a computational holographic element 100, and a clamping device 200 arranged sequentially. The clamping device 200 is used to clamp the aspherical element 10 to be tested. The interferometer 300 emits a first measurement light and a reference light to the computational holographic element 100. The first measurement light is transformed into a second measurement light with a set wavefront after passing through the computational holographic element 100, wherein at least a portion of the second measurement light is incident on the surface of the aspherical element 10 to be tested. A portion of the second measurement light, after being transmitted or reflected from the surface of the aspherical element 10 to be tested, interferes with the reference light emitted by the interferometer 300, forming interference fringes.

[0023] Figure 2 Schematic diagrams of some exemplary computational holographic elements in embodiments of this disclosure are shown. (Refer to...) Figure 2 As shown, the computational holographic element 100 provided in some embodiments of this disclosure includes: a first holographic region 110, a second holographic region 120 and a third holographic region 130, and the first holographic region 110, the second holographic region 120 and the third holographic region 130 are all formed on at least one of the first side and the second side of the computational holographic element 100, and the first side and the second side are two opposite sides of the computational holographic element 100 along the thickness direction.

[0024] For example, as Figure 1 Taking the detection system 400 shown as an example, an example of a first side and a second side of the computational holographic element 100 is shown. The first side and the second side of the computational holographic element 100 are two opposite sides of the computational holographic element 100 along the thickness direction. In one usage, when performing aspherical element detection using the computational holographic element 100, the first side of the computational holographic element 100 can be oriented towards the interferometer 300 of the detection system 400, so that the interferometer 300 can emit a first measurement light towards the first side of the computational holographic element 100, which is transformed after reflection and / or transmission by the computational holographic element 100. This can be used in the equipment setup and detection process for aspherical element detection.

[0025] Optionally, refer to Figure 1 As shown, the interferometer 300 of the detection system 400 may include a standard spherical mirror 310. The interferometer 300 uses the standard spherical mirror 310 to make the first measurement light emitted outward a first spherical wave.

[0026] In some embodiments of this disclosure, the first holographic region 110 may be configured as a reflective grating capable of reflecting a first spherical wave incident from the first side onto the first holographic region 110 along the original optical path.

[0027] Optionally, the first holographic region 110 can also be called the alignment holographic region, which can be used to assist in adjusting the position and tilt of the computational holographic element 100 relative to the standard spherical mirror 310 of the interferometer 300, and align the optical axis of the computational holographic element 100 with the optical axis of the standard spherical mirror 310.

[0028] Alternatively, the first holographic region 110 can be configured as an amplitude-type reflective grating.

[0029] Optionally, during the equipment setup and adjustment stage for aspherical element detection, the interferometer 300 emits a first spherical wave to the first side of the computational holographic element 100 via a standard spherical mirror 310. The first spherical wave is incident on the first holographic region 110 from the first side. The first holographic region 110, with its reflective grating structure, reflects the incident first spherical wave, causing the reflected first return light to return to the interferometer 300 along the original optical path. The first return light interferes with the reference light inside the interferometer 300, generating first interference light to form first interference fringes. Based on the state of the first interference fringes, the detection system 400 can be set up and adjusted to conveniently adjust the position and tilt of the computational holographic element 100 relative to the standard spherical mirror 310 of the interferometer 300, ensuring that the optical axis of the computational holographic element 100 is aligned with the optical axis of the interferometer 300, thus facilitating accurate aspherical element detection.

[0030] It should be understood that the specific structure and location of the first holographic region 110 are not limited in this embodiment. For example, refer to... Figure 2 In the example of the computational holographic element 100, the first holographic region 110 can be annular. The annular first holographic region 110 can receive and reflect the first spherical wave more uniformly, so as to improve the equipment adjustment effect and detection effect when detecting aspherical elements.

[0031] In some embodiments of this disclosure, the second holographic region 120 may be configured as a transmissive grating capable of transmitting a first spherical wave incident from the first side to the second holographic region 120 from the second side and converting it into a plane wave.

[0032] Optionally, the second holographic region 120 can also be called the plane wave holographic region, which can be used to assist in adjusting the tilt of the aspherical element under test relative to the interferometer 300, aligning the optical axis of the aspherical element under test 10 with the optical axis of the interferometer 300 and the optical axis of the holographic element 100.

[0033] Optionally, during the equipment setup and adjustment stage for testing aspherical elements, the interferometer 300 emits a first spherical wave to the first side of the computational holographic element 100 via a standard spherical mirror 310. The first spherical wave is incident from the first side onto the second holographic region 120. The second holographic region 120, with its transmissive grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100, converting it into a plane wave. The plane wave can be reflected to the second holographic region 120 via a mirror reflection mechanism 220 on the clamping device 200 (described in detail below), and then transmitted through the second holographic region 120 to form a second return light. The second return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300, generating a second interference light to form a second interference fringe. Based on the state of the second interference fringes, the tilt state of the aspherical element 10 under test relative to the interferometer 300 can be adjusted so that the optical axis of the aspherical element 10 under test can be aligned with the optical axis of the interferometer 300 and the optical axis of the computational holographic element 100, so as to facilitate accurate detection of the aspherical element.

[0034] Using the computational holographic element 100 of this embodiment, when adjusting the tilt of the aspherical element 10 under test relative to the interferometer 300, the second holographic region 120 and the mirror reflection mechanism 220 of the clamping device 200 can cooperate to form a second interference fringe by interfering with the reference light inside the interferometer 300 through the second returned light generated by the first plane wave. Adjustment is then made based on the second interference fringe. Therefore, the assembly and adjustment speed and accuracy of the aspherical element can be effectively improved. This embodiment is also applicable to the tilt and eccentricity adjustment of aspherical elements with asymmetrical central surfaces, thereby facilitating the reduction of assembly and adjustment errors and improving the detection accuracy of aspherical elements.

[0035] It should be understood that the specific structure and location of the second holographic region 120 are not limited in this embodiment. For example, refer to... Figure 2 In the example of the computational holographic element 100, the second holographic region 120 can be a rounded rectangle. Alternatively, it can be a regular shape such as a rectangle or a circle, or it can be other irregular shapes.

