Off-axis concave parabolic reflector detection system and method based on aberration-free point method

Abstract

The present invention relates to the field of reflector detection technology, and specifically discloses a detection system and method for an off-axis concave parabolic reflector based on an aberration-free point method. In the detection system: a laser on one side of a laser level is projected onto a reference wall to obtain a reference light beam as a reference datum; the laser on the other side of the laser level is respectively reflected to the reference wall by an interferometer, an auxiliary plane reflector assembly, and a plane reflector arranged on an off-axis concave parabolic reflector assembly, and the relative positions of the various components are adjusted so that the light beam reflected to the reference wall overlaps with the reference light beam. The present invention can quickly establish a measurement method for a spatial reference to improve detection efficiency and detection accuracy; after the present invention introduces a laser level as a collimated laser, it is easy to establish a reference datum; through the ingenious arrangement of the plane reflector, the present invention can intuitively reflect the reference relationship between various components, thereby making corrections.

Description

Technical Field

[0001] The invention relates to the technical field of reflector detection, and in particular to a detection system and method for an off-axis concave parabolic reflector based on an aberration-free point method. Background Art

[0002] In optical design, spherical elements have the ability to correct aberrations and are easy to process and manufacture. They are usually used in optical systems such as lenses, telescopes, and lasers. With the continuous improvement of the imaging quality requirements of optical systems, although the correction of system aberrations can be completed by increasing the number of lenses, this approach will increase the volume and mass of the system, which is not in line with the development trend of lightweight and miniaturization.

[0003] Aspheric optical elements can effectively correct aberrations and improve imaging quality due to the change in their curvature, while meeting the requirements for the lightweight development of optical systems. They have a wider range of application scenarios in the fields of aerospace, medical, and high-power lasers. In addition to the above advantages, off-axis aspheric surfaces provide more freedom for aberration correction in the design of optical systems because their geometric axes do not coincide with the optical axes. Although off-axis aspheric surfaces help solve the problem of reduced imaging quality due to obstruction of the center of the component, the misalignment of the geometric axis and the optical axis increases the difficulty of detecting the surface shape of the component. For the detection of off-axis aspheric surfaces, the most commonly used methods are interferometry and profilometry. The advantages of interferometric detection are high resolution, high precision, and high sensitivity. With the development of computer-generated holographic compensator technology, the measurement accuracy and efficiency of off-axis aspheric surfaces are relatively high. However, its detection accuracy is easily affected by the environment, and the requirements for the detection environment are high, while increasing the detection cost. For the profilometer, although no compensation device is required when measuring off-axis aspheric surfaces, the measurement speed is slow and the measurement accuracy is affected by the motion mechanism, which makes it difficult to obtain high-precision test results. At the same time, the contact between the probe and the surface of the measured component will damage the surface of the component. In recent years, manufacturing technology has developed rapidly, but the corresponding measurement capabilities sometimes cannot keep up with manufacturing capabilities. Therefore, the existing measurement methods will have certain limitations on the manufacturing of off-axis aspheric surfaces.

[0004] In the process of building the optical path, it is not easy to establish a good spatial position relationship between the interferometer and the reflector to be measured, which will make it difficult to find the image point during the measurement process. Even if the image point is found, it still takes a lot of time to fine-tune the tilt and eccentricity between various components in order to measure a more ideal surface value. Therefore, those skilled in the art urgently need a measurement method that can quickly establish a spatial reference to improve detection efficiency and detection accuracy. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects existing in the above-mentioned prior art, thereby providing a system and method for detecting an off-axis concave parabolic reflector based on the aberration-free point method.

[0006] An off-axis concave parabolic reflector detection system based on an aberration-free point method includes: an interferometer reference component, an auxiliary plane reflector reference component, and an off-axis concave parabolic reflector reference component;

[0007] The reference datum of the detection system is the reference light formed when the laser on one side of the laser level is projected onto the reference wall;

[0008] The interferometer reference component is composed of a pair of plane reflectors arranged orthogonally in the direction of the laser on the other side of the laser level and the interferometer lens and a reference wall surface connected in optical paths in sequence, so that the light reflected by the plane reflector to the reference wall surface coincides with the reference light;

[0009] The auxiliary plane reflector reference component is formed by optically connecting the laser on the other side of the laser level and the reflective surface of the auxiliary plane reflector of the auxiliary plane reflector assembly and the reference wall in sequence, so that the light reflected by the auxiliary plane reflector to the reference wall coincides with the reference light;

[0010] The off-axis concave parabolic reflector reference component is formed by optically connecting the laser on the other side of the laser level and a pair of orthogonally arranged plane reflectors on the fixture of the off-axis concave parabolic reflector assembly and the reference wall in sequence, so that the light reflected by the plane reflector to the reference wall coincides with the reference light;

[0011] The interferometer, the auxiliary plane reflector, the off-axis concave parabola reflector of the off-axis concave parabola reflector assembly and the reference wall are all in parallel relative positions in the reference state;

[0012] The focus of the off-axis concave parabolic reflector is adjusted to coincide with the focus of the interferometer. The detection beam emitted by the interferometer is incident on the reflective surface of the off-axis concave parabolic reflector, reflected to the auxiliary plane reflector, and finally returns to the interferometer along the original path to form interference fringes.

[0013] The interferometer, the auxiliary plane reflector assembly, the off-axis concave parabolic reflector assembly and the laser level are respectively installed on the air-floating optical platform through a six-dimensional adjustment device.

