Large-aperture long-focal-distance axis lens shape integrated detection device and detection method

Abstract

The invention discloses an integrated detection device and method for the shape of a large-aperture long-focal-distance axis lens, belongs to the shape detection of an off-axis lens in precision optics, and aims to solve the technical problem that the shape parameters of the off-axis lens cannot be integrally detected. The device comprises a large-aperture plane interferometer, a to-be-measured lens, a large-aperture computer-generated hologram plate, an attitude alignment module and a precise distance measurement module. A main test area, an alignment area and an off-axis calibration area are arranged on the large-aperture computer-generated hologram plate; and the attitude alignment module and the precision distance measurement module are respectively configured on a tool of a lens to be measured and a tool of a computer-generated hologram plate. The detection method comprises the following steps of: obtaining a background wavefront of the computer-generated hologram detection cavity by adopting a large-aperture standard spherical lens; the pose adjustment of the large-aperture computer-generated hologram plate and the to-be-measured lens is completed based on the large-aperture plane interferometer; measuring the transmission wavefront of the lens to be measured and deducting the background wavefront; and measuring and calculating the rear intercept of the to-be-measured lens, and calculating the off-axis amount by combining the off-axis angle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of precision optical detection, and relates to detection of an off-axis lens, in particular to a large-aperture long-focus off-axis lens shape and property integrated detection device and a detection method. BACKGROUND

[0002] An off-axis lens is a special lens, which can modulate the wavefront of incident light by controlling the phase distribution of each point on the lens, so that the light at different positions can be focused at a specific off-axis position after passing through the lens. Compared with on-axis optical elements, the off-axis lens has the advantages of high light flux, low stray light and high contrast because its geometric center axis deviates from the optical axis, and is widely used in large optical systems such as astronomical telescopes, airborne imaging devices, spectrometers, high-power laser devices, etc.

[0003] With the increasing performance requirements of optical systems, the precision machining and detection of lenses face greater challenges, especially the detection of key shape and property parameters (transmission wavefront, back aperture, off-axis amount) of large-aperture long-focus off-axis lenses, which is still an engineering problem to be solved in the field of modern advanced optical manufacturing.

[0004] In the prior art, large-aperture long-focus off-axis lenses widely used in optical systems usually have an aperture not less than φ400mm, a back aperture ranging from tens of meters to thousands of meters, and an off-axis amount generally not less than one third of the measured aperture. The key problem faced by transmission wavefront detection is the difficulty in correcting the asymmetric aberration of the system, the large error in the installation and adjustment of the test light path, the limited measurement space due to the long test light path, and the large environmental disturbance introduced. The back aperture detection has insufficient focusing and ranging accuracy from tens of meters to thousands of meters. The off-axis amount cannot be directly measured due to the non-embodiment of the lens optical axis. Traditional detection technology is usually positioned to solve the detection of single parameters (such as transmission wavefront or back aperture), but the constraint conditions and element states of each parameter detection system are not unified, resulting in low measurement efficiency and inability to accurately evaluate the performance of the optical element under service conditions.

[0005] The application No. 201610951248.5 discloses a detection device and method for measuring long-focus lens transmission wavefront by using a computer holography method. The device includes an interferometer, a measured long-focus lens, and a Fresnel zone plate arranged in sequence along the direction away from the interferometer. The Fresnel zone plate is a concentric ring zone. When the collimated parallel light output by the interferometer passes through the standard plane mirror at the end of the interferometer, a part of the collimated parallel light is reflected by the standard plane mirror to form a standard reference light beam, and the other part of the collimated parallel light passes through the standard plane mirror and the measured long-focus lens in sequence, is reflected on the Fresnel zone plate, and returns along the original path to form a test light beam. The test light beam and the standard reference light beam generate interference fringes. The detection steps include: making the Fresnel zone plate, measuring the background wavefront, measuring the combined wavefront, and data processing. Before placing the measured long-focus lens, the Fresnel zone plate is equivalent to a reflection flat plate, and the reflection wavefront reflects the background error of the interference detection. After placing the measured long-focus lens, the Fresnel zone plate generates a diffraction wavefront to provide a reference spherical wave for detecting the lens transmission wavefront. The transmission wavefront can be deducted from the background error, the transmission wavefront detection error introduced by the Fresnel zone plate processing can be deducted, and the detection precision is improved. The detection device and method can measure the transmission wavefront of the measured long-focus lens. However, since the waveband plate pattern is a concentric ring zone, it can only measure the transmission wavefront of the coaxial lens, and cannot measure the transmission wavefront, back intercept, off-axis amount and other parameters of the off-axis lens. In addition, the 0th order diffraction light and the 1st order diffraction light as the system background will be reflected into the interferometer, introducing test stray light, causing the center of the test data to be missing or abnormal. In addition, the 0th order reflection wavefront of the waveband plate is obtained as the system background wavefront, the collimated light of the interferometer passes through the measured lens and is incident on the waveband plate, which will introduce defocus and spherical aberration to the measurement result, and the wavefront measurement error is large.

[0006] The application patent with the application number 202010172017.0 also discloses a method for measuring lens focal length based on computer-generated hologram, which comprises the following steps: 1) design of CGH, according to the curvature radius of the front and back surfaces of the measured lens, the center thickness, the material of the lens and the distance between the measured lens and the CGH, the radius parameters of each ring of the CGH are obtained, so that the CGH is made; 2) acquisition of background wavefront, using a plane interferometer, the 0-order wavefront of the CGH is measured multiple times, and the average is taken as the background wavefront; 3) acquisition of the distance between the measured lens and the CGH, using a plane interferometer, the measured lens is placed between the standard plane mirror of the plane interferometer and the CGH, the wavefront of the lens is measured multiple times, and the distance between the lens and the CGH is measured at the same time, the background wavefront is subtracted from each transmission wavefront, the relationship between the defocus amount and the distance is calculated, and the optimal distance is obtained by least square fitting; 4) acquisition of lens focal length, using a spherical interferometer, the 1st-order curvature radius of the CGH is measured first, and then the focal length of the measured lens is obtained according to the curvature radius of the CGH and the distance between the measured lens and the CGH. Although the method measures the wavefront of the lens multiple times and measures the distance between the lens and the CGH at the same time, each measurement needs to move and adjust the elements, resulting in low measurement efficiency; when the spherical interferometer is used to measure the curvature radius and the back intercept, since the aperture of the spherical lens of the spherical interferometer is less than 10 mm, only CGH with converging characteristics can be measured, and CGH with diverging characteristics cannot be measured, resulting in limited measurement range, and the spherical interferometer needs to calibrate the curvature radius of the CGH, which limits the calibration range of the curvature radius of the non-visible light CGH; in addition, the measured lens is not limited during the multiple moving measurement process, which will also introduce different adjustment errors during the multiple moving transparent measurement process, affecting the accurate result of the wavefront defocus aberration.