[0036] Optionally, refer to Figure 2 As shown, the second holographic region 120 may be located on at least one of the first holographic region 110 and the third holographic region 130. In this way, the volume of the computational holographic element 100 can be reduced without affecting the function of the first holographic region 110 and the third holographic region 130.

[0037] Optionally, the second holographic region 120 of the holographic element 100 can be a single entity. Alternatively, refer to... Figure 2As shown, the second holographic region 120 of the holographic element 100 may include multiple regions, and the multiple second holographic regions 120 may be spaced apart on at least one of the first holographic region 110 and the third holographic region 130. Figure 2 As shown, in this example, the computational holographic element 100 includes two second holographic regions 120. Optionally, a plurality of second holographic regions 120 may be uniformly disposed on at least one of the first holographic region 110 and the third holographic region 130. Optionally, referring to... Figure 2 As shown, multiple second holographic regions 120 can be evenly disposed on the first holographic region 110 and the third holographic region 130. Optionally, referring to... Figure 2 As shown, the second holographic region 120 is distributed at intervals around the optical axis of the computational holographic element 100. Optionally, refer to... Figure 2 As shown, the multiple second holographic regions 120 have the same shape and are evenly distributed at equal intervals around the optical axis of the computational holographic element 100. It should be understood that the multiple second holographic regions 120 can also have different shapes, as long as they meet the usage requirements. In this embodiment, using multiple second holographic regions 120 can better improve the equipment assembly accuracy of the detection system 400, facilitating more accurate detection of aspherical elements.

[0038] In some embodiments of this disclosure, the third holographic region 130 may be configured as a transmissive grating capable of transmitting a first spherical wave incident from the first side to the third holographic region 130 from the second side and converting it into a second spherical wave with a focal point.

[0039] Optionally, the third holographic region 130 can also be called the cat's eye holographic region, which can be used to test the vertex position of the aspherical element and assist in adjusting the vertex position of the aspherical element to calculate the axial distance of the holographic element 100.

[0040] Optionally, during the equipment setup and adjustment stage for aspherical element testing, the interferometer 300 emits a first spherical wave towards the first side of the computational holographic element 100 via a standard spherical mirror 310. The first spherical wave is incident from the first side onto the third holographic region 130. The third holographic region 130, with its transmission grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100, converting it into a second spherical wave with a focal point. The second spherical wave can be reflected by the aspherical element under test to the third holographic region 130, and then transmitted through the third holographic region 130, forming a third return light. The third return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300, generating a third interference light to form a third interference fringe. The axial distance between the aspherical element under test and the computational holographic element 100 can be adjusted according to the state of the third interference fringe to facilitate the detection of the apex of the aspherical element under test.

[0041] It should be understood that the specific structure and location of the third holographic region 130 are not limited in the embodiments disclosed herein. For example, refer to... Figure 2 In the example of the computational holographic element 100, the third holographic region 130 can be annular. The annular third holographic region 130 can be more conducive to receiving and transmitting the first spherical wave, so as to improve the equipment adjustment effect and detection effect when detecting aspherical elements.

[0042] Based on this, in this embodiment of the present disclosure, the optional computational holographic element 100, when applied to a detection system for aspherical elements under test, can assist in the equipment assembly and adjustment of the detection system through its first holographic region 110, second holographic region 120, and third holographic region 130, thereby improving the accuracy of equipment assembly and adjustment, and thus facilitating the subsequent improvement of the detection accuracy of the aspherical elements under test. Furthermore, it can be effectively applied to the detection of various aspherical elements, whether symmetrical or asymmetrical, and can achieve high accuracy in all cases.

[0043] In some alternative embodiments, the computational holographic element 100 further includes a fourth holographic region 140, which is formed on at least one of the first side and the second side; the fourth holographic region 140 may be configured as a transmissive grating and is capable of transmitting a first spherical wave incident from the first side to the fourth holographic region 140 from the second side and converting it into a preset standard aspherical wave.

[0044] Optionally, the fourth holographic region 140 can also be referred to as the main holographic region. During the detection of aspherical elements, it can be used to generate a preset standard aspherical wave for zero-position interference of the aspherical element 10 under test, so as to facilitate interference detection of the aspherical element 10 under test. For example, zero-position interference detection can be performed on the aspherical element under test.

[0045] Optionally, during aspherical element detection, the interferometer 300 emits a first spherical wave to the first side of the computational holographic element 100 via a standard spherical mirror 310. This first spherical wave is transmitted from the first side to the fourth holographic region 140. The fourth holographic region 140, with its transmissive grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100 and converts it into a preset standard aspherical wave. This preset standard aspherical wave can be reflected by the aspherical element under test. The light reflected back to the fourth holographic region 140 is then transmitted through the fourth holographic region 140, forming a fourth return light. This fourth return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300, generating a fourth interference light to form a fourth interference fringe. Interference detection (e.g., zero-position interference detection) can be performed on the aspherical element 10 under test based on the state of the fourth interference fringe.

[0046] Based on this, in this embodiment, the computational holographic element 100 can effectively perform interference detection on the aspherical element 10 under test through the aforementioned fourth holographic region 140. Furthermore, taking the detection system 400 as an example, the detection accuracy of the fourth holographic region 140 is related not only to the generation accuracy of its own aspherical wave, but also to the relative positions of the computational holographic element 100 and the standard spherical mirror 310 of the interferometer 300, and the relative positions of the computational holographic element 100 and the aspherical element 10 under test. Since the first holographic region 110 and the second holographic region 120 in this embodiment can effectively improve the assembly accuracy of the above two relative positions, given a certain generation accuracy of the aspherical wave in the fourth holographic region 140, the computational holographic element 100 in this embodiment can effectively improve the detection accuracy of the fourth holographic region 140, thereby enabling more precise interference detection of the aspherical element 10 under test.

[0047] It should be understood that the specific structure and location of the fourth holographic region 140 are not limited in this embodiment. For example, refer to... Figure 2 In the example of the computational holographic element 100, the fourth holographic region 140 can be circular, or it can be a regular shape such as a square, or it can be other irregular shapes.

[0048] In some alternative embodiments, refer to Figure 2 For example, the first holographic region 110 and the third holographic region 130 are both annular and surround the outside of the fourth holographic region 140, and the second holographic region 120 is located on at least one of the first holographic region 110 and the third holographic region 130.