[0007] Therefore, it is necessary to provide a device and method for integrally detecting the shape and performance parameters (transmission wavefront, back intercept and off-axis amount) of an off-axis lens, and to improve the measurement accuracy of the shape and performance parameters of the off-axis lens. SUMMARY

[0008] The purpose of the present application is to solve the technical problem that the prior art cannot integrally detect the shape and performance parameters (transmission wavefront, back intercept and off-axis amount) of an off-axis lens, and to provide a large-aperture long-focal-distance off-axis lens shape and performance integrally detecting device and method, which can measure the shape and performance parameters such as the transmission wavefront, back intercept and off-axis amount of the off-axis lens, and improve the measurement accuracy of the shape and performance parameters.

[0009] In order to achieve the above purpose, the present application specifically adopts the following technical scheme: A large-aperture long-focal-distance off-axis lens shape and performance integrally detecting device, comprising a large-aperture plane interferometer, a measured lens, a large-aperture computer-generated hologram plate, an attitude alignment module and a precise distance measuring module. The large-aperture computer holographic plate is etched with a main test area, an alignment area, and an off-axis amount calibration area on the surface. The main test area is located within the clear aperture of the large-aperture computer holographic plate and is used for compensating for the aberration of the measurement light path. The alignment area is located at three corner positions outside the clear aperture of the large-aperture computer holographic plate and is used for monitoring the test posture of the large-aperture computer holographic plate. The off-axis amount calibration area is rectangular and is located at the edge of the substrate of the large-aperture computer holographic plate along the off-axis direction of the lens and is used for calibrating the off-axis amount of the lens to be measured. The posture alignment module includes a collimated light aiming assembly and an interference alignment assembly. During posture alignment, the posture of the lens to be measured is adjusted so that the collimated light emitted by the collimated light aiming assembly is reflected by the surface of the lens to be measured and then returns to the collimated light aiming assembly, thereby completing coarse alignment of the lens posture. Then, the posture of the lens to be measured is finely aligned by the interference fringes of the interference alignment assembly. The precise distance measuring module is used for measuring the distance between the lens to be measured and the large-aperture computer holographic plate. The measurement light path is as follows: The large-aperture plane interferometer emits a parallel laser beam. Part of the parallel laser beam is reflected by the reference mirror of the large-aperture plane interferometer to form a reference beam. Another part of the parallel laser beam passes through the reference mirror of the large-aperture plane interferometer to form a measurement beam. The measurement beam passes through the lens to be measured and then enters the large-aperture computer holographic plate. The measurement beam is reflected by the large-aperture computer holographic plate and then returns to the large-aperture plane interferometer along the original path. The measurement beam and the reference beam form interference fringes, and the wavefront distribution is obtained by analyzing the interference fringes. Then, the lens to be measured is axially moved so that the transmitted wavefront off-focus aberration of the lens to be measured is not greater than λ / 20. The distance between the lens to be measured and the large-aperture computer holographic plate is measured by using the precise distance measuring module. A standard lens with a known back intercept is used to replace the lens to be measured. The above measurement is repeated, and the back intercept and the off-axis amount of the lens to be measured are calculated according to the distance between the lens to be measured and the large-aperture computer holographic plate, the distance between the standard lens and the large-aperture computer holographic plate, and the back intercept of the standard lens.

[0010] Further, the material of the substrate of the large-aperture computer holographic plate is fused quartz or microcrystalline material, and the aperture of the large-aperture computer holographic plate is greater than or equal to the aperture of the lens to be measured.

[0011] Further, the large-aperture computer holographic plate is inclined, and the inclination angle between the normal line of the large-aperture computer holographic plate and the optical axis of the measurement beam is The condition is satisfied: The large-aperture computer holographic plate is inclined so that the 0th-order reflected light spot of the large-aperture computer holographic plate deviates from the imaging field of view of the large-aperture plane interferometer, thereby eliminating the influence of the non-working order stray light of the computer hologram on the measurement result.

[0012] Further, the main test area (32) diffracts the wave of order -1, and the graphical phase is characterized by: ; wherein, denotes the Zernike term number, denotes the i-th Zernike standard polynomial, denotes the i-th Zernike standard polynomial, denotes the i-th Zernike standard polynomial, denotes the normalized radial ray coordinate, denotes the normalized angular ray coordinate.

[0013] Further, the alignment area adopts an equal-interval grating structure, and the -3rd or 3rd order diffraction angle of the grating is equal to the tilt angle of the large-aperture calculation holographic plate .

[0014] Further, the collimated light aiming assembly is used for coarse alignment of the to-be-tested lens, and includes a collimated light source and a two-dimensional adjusting frame. The interference alignment assembly is used for fine alignment of the to-be-tested lens, and includes two pieces of polished parallel plates, and the front surface of the parallel plate on the side facing the large-aperture plane interferometer is coated with a high-reflection film.

[0015] Further, the coarse alignment process using the collimated light aiming assembly is as follows: first, the large-aperture calculation holographic plate is moved into the detection cavity of the large-aperture plane interferometer, the collimated laser emitted by the collimated light source is incident on the large-aperture plane interferometer through the large-aperture calculation holographic plate; then, the two-dimensional attitude of the collimated light aiming assembly is adjusted, so that the collimated laser reflected by the large-aperture plane interferometer returns to the collimated light source in the original path; then, the to-be-tested lens is moved into the detection cavity of the large-aperture plane interferometer, and the two-dimensional attitude of the to-be-tested lens is adjusted, so that the collimated laser emitted by the collimated light source returns to the collimated light source in the original path after being reflected by the to-be-tested lens. The fine alignment process using the interference alignment assembly is as follows: first, the to-be-tested lens and the interference alignment assembly are moved into the detection cavity of the large-aperture plane interferometer, and the plane side of the to-be-tested lens faces the large-aperture plane interferometer; then, the two-dimensional attitude of the to-be-tested lens and the interference alignment assembly is adjusted, so that the to-be-tested lens and the interference alignment assembly can both generate interference fringes with the large-aperture plane interferometer, and the fringes are the least.

[0016] Further, the to-be-tested lens is installed on a lens tool, and the large-aperture calculation holographic plate is installed on a holographic plate tool, and L-shaped limiting blocks are arranged on the lens tool and the holographic plate tool.