[0049] Optionally, the first holographic region 110 and the third holographic region 130 can be, in addition to being, Figure 2 The circular shape shown and mentioned above can also be other shapes of rings, such as rectangular rings, oblong rings, etc.

[0050] Optionally, refer to Figure 2 For example, the fourth holographic region 140 is circular, the first holographic region 110 can be disposed around the outside of the fourth holographic region 140, and the third holographic region 130 can be disposed around the outside of the first holographic region 110.

[0051] In some alternative embodiments, the fourth holographic region 140 is circular, the third holographic region 130 may be disposed around the outside of the fourth holographic region 140, and the first holographic region 110 may be disposed around the outside of the third holographic region 130.

[0052] It should be understood that the annular widths of the first holographic region 110 and the third holographic region 130 are not specifically limited in this embodiment. When necessary, the annular width of the third holographic region 130 can be set slightly larger to improve the detection accuracy of the aspherical element under test through the third holographic region 130. This is because the detection accuracy of the third holographic region 130 in the axial direction (i.e., the optical axis direction) can be understood as shown in the following formula:

[0053]

[0054] Where z represents the axial position error, Δw is the wavefront PV (Peak-Valley) value of the third interference light forming the third interference fringe, and F is the F-number of the preset standard aspherical wave beam transmitted through the third holographic region 130. With Δw constant, increasing the annular width of the third holographic region 130 reduces F, thus decreasing the axial position error z of the third holographic region 130. A smaller position error results in higher axial position detection accuracy. Therefore, the annular width of the third holographic region 130 can be set as large as possible to improve the detection accuracy of the aspherical element under test through the third holographic region 130.

[0055] Based on this, in this embodiment of the present disclosure, by setting the first holographic region 110 and the third holographic region 130 in a ring around the outside of the fourth holographic region 140, and setting the second holographic region 120 on at least one of the first holographic region 110 and the third holographic region 130, on the one hand, the structure of the computational holographic element 100 is made more compact without affecting the function of the computational holographic element 100; on the other hand, it is more conducive to receiving and transmitting the first spherical wave, so as to improve the equipment adjustment effect and detection effect when detecting aspherical elements; furthermore, other holographic regions do not interfere with the fourth holographic region 140 used for interference detection, so as to achieve more accurate interference detection of the aspherical element 10 under test.

[0056] The clamping device 200 will be described below. Figure 3 A schematic diagram of some exemplary clamping devices according to embodiments of this disclosure is shown. (Refer to...) Figure 3As shown, some embodiments of the present disclosure provide a computational holographic element 100 including a clamping mechanism 210 and a specular reflection mechanism 220. The clamping mechanism 210 may be configured to clamp the aspherical element 10 to be measured, and includes a bearing surface capable of supporting the aspherical element 10 to be measured when clamping it. Optionally, the specular reflection mechanism 220 may be disposed around the clamping mechanism 210 or on the bearing surface of the clamping mechanism 210. The specular reflection mechanism 220 is used to specularly reflect the plane wave transmitted and converted by the second holographic region 120 of the computational holographic element 100 as provided in any of the above embodiments; wherein the specular reflection mechanism 220 satisfies any of the following conditions: the reflecting surface of the specular reflection mechanism 220 is parallel to the bearing surface; the reflecting surface of the specular reflection mechanism 220 is coplanar with the bearing surface.

[0057] Based on this, the aforementioned clamping device 200 can support the aspherical element 10 to be tested via the bearing surface of the clamping mechanism 210, and reflect the plane wave transmitted and converted by the second holographic region 120 of the computational holographic element 100 via the reflecting surface of the mirror reflection mechanism 220, which is parallel or coplanar with the bearing surface. This facilitates precise and convenient equipment assembly and adjustment using the second holographic region 120. Therefore, by using the clamping device 200 in conjunction with the computational holographic element 100, the equipment assembly and adjustment of the detection system can be effectively assisted, improving the accuracy of equipment assembly and adjustment, thereby improving the detection accuracy of the aspherical element under test in subsequent processes.

[0058] Using the clamping device 200 of this embodiment, when adjusting the tilt of the aspherical element 10 under test relative to the interferometer 300, the second holographic region 120 of the holographic element 100 and the mirror reflection mechanism 220 of the clamping device 200 can be used in conjunction to form a second interference fringe by interfering with the reference light inside the interferometer 300 through the second reflected light generated by the first plane wave. Adjustment is then made based on the second interference fringe. Furthermore, this solution is effectively applicable to adjusting the tilt and eccentricity of aspherical elements with asymmetrical central surfaces, facilitating the reduction of equipment assembly and adjustment errors, reducing measurement errors, and improving detection accuracy.

[0059] In some embodiments of this disclosure, the clamping mechanism 210 has a bearing surface. When clamping the aspherical element 10 to be tested, the aspherical element 10 is pressed against the bearing surface of the clamping mechanism 210. At this time, it is assumed that the optical axis of the aspherical element to be tested is perpendicular to the bearing surface. Subsequently, when adjusting the position of the clamping device 200, it is necessary to ensure that the relative position of the aspherical element 10 to be tested and the bearing surface remains unchanged. In this way, when adjusting the tilt state of the aspherical element to be tested according to the second interference fringe, after the reflecting surface of the mirror reflection mechanism 220 is perpendicular to the optical axis of the computational holographic element 100, the optical axis of the aspherical element 10 to be tested is aligned with the optical axis of the interferometer 300 and the optical axis of the computational holographic element 100.

[0060] Combination Figure 1 Taking the detection system 400 as an example, the mirror reflection mechanism 220 can mirror-reflect the plane wave transmitted and converted by the second holographic region 120 of the computational holographic element 100. The plane wave is mirror-reflected by the mirror reflection mechanism 220 and then transmitted through the second holographic region 120 to form a second return light that returns to the interferometer 300. The second return light interferes with the reference light inside the interferometer 300 to generate a second interference light, thus forming a second interference fringe. By adjusting the posture of the clamping device 200 according to the second interference fringe, the tilt state of the aspherical element 10 under test relative to the interferometer 300 can be conveniently and effectively adjusted, so that the optical axis of the aspherical element 10 under test can be aligned with the optical axis of the interferometer 300 and the optical axis of the computational holographic element 100, so as to facilitate accurate detection of the aspherical element.

[0061] In some alternative embodiments, the position of the mirror reflection mechanism 220 on the clamping device 200 corresponds to the position of the second holographic region 120 on the computational holographic element 100.

[0062] It should be understood that one interpretation of the position mentioned in the embodiments of this disclosure is: the projection of the second holographic region 120 toward the clamping device 200 is at least partially located in the area where the mirror reflection mechanism 220 is located on the clamping device 200.

[0063] Based on this, in the above optional embodiment, the clamping device 200, by aligning the position of the mirror reflection mechanism 220 on the clamping device 200 with the position of the second holographic region 120 on the computational holographic element 100, can ensure that the plane wave reflected by the mirror reflection mechanism 220 is reflected back to the second holographic region 120 as much as possible. Thus, the clamping device 200, in conjunction with the computational holographic element 100, facilitates the adjustment of the tilt state of the optical axis of the aspherical element under test, improving the equipment assembly accuracy and subsequently enhancing the detection accuracy of the aspherical element under test.

[0064] Optionally, the projection of the second holographic region 120 toward the mirror reflection mechanism 220 is located within the area where the mirror reflection mechanism 220 is located.

[0065] The specific structure of the specular reflection mechanism 220 is not limited in this embodiment. For example, the specular reflection mechanism 220 may include an independent plane mirror structure with a reflective surface to achieve specular reflection. Alternatively, the specular reflection mechanism 220 may include a specular reflection coating, a specular reflection film, or other structures, both of which can form a reflective surface to achieve specular reflection. The specular reflection coating and film can be made of any coating or film material, as long as the requirements are met.

[0066] Optionally, for the mirror reflection mechanism 220 to have its reflecting surface parallel to the bearing surface, the mirror reflection mechanism 220 can be mounted on the clamping mechanism 210, such that the reflecting surface is higher or lower than the bearing surface in a direction perpendicular to the bearing surface. This can be achieved by appropriately setting the position of the plane mirror if the mirror reflection mechanism 220 uses an independent plane mirror structure; if the mirror reflection mechanism 220 uses a mirror reflection coating, mirror reflection film, or similar structure, the mirror reflection coating, mirror reflection film, etc., can be appropriately placed on other surfaces of the clamping mechanism 210 that are parallel to the bearing surface and higher or lower than the bearing surface.

[0067] Optionally, for the mirror reflection mechanism 220 to have its reflecting surface and bearing surface coplanar, the mirror reflection mechanism 220 can be mounted on the bearing surface of the clamping mechanism 210. In this manner, if the mirror reflection mechanism 220 uses an independent plane mirror structure, this can be achieved by appropriately setting the position of the plane mirror (for example, besides appropriately mounting it on other structures on the clamping mechanism 210 to make the reflecting surface of the plane mirror coplanar with the bearing surface, in some other ways, a groove can be cut into the bearing surface to embed the plane mirror into the groove, making the reflecting surface of the plane mirror coplanar with the bearing surface); if the mirror reflection mechanism 220 uses a mirror reflection coating, mirror reflection film, or other structures, the mirror reflection coating, mirror reflection film, etc., can be appropriately placed on the clamping mechanism 210 (for example, a mirror reflection coating can be applied to the bearing surface or a mirror reflection film can be placed). Alternatively, the mirror reflection mechanism 220 can also be placed on other surfaces of the clamping mechanism 210 that are coplanar with the bearing surface.

[0068] It should be understood that the method by which the mirror reflection mechanism 220 is mounted on the clamping mechanism 210 can be arbitrarily selected as needed, as long as the requirements are met. For example, methods such as bonding or coating can be used.

[0069] The shape of the mirror reflection mechanism 220 is not specifically limited in this embodiment. (Refer to...) Figure 3 The example shown can be a rounded rectangle. Alternatively, it can be a regular shape such as a rectangle or a circle, or it can be other irregular shapes.

[0070] Optionally, refer to Figure 3 As shown in the example, the clamping device 200 may include a plurality of specular reflection mechanisms 220 to adapt to a plurality of second holographic regions 120 of the computational holographic element 100. Figure 2As shown, in this example, the clamping device 200 may include two specular reflection mechanisms 220. Optionally, the positions of the multiple specular reflection mechanisms 220 on the clamping device 200 correspond to the positions of the multiple second holographic regions 120 on the computational holographic element 100, respectively. It should be understood that the multiple specular reflection mechanisms 220 may adopt the same structure or different structures, as long as they meet the usage requirements. In this embodiment of the present disclosure, the clamping device 200 uses multiple specular reflection mechanisms 220 adapted to the multiple second holographic regions 120 of the computational holographic element 100 to achieve cooperative use, which can more effectively improve the equipment assembly accuracy of the detection system 400, so as to facilitate more accurate detection of aspherical elements.

[0071] The detection system 400 will be described in detail below.

[0072] In this detection system 400, the interferometer 300 can be any suitable interferometer. (Refer to...) Figure 1 As shown, the interferometer 300 of the detection system 400 may include a standard spherical mirror 310. The interferometer 300 can emit a first spherical wave to the computational holographic element 100 through the standard spherical mirror 310.

[0073] In this testing system 400, the component under test can be clamped by the clamping mechanism 210 of the clamping device 200. The component under test can be an aspherical component 10. The aspherical component 10 is placed against the bearing surface of the clamping mechanism 210, so that the bearing surface supports the aspherical component 10. When the aspherical component 10 is supported by the bearing surface, the optical axis of the aspherical component 10 is perpendicular to the bearing surface.

[0074] In the detection system 400, the first spherical wave emitted by the interferometer 300 is incident on the first holographic region 110, the second holographic region 120, and the third holographic region 130 of the computational holographic element 100 from the first side.

[0075] In the detection system 400, the interferometer 300 also receives the first interference light generated by the first return light reflected back from the first holographic region 110 and the reference light of the interferometer 300, forming the first interference fringes.