[0017] A large-aperture long-focal-distance axial lens shape and property integrated detection method, including the large-aperture long-focal-distance axial lens shape and property integrated detection device; when the large-aperture long-focal-distance axial lens shape and property integrated detection device is used for shape and property integrated detection, the following steps are included: Step 1, detection cavity background wavefront calibration; Move the large-aperture standard spherical lens into the detection cavity of the large-aperture plane interferometer, and adjust the postures of the large-aperture standard spherical lens and the reference mirror of the large-aperture plane interferometer so that the reflection point of the plane standard reference surface of the large-aperture plane interferometer deviates from the field of view and the reflection point of the reference surface of the large-aperture standard spherical lens is located at the center of the field of view of the large-aperture plane interferometer; Then move the large-aperture CGH plate into the detection cavity of the large-aperture plane interferometer, adjust the axial position and two-dimensional posture of the large-aperture CGH plate, make the axial distance between the large-aperture CGH plate and the large-aperture standard spherical lens be h, and make the interference fringes of the -1 order diffraction wave in the main test area of ​​the large-aperture plane interferometer and the reference beam of the large-aperture standard spherical lens be the least, and the CGH wavefront measured by the large-aperture plane interferometer is recorded as wavefront The surface shape of the reference surface of the large-aperture standard spherical lens is measured by a large-aperture non-contact optical surface profiler and is recorded as ; then the cavity background wavefront is detected Expressed as: ; Among them, the spacing h satisfies the relationship: ; in, Indicates the fitting curvature radius of the reference surface of the large-aperture standard spherical lens. Indicates the curvature radius of the -1st order diffraction wave surface in the main test area of ​​the large-aperture CGH plate; Step 2, aligning the holographic plate; Remove the large-aperture standard spherical lens and adjust the reflection point of the plane standard reference surface of the large-aperture plane interferometer (1) to the center of the field of view; Move the large-aperture CGH plate into the detection cavity of the large-aperture planar interferometer and adjust the two-dimensional posture of the large-aperture CGH plate so that the interference fringes in the alignment area and the off-axis calibration area of ​​the large-aperture CGH plate are minimized; Step 3: Lens installation and position adjustment; Move the lens to be tested into the detection cavity of the large-aperture plane interferometer, and axially move the lens to be tested, and adjust the distance between the lens to be tested and the large-aperture CGH plate to the designed distance; Step 4, lens off-axis alignment; The lens to be tested is translated along the off-axis direction so that the interference fringes in the off-axis calibration area of ​​the large-aperture CGH plate are completely exposed. Step 5, lens posture adjustment; The collimated light aiming assembly of the attitude alignment module and the interference alignment assembly are respectively established with the reference surface of the large-aperture plane interferometer to form an orthogonal relationship of optical axes; the two-dimensional attitude of the to-be-measured lens is adjusted, so that the collimated light emitted by the collimated light aiming assembly of the attitude alignment module is reflected on the surface of the to-be-measured lens and then returns to the collimated light aiming assembly to complete the coarse alignment of the lens attitude, and the interference fringes of the interference alignment assembly are used to achieve the fine alignment of the lens attitude. Step 6, wavefront measurement; The large-aperture plane interferometer emits a parallel laser beam, and the wavefront data of the to-be-measured lens is measured by the large-aperture plane interferometer ; and the transmission wavefront of the to-be-measured lens is represented as: ; Step 7, measurement of back aperture and off-axis amount; After the transmission wavefront of the to-be-measured lens is measured , the to-be-measured lens is first moved along the axial direction, so that the defocus aberration of the transmission wavefront of the to-be-measured lens is not greater than λ / 20, and the distance D between the lens tooling and the corresponding position on the holographic plate tooling is measured by the precise distance measuring module; then the to-be-measured lens is replaced by a standard lens with a known back aperture , and the distance between the standard lens tooling and the large-aperture calculation holographic plate is measured. According to the distance D, the distance and the back aperture , the back aperture of the to-be-measured lens is calculated . According to the back aperture and the off-axis angle of the to-be-measured lens, the vertical off-axis amount of the to-be-measured lens is calculated .

[0018] Further, in step 7, the calculation formula of the back aperture is: ; The calculation formula of the vertical off-axis amount is: .

[0019] The beneficial effects of the present application are as follows: 1、In the present application, by setting the asymmetric main test area, alignment area and off-axis amount calibration area on the large-aperture calculation holographic plate, the transmission wavefront, back aperture and off-axis amount of the off-axis lens can be measured integrally, and the measurement precision of the shape and performance parameters is high.

[0020] 2、The application, by setting the posture alignment module, can conveniently and quickly adjust the posture of the to-be-measured lens, can monitor the posture of the to-be-measured lens in real time, reduces the error introduced by light path installation and adjustment, and is higher in measurement accuracy of shape and performance parameters.

[0021] 3、The application, without calibrating the curvature radius of the large-aperture computer holographic plate, adjusts the defocus aberration after measuring the transmission wave front containing the background wave front, replaces the standard lens, only needs to measure the difference of the to-be-measured lens relative to the standard lens, and finally obtains the back intercept and the off-axis amount; the whole detection process is more convenient and efficient, only the standard lens is replaced, the error introduced is smaller or no error is introduced, and the measurement accuracy of shape and performance parameters is higher.

[0022] 4、The application, in the tooling (i.e. special tooling for installing the to-be-measured lens and the large-aperture computer holographic plate) of the lens and the holographic plate, L-shaped limit blocks are arranged, and the corresponding devices are positioned and installed through the L-shaped limit blocks, so that the error introduced by device installation is reduced.

[0023] 5、The application, under the lens clamping position solidification measure, converts the distance measurement from the element to the computer hologram into the measurement of the corresponding position of the tooling; the distance from the to-be-measured lens tooling and the standard lens tooling to the computer holographic plate tooling is measured respectively, and the back intercept deviation and the off-axis amount are calculated, so that the measurement of the back intercept and the off-axis amount is more convenient and fast, and the measurement accuracy of shape and performance parameters such as the back intercept and the off-axis amount is high.

[0024] 6、The application, the optical axis of the large-aperture computer holographic plate and the optical axis of the to-be-measured lens are placed at a specific included angle, so that the non-working order stray light of the large-aperture computer holographic plate deviates from the field of view of the interferometer, the transmission wave front measurement result is not disturbed by stray light, and the reliability of the measurement result is improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the application; Figure 2 is a structural schematic diagram of the application in the calibration of the background wave front; Figure 3 is a structural schematic diagram of the large-aperture computer holographic plate in the application; Among them, A direction represents the off-axis direction of the lens; Figure 4 is a structural schematic diagram of the tooling in the application; Figure 5 is an installation schematic diagram of the precise distance measurement module in the application; Figure 6 is an installation schematic diagram of the interference alignment assembly in the application; Figure 7 is a reference surface shape measurement schematic diagram of the standard spherical lens in the application; Figure 8 Schematic diagram of test results of a test example of the present invention; Among them, A represents the background wavefront of the detection cavity, B represents the wavefront transmitted by the standard lens, C represents the wavefront transmitted by the lens 1 to be tested, D represents the wavefront transmitted by the lens 2 to be tested, and E represents the schematic diagram of the alignment state of the interferometric alignment assembly; Among them, the figure markings are: 1-large-aperture plane interferometer, 2-lens to be measured, 3-large-aperture computer-generated hologram plate, 4-posture alignment module, 5-precision ranging module, 6-large-aperture standard spherical lens, 7-interference alignment assembly, 8-L-type limit block, 9-profilometer probe, 10-reference surface, 31-substrate, 32-main test area, 33-alignment area, 34-off-axis calibration area. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0027] Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0028] Example 1 This embodiment provides a large-aperture, long-focal-distance off-axis lens shape integrated detection device for detecting shape parameters (including transmitted wavefront, back intercept, and off-axis amount) of a large-aperture, long-focal-distance off-axis lens.