[0076] Optionally, the first spherical wave emitted by the interferometer 300 is transmitted from the first side of the computational holographic element 100 to the first holographic region 110. The first holographic region 110 of the reflective grating structure reflects the incident first spherical wave, causing the reflected first return light to return to the interferometer 300 along the original optical path. The first return light interferes with the reference light inside the interferometer 300, generating first interference light. The interferometer 300 receives the first interference light, forming first interference fringes. During the equipment setup and adjustment stage of the detection system 400 for aspherical element detection, the detection system 400 can be adjusted according to the state of the first interference fringes to conveniently adjust the position and tilt of the computational holographic element 100 relative to the standard spherical mirror 310 of the interferometer 300, so that the optical axis of the computational holographic element 100 can be aligned with the optical axis of the interferometer 300, facilitating accurate aspherical element detection.

[0077] In the detection system 400, the interferometer 300 also receives the second interference light generated by the second return light transmitted from the second holographic region 120, reflected by the mirror reflection mechanism 220, and then transmitted back from the second holographic region 120, and the reference light of the interferometer 300, forming a second interference fringe.

[0078] Optionally, the first spherical wave emitted by the interferometer 300 is incident on the second holographic region 120 from the first side of the computational holographic element 100. The second holographic region 120, with its transmission grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100 and converts it into a plane wave. The plane wave can be reflected back to the second holographic region 120 via the mirror reflection mechanism 220 on the clamping device 200. The light reflected back to the second holographic region 120 is then transmitted through the second holographic region 120 to form a second return light. The second return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300 to generate a second interference light. The interferometer 300 receives the second interference light to form a second interference fringe. Based on the state of the second interference fringe, the tilt of the aspherical element 10 under test relative to the interferometer 300 can be adjusted so that the optical axis of the aspherical element 10 under test is aligned with the optical axis of the interferometer 300 and the optical axis of the computational holographic element 100, thereby facilitating accurate aspherical element detection.

[0079] In the detection system 400, the interferometer 300 also receives the third interference light generated by the third return light transmitted from the third holographic region 130, reflected by the aspherical element 10 to be tested, and then transmitted back from the third holographic region 130, and the reference light of the interferometer 300, forming a third interference fringe.

[0080] Optionally, the first spherical wave emitted by the interferometer 300 is incident on the third holographic region 130 from the first side of the computational holographic element 100. The third holographic region 130, with its transmission grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100 and converts it into a second spherical wave with a focal point. The second spherical wave can be reflected by the aspherical element under test, and the light reflected back to the third holographic region 130 is then transmitted through the third holographic region 130 to form a third return light. The third return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300, generating a third interference light. The interferometer 300 receives the third interference light, forming a third interference fringe. During the equipment setup and adjustment stage of the detection system 400 for aspherical element detection, the axial distance between the aspherical element under test 10 and the computational holographic element 100 can be adjusted according to the state of the third interference fringe to facilitate the detection of the vertex of the aspherical element under test.

[0081] Based on this, the detection system 400 of the above embodiment emits a first spherical wave through the interferometer 300 and receives: a first interference fringe formed by the first return light reflected from the first holographic region of the computational holographic element 100 and the first interference light generated by the reference light of the interferometer 300; a second interference fringe formed by the second interference light generated by the second return light transmitted through the second holographic region 120 of the computational holographic element 100, reflected by the mirror reflection mechanism 220 of the clamping device 200 provided in the second aspect, and then transmitted through the second holographic region 120 and the reference light of the interferometer 300; and a third interference fringe formed by the third interference light generated by the third return light transmitted through the third holographic region 130 of the computational holographic element 100, reflected by the aspherical element 10 to be tested, and then transmitted through the third holographic region 130 and the reference light of the interferometer 300. This allows for more accurate and convenient equipment assembly and adjustment of the aspherical element detection system based on the first interference fringe, the second interference fringe, and the third interference fringe, as well as more accurate aspherical element detection. Furthermore, it can be effectively applied to the detection of various aspherical components with symmetrical or asymmetrical surfaces, and can achieve high accuracy in all cases.

[0082] In some optional embodiments, the computational holographic element 100 in the detection system 400 further includes a fourth holographic region 140, which is formed on at least one of the first and second sides of the computational holographic element 100. The fourth holographic region 140 can be configured as a transmissive grating and can transmit a first spherical wave incident from the first side to the fourth holographic region 140 through the second side and convert it into a preset standard aspherical wave. Based on this, the interferometer 300 is further configured to: receive a fourth interference light generated by a fourth return light transmitted through the fourth holographic region 140, reflected by the aspherical element 10 under test, and then transmitted back through the fourth holographic region, and the reference light of the interferometer, forming a fourth interference fringe.

[0083] Optionally, the first spherical wave emitted by the interferometer 300 is incident on the fourth holographic region 140 from the first side of the computational holographic element 100. The fourth holographic region 140, with its transmission grating structure, transmits the incident first spherical wave from the second side of the computational holographic element 100 and converts it into a preset standard aspherical wave. This preset standard aspherical wave can be reflected by the aspherical element under test, and the light reflected back to the fourth holographic region 140 is then transmitted through the fourth holographic region 140 to form a fourth return light. The fourth return light returns to the interferometer 300 and interferes with the reference light inside the interferometer 300, generating a fourth interference light. The interferometer 300 receives the fourth interference light, forming a fourth interference fringe. Interference detection (e.g., zero-position interference detection) can be performed on the aspherical element under test based on the state of the fourth interference fringe.

[0084] The fourth holographic region 140 has been described in detail in the previous section on the embodiment of the computational holographic element 100, and can be understood by referring to the previous text. It will not be repeated here.

[0085] Based on this, the detection system 400 receives the fourth interference fringe formed by the fourth return light transmitted from the fourth holographic region 140, reflected by the aspherical element 10 under test, and then transmitted back from the fourth holographic region, and the fourth interference light generated by the reference light of the interferometer 300, thereby realizing the interference detection of the aspherical element 10 under test.

[0086] Optionally, when using the detection system 400 of this embodiment to detect the aspherical element 10 under test, in one application scenario, the vertex position of the aspherical element 10 under test can be detected.