[0029] like Figure 1 As shown, the detection device includes a large-aperture plane interferometer 1, a lens to be tested 2, a large-aperture computer-generated holographic plate 3, a posture alignment module 4, and a precision ranging module 5. The large-aperture plane interferometer 1, the lens to be tested 2, the large-aperture computer-generated holographic plate 3, the posture alignment module 4, and the precision ranging module 5 are all installed on an air-floating vibration isolation platform through their respective tooling (in this application, the tooling for installing the lens to be tested 2 is referred to as the lens tooling, and the tooling for installing the large-aperture computer-generated holographic plate 3 is referred to as the holographic plate tooling), which facilitates the positioning and adjustment of each component.

[0030] like Figure 4 As shown, an L-shaped limit block 8 is provided at the bottom of each tool; when installing each component, the bottom of the component is limited by the L-shaped limit block 8 to reduce the error introduced by the component installation.

[0031] The large-aperture plane interferometer 1 is used to generate and analyze interference fringes, and to calculate the transmission wavefront data of the lens 2 to be measured. During measurement, the large-aperture plane interferometer 1 emits a parallel laser beam, part of which is reflected by the reference mirror of the large-aperture plane interferometer 1 to form a reference beam, and the other part of which passes through the reference mirror of the large-aperture plane interferometer 1 to form a measurement beam. The measurement beam returns to the large-aperture plane interferometer 1 after passing through the optical path, and interferes with the reference beam to form interference fringes. By analyzing the interference fringes, the wavefront distribution can be obtained. Preferably, the measurement aperture of the large-aperture plane interferometer 1 needs to be larger than the size of the lens 2 to be measured, so that the full-aperture measurement of the lens 2 to be measured can be completed at one time. The large-aperture computer holographic plate 3 is used to compensate for aberrations of the detection optical path of the lens 2 to be measured. The large-aperture computer holographic plate 3 is made of fused quartz or microcrystalline material as a substrate, and its aperture is not less than the size of the lens 2 to be measured, like the large-aperture plane interferometer 1, so as to realize one-time full-aperture measurement. As shown in Figure 3 , the large-aperture computer holographic plate 3 is etched with a main test area 32, an alignment area 33, and an off-axis amount calibration area 34 after polishing the surface. Among them: As shown in Figure 3 , the main test area 32 is etched within the clear aperture of the large-aperture computer holographic plate 3, and is used for aberration compensation of the measurement optical path. Based on the principle of aberration compensation, the distance between the lens 2 to be measured and the large-aperture computer holographic plate 3 is set to a specific value, and the light tracing method is used for design, so as to realize zero aberration of the detection system, and shorten the detection optical path length to within 1 meter; based on the principle that the optical path lengths of each light ray within the detection aperture are equal, the -1 order of the main test area 32 diffraction wave is selected, and the graphical phase representation is: ; Among them, represents the number of Zernike terms, represents the i-th Zernike standard polynomial, represents the i-th coefficient of the Zernike standard polynomial, represents the i-th coefficient of the Zernike standard polynomial, represents the normalized radial ray coordinate, represents the angular ray coordinate.

[0032] When designing the main test area 32, the tilt angle is also introduced. For this purpose, as shown in Figure 1 , the large-aperture computer holographic plate 3 is arranged to be inclined, and the angle between the normal line of the large-aperture computer holographic plate 3 and the measurement beam is . The specific angle of the tilt angle of the large-aperture computer holographic plate 3 is different, and the final measurement effect is also different. For this purpose, in order to improve the accuracy of the shape parameter measurement, the tilt angle The best condition is met, that is, the 0th order reflected light spot of the large-aperture computer holographic plate 3 is offset from the imaging field of view of the large-aperture plane interferometer 1, and the influence of the computer holographic non-working order stray light on the measurement result can be eliminated. After the large-aperture computer holographic plate 3 is tilted, the corresponding tilt aberration is , the field of view angle of the large-aperture plane interferometer 1 , and the aperture S and the tilt aberration satisfy the relationship: After the field of view angle is obtained according to the tilt aberration, if the tilt angle is greater than the field of view angle , the non-working order stray light of the large-aperture computer holographic plate 3 can be offset from the imaging field of view of the large-aperture plane interferometer 1.

[0033] As shown in Figure 3 , the alignment area 33 is used for monitoring the test posture of the large-aperture computer holographic plate 3, and the alignment area 33 as a whole has an L-shaped structure, is etched at three corner positions outside the light transmission aperture of the large-aperture computer holographic plate 3, and the number and direction of the interference fringes can reflect the two-dimensional posture deviation of the large-aperture computer holographic plate 3. The pattern of the alignment area 33 adopts an equal-interval grating structure, and the -3rd or 3rd order diffraction angle of the grating is designed to be equal to the tilt angle of the large-aperture computer holographic plate 3. The alignment process of the alignment area 33 is as follows: the large-aperture computer holographic plate 3 is moved into the field of view range of the large-aperture plane interferometer 1, the light beam generated by the diffraction of the alignment pattern is interfered with the reference light beam of the large-aperture plane interferometer 1 to form interference fringes; the two-dimensional posture of the large-aperture computer holographic plate 3 is adjusted, and when the interference fringes are the least, it indicates that the large-aperture computer holographic plate 3 has reached the measurement condition, and the alignment is completed.

[0034] As shown in Figure 3 , the off-axis amount calibration area 34 is etched on the edge of the substrate 31 of the large-aperture computer holographic plate 3 along the off-axis direction of the lens, has a rectangular distribution, and the size of the rectangle along the off-axis direction of the lens, and is used for calibrating the off-axis amount of the to-be-measured lens 2 relative to the computer holographic plate. The pattern of the off-axis amount calibration area 34 is the same as that of the alignment area 33, and the interference fringes can be formed in the field of view of the large-aperture plane interferometer 1. When the to-be-measured lens 2 is moved into the test light path (that is, moved into the detection cavity of the large-aperture plane interferometer 1), the to-be-measured lens 2 is translated along the off-axis direction until the interference fringes of the off-axis amount calibration area 34 are completely exposed and the interference fringes of the off-axis amount calibration area 34 and the main test area 32 appear without interval, which indicates that the to-be-measured lens 2 is placed at the ideal off-axis position, that is, the off-axis amount adjustment of the to-be-measured lens 2 is ideal.