[0087] The detection methods of the detection system 400 in some embodiments of this disclosure will now be described. Figure 4 This is a flowchart of some exemplary aspherical component detection methods in the embodiments of this disclosure. The aspherical component detection methods provided in some embodiments of this disclosure employ the detection system 400 provided in the above embodiments. (Refer to...) Figure 4 As shown, the aspherical element detection method includes steps S402, S404, and S406, specifically:

[0088] S402: Adjust at least one of the position and orientation of the computational holographic element relative to the interferometer until the first interference fringe satisfies the first condition, so as to adjust the computational holographic element to a preset position.

[0089] Reference Figure 1In the setup and adjustment phase of the detection system 400 shown, the interferometer 300 is activated, causing the interferometer 300 to continuously emit a first spherical wave to the computational holographic element 100. As described above, the interferometer 300 can obtain the first interference fringe. In this phase, at least one of the position and orientation of the computational holographic element 100 relative to the interferometer 300 can be adjusted until the first interference fringe satisfies the first condition, so as to adjust the computational holographic element 100 to the preset position.

[0090] Optionally, the first condition may be a condition used to determine that the first interference fringes have reached the desired flatness and sparseness. In some optional embodiments, step S402 may include: adjusting at least one of the position and orientation of the computational holographic element relative to the interferometer until the first interference fringes are flat and the number of fringes is within a predetermined number, thereby adjusting the computational holographic element 100 to a preset position. At this point, the first interference fringes are considered to have reached a flat and sparse state. At this preset position, the optical axis of the computational holographic element 100 is aligned with the optical axis of the interferometer 300 and there is no defocus aberration. The position and tilt of the computational holographic element 100 relative to the standard spherical mirror 310 of the interferometer 300 can be considered to have been adjusted. The predetermined number of fringes can be selected according to the accuracy requirements, for example, it can be less than or equal to 2 fringes, for example, it can be selected as 2 fringes or 1 fringe. This helps to ensure the equipment assembly accuracy and the detection accuracy of the aspherical element.

[0091] S404: Adjust the orientation of the clamping device until the second interference fringe satisfies the second condition, so that the optical axis of the aspherical element to be measured located on the clamping device is aligned with the optical axis of the interferometer.

[0092] Reference Figure 1 In the setup and adjustment phase of the detection system 400, the interferometer 300 continuously emits a first spherical wave to the computational holographic element 100. As described above, the interferometer 300 can obtain a second interference fringe. During this phase, the orientation of the clamping device 200 can be adjusted until the second interference fringe satisfies the second condition, so that the optical axis of the aspherical element 10 under test located on the clamping device 200 is aligned with the optical axis of the interferometer 300.

[0093] In some alternative embodiments, step S404 may include: adjusting the orientation of the clamping device 200 until the second interference fringe is in a zero-fringe state, so that the optical axis of the aspherical element 10 to be tested located on the clamping device 200 is aligned with the optical axis of the interferometer 300.

[0094] When the second interference fringe appears as a zero-fringe state, it is considered that the reflecting surface of the mirror reflection mechanism 220 of the clamping device 200 is perpendicular to the optical axis of the computational holographic element 100. Since the reflecting surface is parallel or coplanar with the bearing surface of the clamping mechanism 210, and the optical axis of the aspherical element 10 under test is perpendicular to the bearing surface, at this time, the optical axis of the aspherical element 10 under test located on the clamping device 200 is aligned with the optical axis of the computational holographic element 100 and the optical axis of the interferometer 300. The tilt of the aspherical element 10 under test relative to the interferometer 300 can be considered to have been adjusted, facilitating the next step of equipment assembly and aspherical element testing.

[0095] Based on this, by adjusting the posture of the clamping device 200 until the second interference fringe appears as a zero fringe state, the optical axis of the aspherical element 10 to be tested located on the clamping device 200 can be effectively aligned with the optical axis of the interferometer 300, thereby facilitating the adjustment of the tilt of the aspherical element 10 to be tested relative to the computational holographic element 100, which is beneficial to improving the detection accuracy of the aspherical element.

[0096] Reference Figure 5 As shown, this diagram illustrates the measurement of the vertex position of the aspherical element 10 under test in both tilted and non-tilted states (i.e., the optical axis of the aspherical element 10 is aligned with the optical axis of the interferometer 300). Figure 5 As shown, OA represents the optical axis of the interferometer 300; the solid line represents the untilted state of the aspherical element 10 under test, with A being the vertex position in the untilted state; the dashed line represents the tilted state of the aspherical element 10 under test, with A' being the vertex position in the tilted state. In the untilted state, the vertex position A of the aspherical element can be easily found during scanning using the convergence point formed by the third holographic region 130 of the holographic element 100. However, in the tilted state, it is difficult to accurately find the vertex position A' using the convergence point formed by the third holographic region 130 (it should be understood that...). Figure 5 Point A' is located on the dashed line. Because the tilted state introduces coma and astigmatism, it leads to significant testing errors, making it difficult to detect the vertex position of the aspherical element 10 under test. Therefore, aligning the optical axes of the interferometer 300, the holographic element 100, and the aspherical element 10 under test through steps S402 and S404 in this embodiment is an important means to improve the vertex detection accuracy of the aspherical element.

[0097] S406: Adjust the position of the clamping device until the third interference fringe satisfies the third condition in order to determine the vertex position of the aspherical element to be measured.

[0098] Reference Figure 1During testing, the interferometer 300 continuously emits a first spherical wave to the computational holographic element 100 in the detection system 400 shown. As can be seen from the above description, the interferometer 300 can obtain a third interference fringe. At this stage, the orientation of the clamping device 200 can be adjusted until the third interference fringe meets the third condition, so as to accurately determine the vertex position on the aspherical element 10 to be tested.

[0099] In some alternative implementation schemes, refer to Figure 6 The flowchart shown includes steps S4061 and S4062, specifically:

[0100] S4061: Adjust the position of the clamping device until the third interference fringe is the sparsest;

[0101] S4062: The position of the focal point of the second spherical wave when the third interference fringes are the sparsest on the aspherical element under test is determined as the vertex position of the aspherical element under test.

[0102] Based on the characteristics of aspherical surfaces, the vertices of an aspherical surface are extreme points. When the convergence point of the second spherical wave transmitted and converted by the third holographic region 130 coincides with the vertex position of the aspherical element 10 under test, the sparsest third interference fringes can be obtained. Therefore, in the above-described optional implementation of this disclosure, by adjusting the position of the clamping device 200, the position of the convergence point of the second spherical wave on the aspherical element under test when the third interference fringes are most sparse is found, and this position is determined as the vertex position of the aspherical element 10 under test, thereby effectively realizing the detection of the vertex position of the aspherical element and ensuring the accuracy of the detection results.

[0103] This disclosure does not limit the specific manner in which the position of the clamping device 200 is adjusted in step S4061 until the third interference fringe is the sparsest.

[0104] In some alternative implementation schemes, refer to Figure 7 The flowchart shown includes steps S4061A to S4061C, specifically:

[0105] S4061A: Adjust the position of the clamping device along the axis of the interferometer until the third interference fringe is the sparsest during the adjustment along the axis of the interferometer.

[0106] To accurately locate the vertex position of the aspherical element 10 under test, it is necessary to determine the vertex position from three spatial directions (e.g., denoted as the first direction, the second direction, and the third direction, respectively considered as the x, y, and z directions, and the three directions being mutually perpendicular). The axis of the interferometer 300 (i.e., the optical axis direction) can be defined as the third direction. By adjusting the position of the clamping device 200 along the axis of the interferometer 300 (i.e., the third direction), the position where the third interference fringe is sparsest during the adjustment along the axis of the interferometer 300 is found, thus determining the vertex position of the aspherical element 10 under test on the axis of the interferometer 300 (i.e., the third direction). Then, using this position as a reference, the vertex position can be further detected in several other directions (i.e., the first direction and the second direction).

[0107] The plane orthogonal to the z-direction (i.e., the axis of the interferometer 300) is the plane formed by the first and second directions. Next, the vertex positions in the first and second directions can be found within this plane using a cross-scan method.

[0108] S4061B: In a plane orthogonal to the axis of the interferometer, adjust the position of the clamping device along the first direction until the third interference fringe is the sparsest during the adjustment in the first direction.

[0109] For example, refer to Figure 8 As shown, the first direction is the direction of path 1. The position of the clamping device 200 can be adjusted multiple times along path 1 so that the focal point of the second spherical wave transmitted and converted by the third holographic region 130 of the holographic element 100 is scanned along path 1 for the aspherical element 10 under test until the position where the third interference fringes are sparsest during the adjustment in the first direction is found. It should be understood that Figure 8 Path 1 shown is merely an example for ease of understanding.

[0110] S4061C: In a plane orthogonal to the axis of the interferometer, adjust the position of the clamping device along a second direction perpendicular to the first direction until the third interference fringe is the sparsest during the adjustment in the second direction.

[0111] For example, refer to Figure 8 As shown, the second direction is the direction of path 2. The position of the clamping device 200 can be adjusted multiple times along path 2 so that the focal point of the second spherical wave transmitted and converted by the third holographic region 130 of the holographic element 100 is scanned along path 2 to the aspherical element 10 under test until the position where the third interference fringes are sparsest during the adjustment in the second direction is found. It should be understood that Figure 8 Path 2 shown is merely an example for ease of understanding.

[0112] It should be noted that the order of steps S4061B and S4062C can be arbitrarily chosen; S4061B can be followed by S4062C, or S4061C can be followed by S4061B. For example, taking S4061B first and S4062C last as an example, after finding the position where the third interference fringe is sparsest during the adjustment process in the first direction in S4061B, this position is used as a reference, and then S4061C is performed. That is, using this reference position as the perpendicular foot, the position of the clamping device 200 is adjusted along the second direction perpendicular to the first direction until the position where the third interference fringe is sparsest during the adjustment process in the second direction is found. The position where the third interference fringe is sparsest during the adjustment process in the second direction is then determined. Thus, the position of the convergence point of the second spherical wave on the aspherical element under test when the third interference fringe is sparsest can be determined as the vertex position of the aspherical element under test. For example, taking S4061C first and S4061B second, after finding the position where the third interference fringe is sparsest during the adjustment process in the second direction in S4061C, this position can be used as a reference. Then, S4061B is performed, that is, using this reference position as the foot of the perpendicular, the position of the clamping device 200 is adjusted along the first direction perpendicular to the second direction until the position where the third interference fringe is sparsest during the adjustment process in the first direction is found. The position where the third interference fringe is sparsest during the adjustment process in the first direction can be used to determine the position of the convergence point of the second spherical wave on the aspherical element under test when the third interference fringe is sparsest, which is the vertex position of the aspherical element under test.

[0113] Optionally, the above steps S4061A to S4061C can be performed multiple times to further improve the detection accuracy of the vertex position detection of the aspherical element 10 under test.

[0114] Based on this, in the optional implementation of steps S4061A to S4061C in this embodiment, by adjusting the position of the clamping device along the axis of the interferometer, the third interference fringe is made sparsest during the adjustment along the axis of the interferometer. Then, in a plane orthogonal to the axis of the interferometer, the position of the clamping device is adjusted along the first direction and the second direction respectively until the third interference fringe is sparsest. This allows for accurate and effective determination of the position where the third interference fringe is sparsest. Therefore, the vertex position of the aspherical element 10 under test can be determined based on the position of the convergence point of the second spherical wave on the aspherical element under test when the third interference fringe is sparsest. This ensures the accuracy of the detection result of the vertex position of the aspherical element and improves the detection precision.

[0115] It should be understood that when performing aspherical component detection using the aspherical component detection method described in steps S402 to S406 of the embodiments of this disclosure, equipment assembly and adjustment can be easily and accurately achieved, and the vertex position of the aspherical component 10 to be tested can be precisely detected, thereby improving detection accuracy. Furthermore, it is effectively applicable to the detection of various aspherical components, whether symmetrical or asymmetrical, and can achieve high accuracy in all cases.

[0116] Furthermore, the aspherical detection method of this disclosure is a non-contact interference detection method, which can reduce surface damage to the aspherical element 10 under test.

[0117] It is understood that the above descriptions of various aspects of the embodiments of this disclosure are merely optional exemplary descriptions of the technical solutions of the embodiments of this disclosure, and are not intended to limit the embodiments of this disclosure in any way.