[0035] As shown in Figure 1 , Figure 6As shown, the attitude alignment module 4 includes a collimated light aiming assembly and an interference alignment assembly 7 for monitoring the attitude change of the lens under test 2 in real time, reducing the optical path installation and adjustment error. The collimated light aiming assembly is composed of a collimated light source and a two-dimensional adjustment frame, which is used for the coarse alignment of the lens under test 2. The implementation process of the coarse alignment is as follows: first, after the large-aperture computer holographic plate 3 is moved into the detection cavity of the large-aperture plane interferometer 1, the collimated laser emitted by the collimated light source is transmitted through the large-aperture computer holographic plate 3 to the reference mirror of the large-aperture plane interferometer 1; then the two-dimensional attitude of the collimated light aiming assembly is adjusted to make the collimated laser reflected by the large-aperture plane interferometer 1 return to the collimated light source along the original path, thereby establishing the orthogonal relationship between the optical axis direction of the large-aperture plane interferometer 1 (reference surface) and the collimated light aiming assembly; then the lens under test 2 is moved into the detection cavity of the large-aperture plane interferometer 1, and the two-dimensional attitude of the lens under test 2 is adjusted to make the collimated laser emitted by the collimated light source return to the collimated light source along the original path after being reflected by the lens under test 2, thereby realizing the coarse alignment of the optical axis of the large-aperture plane interferometer 1 and the lens under test 2.

[0036] The interference alignment assembly 7 is used for the fine alignment of the lens under test 2, and the interference alignment assembly 7 is fixed on the tool for mounting the lens under test 2, as shown in Figure 6 The interference alignment assembly 7 includes two polished parallel plates, and the two parallel plates are respectively installed at the diagonal positions of the lens under test 2 and have a two-dimensional attitude adjustment function. The aperture of the parallel plate is ≤100mm, the surface shape is not more than ≤1λ, the parallelism of the front and back surfaces is not more than 5", and the front surface of the parallel plate facing the large-aperture plane interferometer 1 is coated with a high-reflective film. The interference alignment assembly 7 is used for the fine alignment of the lens under test 2, and the implementation process of the fine alignment is as follows: first, the lens under test 2 and the interference alignment assembly 7 are moved into the detection cavity of the large-aperture plane interferometer 1, and the plane side of the lens under test 2 faces the large-aperture plane interferometer 1; then the two-dimensional attitude of the lens under test 2 and the interference alignment assembly 7 is adjusted to make the lens under test 2 and the interference alignment assembly 7 both generate interference fringes with the large-aperture plane interferometer 1, and the number of fringes is the least, then the optical axis direction of the lens under test 2 is consistent with the optical axis direction of the interference alignment assembly 7. When measuring the lens wavefront, the tool on which the lens under test 2 is installed is rotated to make the convex surface of the lens under test 2 face the large-aperture plane interferometer 1, the interference alignment assembly 7 is kept stationary, and the lens under test 2 is adjusted to make the interference alignment assembly 7 and the large-aperture plane interferometer 1 have the least interference fringes, which indicates that the lens has been adjusted to the ideal attitude. At this time, by monitoring the direction and number of interference fringes, the attitude change of the lens can be judged in real time.

[0037] The precise distance measuring module 5 is used for measuring the distance between the large-aperture computer holographic plate 3 and the lens under test 2 and the standard lens, and is composed of two high-precision distance sensors which are symmetrically installed on both sides of the tool for mounting the large-aperture computer holographic plate 3, as shown in Figure 5The two distance sensors respectively measure the distance from the current position to the surface of the lens 2 tool to be measured, and take the average as the distance between the large-aperture calculation holographic plate 3 and the lens 2 tool to be measured. Since the difference between the distance from the lens 2 to be measured to the large-aperture calculation holographic plate 3 and the distance from the standard lens to the large-aperture calculation holographic plate 3 is measured in the rear intercept detection method, the measurement range of the precision distance measuring module 5 only needs to exceed the distance between the lens 2 tool to be measured and the large-aperture calculation holographic plate 3 tool when the positions of the lens 2 to be measured, the standard lens, and the large-aperture calculation holographic plate 3 in the tool are fixed, and there is no need to directly measure the distance between the two polished elements, avoiding the use of a more expensive mirror distance measuring system.

[0038] When detecting, as shown in Figure 1 , the detection light path is: the large-aperture plane interferometer 1 emits a parallel laser beam, part of the parallel laser beam is reflected by the reference mirror of the large-aperture plane interferometer 1 to form a reference beam; another part of the parallel laser beam passes through the reference mirror of the large-aperture plane interferometer 1 to form a measurement beam, the measurement beam is incident on the large-aperture calculation holographic plate 3 after passing through the lens 2 to be measured, and is reflected by the large-aperture calculation holographic plate 3 to return to the large-aperture plane interferometer 1 along the original path, the measurement beam and the reference beam form interference fringes in the large-aperture plane interferometer 1, and the wavefront distribution is obtained by analyzing the interference fringes; After the wavefront distribution is measured, the lens 2 to be measured is axially moved, so that the transmitted wavefront of the lens 2 to be measured has a defocus aberration of not more than λ / 20, and the distance between the lens 2 to be measured and the large-aperture calculation holographic plate 3 is measured by the precision distance measuring module 5; the standard lens with a known rear intercept is replaced by the lens 2 to be measured, the above measurement is repeated, and the rear intercept and the off-axis amount of the lens 2 to be measured are calculated according to the distance between the lens 2 to be measured and the large-aperture calculation holographic plate 3, the distance between the standard lens and the large-aperture calculation holographic plate 3, and the rear intercept of the standard lens.

[0039] In addition, before formal detection is performed by using the detection device, the background wavefront of the detection cavity needs to be calibrated by using the large-aperture standard spherical lens 6. As shown in Figure 2 , specifically: The large-aperture standard spherical lens 6 is moved into the detection cavity of the large-aperture plane interferometer 1, the attitude of the large-aperture standard spherical lens 6 and the reference mirror of the large-aperture plane interferometer 1 is adjusted, so that the plane standard reference surface reflection point of the large-aperture plane interferometer 1 deviates from the field of view and the reflection point of the reference surface 10 of the large-aperture standard spherical lens 6 is located at the center of the field of view of the large-aperture plane interferometer 1; Then, the large-aperture calculation holographic plate 3 is moved into the detection cavity of the large-aperture plane interferometer 1, the axial position and the two-dimensional attitude of the large-aperture calculation holographic plate 3 are adjusted, so that the axial distance between the large-aperture calculation holographic plate 3 and the large-aperture standard spherical lens 6 is h, and the interference fringes of the first-order diffracted wave of the main test area of the large-aperture plane interferometer 1 and the reference beam of the large-aperture standard spherical lens 6 are the least, and the calculation holographic wavefront measured by the large-aperture plane interferometer 1 is recorded as the wavefront The surface shape of the reference surface 10 of the large-aperture standard spherical lens 6 is measured by the profilometer probe 9 and is recorded as (like Figure 7 As shown); the cavity background wavefront is detected Expressed as: ; Among them, the spacing h satisfies the relationship: ; in, represents the fitting curvature radius of the reference surface 10 of the large-aperture standard spherical lens 6, It represents the curvature radius of the first-order diffraction wave surface in the main test area 3 of the large-aperture CGH plate.

[0040] Example 2 This embodiment provides a method for integrated detection of the shape of large-aperture, long-focal-distance, off-axis lenses, which adopts the integrated detection device for the shape of large-aperture, long-focal-distance, off-axis lenses described in Example 1, and is used to detect the shape parameters (including transmitted wavefront, back intercept, and off-axis amount) of large-aperture, long-focal-distance off-axis lenses.

[0041] When using a large-aperture, long-focus-distance axis lens form-integrated detection device to perform form-integrated detection, the following steps are included: Before testing, the lens to be tested 2 and the large-aperture CGH plate 3 are mounted on their respective fixtures so that they are in close contact with the L-shaped limit blocks 8 at the bottom of the corresponding fixtures, ensuring that the components are clamped in a specific position on the fixture during each measurement, thereby reducing the error caused by component clamping.

[0042] The specific steps for testing are: Step 1, detection cavity background calibration; like Figure 2 As shown, the large-aperture standard spherical lens 6 is moved into the detection cavity of the large-aperture plane interferometer 1, and the postures of the large-aperture standard spherical lens 6, the large-aperture plane interferometer 1, and the reference mirror of the large-aperture plane interferometer 1 are adjusted so that the reflection point of the plane standard reference surface of the large-aperture plane interferometer 1 deviates from the field of view and the reflection point of the reference surface 10 of the large-aperture standard spherical lens 6 is located at the center of the field of view of the large-aperture plane interferometer 1; Then, the large-aperture CGH plate 3 is moved into the detection cavity of the large-aperture plane interferometer 1, and the axial position and two-dimensional posture of the large-aperture CGH plate 3 are adjusted so that the axial distance between the large-aperture CGH plate 3 and the large-aperture standard spherical lens 6 is h, and the interference fringes between the -1st order diffraction wave in the main test area of ​​the large-aperture plane interferometer 1 and the reference beam of the large-aperture standard spherical lens 6 are the least. The CGH wavefront measured by the large-aperture plane interferometer 1 is recorded as wavefront The surface shape of the reference surface 10 of the large-aperture standard spherical lens 6 is measured by the profilometer probe 9 and is recorded as As shown in Figure 7 the cavity background wavefront is expressed as: ; wherein the interval h satisfies the relationship: ; wherein, represents the fitting radius of curvature of the reference surface 10 of the large-aperture standard spherical lens 6, represents the radius of curvature of the -1 order diffracted wave surface of the main test area of the large-aperture computer holographic plate 3.

[0043] Step 2, holographic plate alignment; Remove the large-aperture standard spherical lens 6, and adjust the reflection point of the reference surface 10 of the large-aperture standard spherical lens 6 to the center of the field of view; Move the large-aperture computer holographic plate 3 into the detection cavity of the large-aperture plane interferometer 1, and adjust the two-dimensional pose of the large-aperture computer holographic plate 3 to minimize the interference fringes of the alignment area 33 and the off-axis amount calibration area 34 of the large-aperture computer holographic plate 3.

[0044] Step 3, lens installation and position adjustment; Move the lens to be tested 2 into the detection cavity of the large-aperture plane interferometer 1, and axially move the lens to be tested 2 to adjust the interval between the lens to be tested 2 and the large-aperture computer holographic plate 3 to the design distance (which is a distance known before detection, i.e., a preset value).

[0045] Step 4, lens off-axis alignment; Translate the lens to be tested 2 in the off-axis direction to make the off-axis amount calibration area of the large-aperture computer holographic plate 3 interfere with the fringes just completely out.

[0046] Step 5, lens pose adjustment; The collimated light aiming assembly and the interference aiming assembly of the pose alignment module 4 respectively establish an optical axis orthogonal relationship with the reference surface of the large-aperture plane interferometer 1; adjust the two-dimensional pose of the lens to be tested 2, so that the collimated light emitted by the collimated light aiming assembly of the pose alignment module 4 returns to the collimated light aiming assembly after being reflected by the surface of the lens to be tested 2 to complete the coarse alignment of the lens pose, and the interference fringes of the interference aiming assembly are minimized to achieve fine alignment of the lens pose.

[0047] When using the pose alignment module 4 to align the pose alignment module 4, it includes coarse alignment and fine alignment; wherein the coarse alignment is realized by the collimated light aiming assembly, and the fine alignment is realized by the interference aiming assembly.

[0048] The implementation process of the coarse alignment by the collimated light aiming assembly is as follows: first, the large-aperture computer holographic plate 3 is moved into the detection cavity of the large-aperture plane interferometer 1, collimated laser emitted by the collimated light source is transmitted through the large-aperture computer holographic plate 3 and is incident to the reference mirror of the large-aperture plane interferometer 1; then, the two-dimensional attitude of the collimated light aiming assembly is adjusted, so that the collimated laser reflected by the large-aperture plane interferometer 1 returns to the collimated light source along the original path, thereby establishing the orthogonal relationship between the optical axis direction of the large-aperture plane interferometer 1 (reference surface) and the collimated light aiming assembly; then, the lens to be measured 2 is moved into the detection cavity of the large-aperture plane interferometer 1, and the two-dimensional attitude of the lens to be measured 2 is adjusted, so that the collimated laser emitted by the collimated light source returns to the collimated light source along the original path after being reflected by the lens to be measured 2, thereby realizing the coarse alignment of the optical axis of the large-aperture plane interferometer 1 and the lens to be measured 2.

[0049] The implementation process of the fine alignment by the interference alignment assembly 7 is as follows: first, the lens to be measured 2 and the interference alignment assembly 7 are moved into the detection cavity of the large-aperture plane interferometer 1, and the plane side of the lens to be measured 2 faces the large-aperture plane interferometer 1; then, the two-dimensional attitude of the lens to be measured 2 and the interference alignment assembly 7 is adjusted, so that the lens to be measured 2 and the interference alignment assembly 7 can both generate interference fringes with the large-aperture plane interferometer 1 and the number of fringes is the least, and then the optical axis direction of the lens to be measured 2 is consistent with the optical axis direction of the interference alignment assembly 7. When measuring the wavefront of the lens, the tool on which the lens to be measured 2 is mounted is rotated, so that the convex surface of the lens to be measured 2 faces the large-aperture plane interferometer 1, the interference alignment assembly 7 is kept stationary, and the lens to be measured 2 is adjusted so that the interference alignment assembly 7 and the large-aperture plane interferometer 1 generate the least interference fringes, which indicates that the lens has been adjusted to the ideal attitude. At this time, the change of the attitude of the lens can be judged in real time by monitoring the direction and number of the interference fringes.