[0118] The optional embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited thereto. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure. The various technical features included in the different embodiments of the present disclosure can be combined in any suitable manner. To avoid unnecessary repetition, the present disclosure will not describe the various possible combinations separately. However, these simple modifications and combinations should also be regarded as the content disclosed in the present disclosure and all fall within the protection scope of the present disclosure.

[0119] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". It should be noted that the concepts of "first", "second", etc., mentioned in the embodiments of this disclosure are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies. It should be noted that the modifications of "a" and "a plurality" mentioned in the embodiments of this disclosure are illustrative and not restrictive, and those skilled in the art should understand that unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this disclosure, and are not intended to limit them. Although the embodiments of this disclosure have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 this disclosure.

Claims

1. A computational holographic element, comprising: The first holographic region, the second holographic region, and the third holographic region are formed on at least one of a first side and a second side of the computational holographic element, the first side and the second side being two sides of the computational holographic element opposite in a thickness direction; The first holographic region is configured as a reflection grating and is capable of reflecting a first spherical wave incident to the first holographic region from the first side along an original light path; The second holographic region is configured as a transmission grating and is capable of transmitting the first spherical wave incident to the second holographic region from the first side from the second side and converting the first spherical wave into a plane wave; The third holographic region is configured as a transmission grating and is capable of transmitting the first spherical wave incident to the third holographic region from the first side from the second side and converting the first spherical wave into a second spherical wave with a converging focal point.

2. The computer-generated holographic element of claim 1, wherein, The computational holographic element further comprises a fourth holographic region formed on at least one of the first side and the second side; The fourth holographic region is configured as a transmission grating and is capable of transmitting the first spherical wave incident to the fourth holographic region from the first side from the second side and converting the first spherical wave into a preset standard aspheric wave.

3. The computer-generated holographic element of claim 2, wherein, The first holographic region and the third holographic region are annular and are arranged around the outside of the fourth holographic region, and the second holographic region is located on at least one of the first holographic region and the third holographic region.

4. A clamping device comprising: a clamping mechanism configured to be capable of clamping a to-be-measured aspheric element and comprising a bearing surface capable of bearing the to-be-measured aspheric element when the to-be-measured aspheric element is clamped; a mirror reflection mechanism arranged on the clamping mechanism, the mirror reflection mechanism being used for mirror reflecting the plane wave transmitted and converted by the second holographic region of the computational holographic element according to any one of claims 1-3; wherein the mirror reflection mechanism satisfies any one of the following conditions: a reflection surface of the mirror reflection mechanism is parallel to the bearing surface; the reflection surface of the mirror reflection mechanism is coplanar with the bearing surface.

5. The clamping device of claim 4, wherein, The position at which the mirror reflection mechanism is arranged on the clamping device corresponds to the position at which the second holographic region is arranged on the computational holographic element.

6. An inspection system for inspecting an aspherical element under test, the inspection system comprising: an interferometer, the computational holographic element according to any one of claims 1-3, and the clamping device according to claim 4 or 5, which are arranged in sequence; wherein the clamping device is used for clamping the to-be-measured aspheric element; the interferometer is used for emitting a first spherical wave to the computational holographic element, and the interferometer is further used for: receiving first return light reflected back by the first holographic region and first interference light generated by the reference light of the interferometer to form first interference fringes; receiving second return light transmitted by the second holographic region, reflected by the mirror reflection mechanism, and then transmitted by the second holographic region and second interference light generated by the reference line of the interferometer to form second interference fringes; and The third return light transmitted by the third holographic region, reflected by the to-be-tested aspheric element, and transmitted by the third holographic region again, and reference light of the interferometer generate third interference light, and third interference fringes are formed.

7. The detection system of claim 6, wherein, The computer-generated holographic element further comprises a fourth holographic region formed on at least one of the first side and the second side; The fourth holographic region is configured as a transmission grating and can transmit and convert the first spherical wave incident on the fourth holographic region from the first side to a preset standard aspheric wave through the second side; The interferometer is further configured to: receive fourth return light transmitted by the fourth holographic region, reflected by the to-be-tested aspheric element, and transmitted by the fourth holographic region again, and reference light of the interferometer generate fourth interference light, and fourth interference fringes are formed.

8. An aspheric element detection method using the detection system of claim 6 or 7, the method comprising: adjusting at least one of a position and an attitude of the computer-generated holographic element relative to the interferometer until the first interference fringes satisfy a first condition, so as to adjust the computer-generated holographic element to a preset position; adjusting an attitude of the clamping device until the second interference fringes satisfy a second condition, so as to align an optical axis of the to-be-tested aspheric element located on the clamping device with an optical axis of the interferometer; adjusting a position of the clamping device until the third interference fringes satisfy a third condition, so as to determine a vertex position of the to-be-tested aspheric element.

9. The method of claim 8, wherein, The adjusting of the attitude of the clamping device until the second interference fringes satisfy the second condition so as to align the optical axis of the to-be-tested aspheric element located on the clamping device with the optical axis of the interferometer comprises: adjusting the attitude of the clamping device until the second interference fringes present a zero-fringe state, so as to align the optical axis of the to-be-tested aspheric element located on the clamping device with the optical axis of the interferometer.

10. The method of claim 8 or 9, wherein, The adjusting of the position of the clamping device until the third interference fringes satisfy the third condition so as to detect the vertex position of the to-be-tested aspheric element comprises: adjusting the position of the clamping device until the third interference fringes are most sparse; determining, as the vertex position of the to-be-tested aspheric element, a position of a converging focus of the second spherical wave on the to-be-tested aspheric element when the third interference fringes are most sparse.

11. The method of claim 10, wherein, The adjusting of the position of the clamping device until the third interference fringes are most sparse comprises: adjusting the position of the clamping device along an axial direction of the interferometer until the third interference fringes are most sparse in the adjusting along the axial direction of the interferometer; adjusting the position of the clamping device in a first direction in a plane orthogonal to the axial direction of the interferometer until the third interference fringes are most sparse in the adjusting in the first direction; adjusting the position of the clamping device in a second direction perpendicular to the first direction in the plane orthogonal to the axial direction of the interferometer until the third interference fringes are most sparse in the adjusting in the second direction.

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