[0050] Step 6, wavefront measurement; The large-aperture plane interferometer 1 emits a parallel laser beam, and the wavefront data of the lens to be measured 2 is measured by the large-aperture plane interferometer 1 ; the transmission wavefront of the lens to be measured 2 is represented as: .

[0051] Step 7, measurement of back intercept and off-axis amount; After the transmission wavefront of the lens to be measured 2 is measured , the lens to be measured 2 is first moved along the axial direction, so that the off-focus aberration of the lens to be measured 2 is not greater than λ / 20; the distance between the large-aperture computer holographic plate 3 tool and the surface of the lens to be measured 2 tool is measured by two distance sensors of the precision distance measuring module 5 、 , and then the distance D is calculated by the formula .

[0052] Then, the known intercept The standard lens replaces the to-be-tested lens 2, and the distance between the standard lens and the large-aperture plane interferometer 1 is measured .

[0053] According to the distance D, the distance and the intercept , the back intercept of the to-be-tested lens 2 is calculated ; the calculation formula of the back intercept is: ; According to the back intercept and the off-axis angle of the to-be-tested lens 2 , the vertical off-axis amount of the to-be-tested lens 2 is calculated ; the calculation formula of the vertical off-axis amount is: .

[0054] Test example In this test example, the detection device described in Example 1 and the detection method described in Example 2 are used to perform detection tests on the shape and performance parameters of a standard lens and two pieces of 400nm-aperture off-axis plano-convex lenses. Specifically: I. Test instruments: 1. 600mm plane interferometer; 2. Standard lens (back intercept 12709.8mm, vertical off-axis amount 498.54mm, off-axis angle 2.248°); 3. 410mm-aperture calculation holographic plate; 4. 400nm-aperture off-axis plano-convex lens 5. Precise distance measuring module (distance measuring accuracy 0.1mm, range 0~500mm); 6. Attitude alignment module.

[0055] The rest can refer to Example 1.

[0056] II. Test steps: The detection method of Example 2 is used to detect the standard lens and two pieces of 400nm-aperture off-axis plano-convex lenses.

[0057] III. Test results: The shape and performance parameter measurement results are shown in Table 1:

[0058] The images obtained in the test are shown in Figure 8 .

[0059] IV. Result analysis: The shape and performance parameters of two lenses are measured by the experimental device, and the wavefront distribution is normal. When the defocus aberration is controlled within λ / 20, the relative back focal length deviation of the two lenses is-0.19 mm and-4.06 mm, respectively. Considering the factors of clamping, repeatability, distance measurement error and defocus error, the back focal length error is about 0.8 mm, and the relative accuracy of back focal length and off-axis distance is about 0.007%. The device and method can also be used for the consistency measurement of shape and performance parameters of similar batch lenses.

Claims

1. A large-aperture, long-focus-distance, axial lens shape integrated detection device, characterized by: It includes a large-aperture plane interferometer (1), a lens to be measured (2), a large-aperture computer-generated hologram plate (3), a posture alignment module (4), and a precision distance measurement module (5); The surface of the large-aperture computer-generated holographic plate (3) is etched with a main test area (32), an alignment area (33), and an off-axis calibration area (34); the main test area (32) is located within the light-clearing aperture of the large-aperture computer-generated holographic plate (3) and is used to compensate for the aberration of the measurement optical path; the alignment area (33) is located at three corner positions outside the light-clearing aperture of the large-aperture computer-generated holographic plate (3) and is used to monitor the test posture of the large-aperture computer-generated holographic plate (3); the off-axis calibration area (34) is rectangular and is located at the edge of the substrate (31) of the large-aperture computer-generated holographic plate (3) along the off-axis direction of the lens and is used to calibrate the off-axis amount of the lens (2) to be tested; The posture alignment module (4) includes a collimated light aiming component and an interference alignment component (7); during posture alignment, the posture of the lens to be measured (2) is adjusted so that the collimated light emitted by the collimated light aiming component is reflected by the surface of the lens to be measured (2) and then returned to the collimated light aiming component, thereby completing the rough alignment of the lens posture, and then the posture of the lens to be measured (2) is finely aligned by the interference fringes of the interference alignment component (7); A precision distance measurement module (5) is used to measure the distance between the lens to be measured (2) and the large-aperture computer-generated holographic plate (3); The measuring optical path is as follows: a large-aperture plane interferometer (1) emits a parallel laser beam, part of which is reflected by a reference mirror of the large-aperture plane interferometer (1) to form a reference beam; another part of the parallel laser beam passes through the reference mirror of the large-aperture plane interferometer (1) to form a measuring beam, the measuring beam is incident on a large-aperture computerized holographic plate (3) after passing through a lens to be measured (2), and is reflected by the large-aperture computerized holographic plate (3) and then returns to the large-aperture plane interferometer (1) along the original path, the measuring beam and the reference beam form interference fringes, and the interference fringes are analyzed to obtain a wavefront analysis. The lens to be tested (2) is then axially moved so that the transmission wavefront defocus aberration of the lens to be tested (2) is not greater than λ / 20, and the spacing between the lens to be tested (2) and the large-aperture computational holographic plate (3) is measured using a precision distance measurement module (5); a standard lens with a known back focus is substituted for the lens to be tested (2), and the above measurement is repeated. The back focus and off-axis amount of the lens to be tested (2) are calculated based on the spacing between the lens to be tested (2) and the large-aperture computational holographic plate (3), the spacing between the standard lens and the large-aperture computational holographic plate (3), and the back focus of the standard lens.

2. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 1, characterized in that: The material of the substrate (31) of the large-aperture computer-generated holographic plate (3) is fused quartz or microcrystalline material, and the aperture of the large-aperture computer-generated holographic plate (3) is greater than or equal to the aperture of the lens (2) to be measured.

3. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 1, characterized in that: The large-aperture computational holographic plate (3) is tilted, and the tilt angle between the normal line of the large-aperture computational holographic plate (3) and the optical axis of the measurement beam is Requirements: The large-aperture computer-generated holographic plate (3) is tilted so that the 0th-order reflected light spot of the large-aperture computer-generated holographic plate (3) deviates from the imaging field of view of the large-aperture plane interferometer (1).

4. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 3, characterized in that: The diffraction wave of the main test area (32) is selected at level -1, and the graphic phase representation is: ； in, Represents the number of Zernike terms, represents the i-th Zernike standard polynomial, represents the Zernike standard polynomial Term coefficient, represents the normalized radial ray coordinates, Represents the angular ray coordinates.

5. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 3, characterized in that: The alignment area (33) adopts an equally spaced grating structure, and the -3rd or 3rd order diffraction angle of the grating is equal to the tilt angle of the large-aperture computer-generated holographic plate (3). .

6. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 1, characterized in that: The collimated light aiming assembly is used for coarse alignment of a lens to be measured (2), and comprises a collimated light source and a two-dimensional adjustment frame; The interference alignment assembly (7) includes two polished parallel plates, and the front surface of the parallel plate facing the large-aperture plane interferometer (1) is coated with a high-reflection film. It is assembled on the tooling of the lens to be tested (2) and can move synchronously with the lens to be tested for precise posture alignment of the lens to be tested (2).

7. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 6, characterized in that: The process of coarse alignment using the collimated light aiming assembly is as follows: first, a large-aperture computer-generated holographic plate (3) is moved into the detection cavity of the large-aperture plane interferometer (1), and the collimated laser light emitted by the collimated light source is incident on the large-aperture plane interferometer (1) through the large-aperture computer-generated holographic plate (3); then, by adjusting the two-dimensional posture of the collimated light aiming assembly, the collimated laser light reflected by the large-aperture plane interferometer (1) is returned to the collimated light source along the original path; then, the lens to be measured (2) is moved into the detection cavity of the large-aperture plane interferometer (1), and the two-dimensional posture of the lens to be measured (2) is adjusted, so that the collimated laser light emitted by the collimated light source is reflected by the lens to be measured (2) and returned to the collimated light source along the original path; The process of fine alignment using the interference alignment assembly (7) is as follows: first, the lens to be measured (2) and the interference alignment assembly (7) are moved into the detection cavity of the large-aperture plane interferometer (1), with the plane side of the lens to be measured (2) facing the large-aperture plane interferometer (1); then, the two-dimensional postures of the lens to be measured (2) and the interference alignment assembly (7) are adjusted so that both the lens to be measured (2) and the interference alignment assembly (7) can generate interference fringes with the large-aperture plane interferometer (1), and the fringes are minimal.

8. The large-aperture, long-focal-distance, axial lens shape integrated detection device according to claim 1, characterized in that: The lens to be tested (2) is mounted on a lens fixture, and the large-aperture computerized holographic plate (3) is mounted on a holographic plate fixture. L-shaped limit blocks (8) are provided on the surfaces of the lens fixture and the holographic plate fixture.

9. A method for integrated detection of the shape of a large-aperture, long-focus-distance axial lens, characterized in that: The invention comprises the large-aperture, long-focal-distance, axis-lens form-integrated detection device according to any one of claims 1 to 8; when using the large-aperture, long-focal-distance, axis-lens form-integrated detection device to perform form-integrated detection, the invention comprises the following steps: Step 1, detection cavity background calibration; Move the large-aperture standard spherical lens (6) into the detection cavity of the large-aperture plane interferometer (1), and adjust the postures of the large-aperture standard spherical lens (6) and the reference mirror of the large-aperture plane interferometer (1) so that the reflection point of the plane standard reference surface of the large-aperture plane interferometer (1) deviates from the field of view and the reflection point of the reference surface (10) of the large-aperture standard spherical lens (6) is located at the center of the field of view of the large-aperture plane interferometer (1); Then, the large-aperture CGH plate (3) is moved into the detection cavity of the large-aperture plane interferometer (1), and the axial position and two-dimensional posture of the large-aperture CGH plate (3) are adjusted so that the axial spacing between the large-aperture CGH plate (3) and the large-aperture standard spherical lens (6) is h, and the interference fringes between the -1 order diffraction wave of the main test area of ​​the large-aperture plane interferometer (1) and the reference beam of the large-aperture standard spherical lens (6) are the least. The CGH wavefront measured by the large-aperture plane interferometer (1) is recorded as wavefront The surface shape of the reference surface (10) of the large-aperture standard spherical lens (6) is measured by the profilometer probe (9) and is recorded as ; then the cavity background wavefront is detected Expressed as: ； Among them, the spacing h satisfies the relationship: ； in, represents the fitted curvature radius of the reference surface (10) of the large-aperture standard spherical lens (6), represents the curvature radius of the first-order diffraction wave surface in the main test area of ​​the large-aperture CGH plate (3); Step 2, aligning the holographic plate; Remove the large-aperture standard spherical lens (6) and adjust the reflection point of the plane standard reference surface of the large-aperture plane interferometer (1) to the center of the field of view; The large-aperture CGH plate (3) is moved into the detection cavity of the large-aperture plane interferometer (1), and the two-dimensional posture of the large-aperture CGH plate (3) is adjusted so that the interference fringes in the alignment area (33) and the off-axis calibration area (34) of the large-aperture CGH plate (3) are minimized; Step 3: Lens installation and position adjustment; The lens to be tested (2) is moved into the detection cavity of the large-aperture plane interferometer (1), and the lens to be tested (2) is moved axially, and the distance between the lens to be tested (2) and the large-aperture computer-generated holographic plate (3) is adjusted to a designed distance; Step 4, lens off-axis alignment; The lens to be tested (2) is translated along the off-axis direction so that the interference fringes in the off-axis calibration area of ​​the large-aperture computer-generated hologram plate (3) are completely leaked out; Step 5, lens posture adjustment; The collimated light aiming component and the interference alignment component of the attitude alignment module (4) are respectively used to establish an optical axis orthogonal relationship with the reference surface of the large-aperture plane interferometer (1); the two-dimensional attitude of the lens to be measured (2) is adjusted so that the collimated light emitted by the collimated light aiming component of the attitude alignment module (4) is reflected by the surface of the lens to be measured (2) and then returned to the collimated light aiming component to complete the rough alignment of the lens attitude, and the interference fringes of the interference alignment component are minimized to achieve the fine alignment of the lens attitude; Step 6, wavefront measurement; The large-aperture plane interferometer (1) emits a parallel laser beam, and the wavefront data of the lens to be measured (2) is measured by the large-aperture plane interferometer (1). ; Then the transmitted wavefront of the lens (2) to be tested is Expressed as: ； Step 7, back intercept and off-axis measurement; Measure the transmitted wavefront of the lens (2) to be tested Then, the lens to be tested (2) is first moved axially so that the defocus aberration of the transmitted wavefront of the lens to be tested (2) is not greater than λ / 20, and the distance D between the lens fixture and the corresponding position on the holographic plate fixture is measured by the precision distance measurement module (5); then, the known intercept is used to measure the distance D between the lens fixture and the corresponding position on the holographic plate fixture. The standard lens is used to replace the lens to be tested (2), and the distance between the standard lens fixture and the large-aperture CGH plate (3) is measured. ; According to distance D, distance and intercept Calculate the back focus of the lens to be tested (2) ; According to the back intercept , the off-axis angle of the lens to be tested (2) Calculate the vertical off-axis value of the lens (2) to be tested .

10. The method for integrated detection of the shape of a large-aperture, long-focus-distance axial lens according to claim 9, characterized in that: In step 7, the back intercept The calculation formula is: ； Vertical off-axis The calculation formula is: 。

Images