[0014] Preferably, the auxiliary plane reflector assembly is composed of an auxiliary plane reflector and an adapted plane reflector mounting frame;

[0015] The auxiliary plane reflector is mounted on the corresponding six-dimensional adjustment device through a plane reflector mounting frame.

[0016] Preferably, the off-axis concave parabolic reflector assembly is composed of a fixture frame, a reflector chamber and an off-axis concave parabolic reflector;

[0017] The off-axis concave parabolic reflector is installed in a reflector chamber, the reflector chamber is installed on a tooling frame, and the tooling frame is installed on a corresponding six-dimensional adjustment device.

[0018] Preferred:

[0019] A circular hole is provided in the middle of the auxiliary plane reflector;

[0020] The reflecting surface of the auxiliary plane reflecting mirror faces away from the interferometer lens;

[0021] The reflecting surface of the auxiliary plane reflector is close to the intersection of the focus of the off-axis concave parabolic reflector and the focus of the interferometer;

[0022] The optical axis of the auxiliary plane mirror coincides with the optical axis of the interferometer.

[0023] Preferably, a pair of orthogonally arranged plane reflectors on the interferometer comprises: a first reflector and a second reflector;

[0024] A first reflector and a second reflector are arranged in the direction of the interferometer parallel to the interferometer lens, and the first reflector is arranged orthogonally to the second reflector.

[0025] Preferred:

[0026] The center of the off-axis concave parabolic reflector is aligned with the optical axis position of the interferometer;

[0027] The reflecting surface of the off-axis concave parabolic reflector faces the interferometer lens side;

[0028] The reflecting surfaces of a pair of orthogonally arranged plane reflecting mirrors on the fixture frame face away from the interferometer lens direction.

[0029] Preferably, a pair of orthogonally arranged plane reflectors on the fixture frame include: a third reflector and a fourth reflector;

[0030] The tooling frame is provided with grooves for placing the third reflector and the fourth reflector, and the groove for placing the third reflector and the groove for placing the fourth reflector are arranged orthogonally;

[0031] Each groove is provided with axially evenly distributed glue injection grooves on its circumference.

[0032] The off-axis concave parabolic reflector detection method based on the aberration-free point method is implemented by using the off-axis concave parabolic reflector detection system, including the following steps:

[0033] S1. Establish a detection benchmark: install a laser level on the air-floating optical platform, and install a reference wall on one side of the air-floating optical platform; obtain a reference light as a reference based on the laser on one side of the laser level and the reference wall;

[0034] S2. Perform a reference indication on the interferometer installed on the air-floating optical platform: Use the laser on the other side of the laser level to adjust the reference of the interferometer so that the first reflected light reflected by a pair of orthogonal plane mirrors in the direction of the interferometer lens to the reference wall coincides with the reference light, completing the initial reference adjustment of the interferometer;

[0035] S3. Perform a reference indication on the auxiliary plane reflector mounted on the air-floating optical platform: Use the laser on the other side of the laser level to adjust the reference of the auxiliary plane reflector so that the second reflected light reflected by the auxiliary plane reflector to the reference wall coincides with the reference light, completing the initial reference adjustment of the auxiliary plane reflector;

[0036] S4. Perform a reference indication on the off-axis concave parabolic reflector mounted on the air-floating optical platform: Use the laser on the other side of the laser level to perform a reference adjustment on the off-axis concave parabolic reflector so that the third reflected light reflected by a pair of orthogonally arranged plane reflectors on the fixture frame to the reference wall coincides with the reference light, completing the initial reference adjustment of the off-axis concave parabolic reflector;

[0037] S5. According to the optical design results of the off-axis concave parabolic reflector, by adjusting the displacement of the corresponding six-dimensional adjustment device, according to the off-axis amount and the displacement in the direction of the optical axis, the focus of the off-axis concave parabolic reflector and the focus of the interferometer are adjusted to coincide, so that the measuring light beam emitted by the interferometer is incident on the reflecting surface of the off-axis concave parabolic reflector, and reflected to the auxiliary plane reflector, and finally returns to the interferometer along the original path to form interference fringes to complete the detection.

[0038] Preferably, the method further comprises step S6:

[0039] The six-dimensional adjustment device corresponding to the off-axis concave parabolic reflector is adjusted to adjust the defocus and coma terms of the Zernike coefficient to less than 0.003 wavelength.

[0040] The technical solution of the present invention has the following advantages:

[0041] 1. The present invention proposes an off-axis concave parabolic reflector detection system and detection method based on the aberration-free point method, which improves the detection efficiency and detection accuracy, and the detection method is simple and easy to operate.

[0042] 2. The present invention describes an off-axis concave parabolic reflector detection system based on the aberration-free point method, which introduces a laser level as a collimated laser. After the preliminary establishment of the benchmark with the interferometer, there is no need to adjust the laser level, which improves the stability of the benchmark transmission and makes it easy to establish the reference benchmark for each component.

[0043] 3. The present invention introduces a clever arrangement of two pairs of orthogonally arranged plane reflectors to transfer the reference of each component to the plane reflector, so that the present invention can intuitively reflect the reference relationship between each component and make corrections.

[0044] 4. The present invention describes a method for detecting off-axis concave parabolic reflectors based on the aberration-free point method. After the collimated laser is reflected by the small plane reflector to the reference wall, the status of existing components can be intuitively observed, and the position of the components can be adjusted to make them coincide with the reference light, thereby greatly improving the detection rate and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A top view of the off-axis concave parabolic reflector detection system of the present invention;

[0047] Figure 2 It is a front view of the off-axis concave parabolic reflector detection system of the present invention;

[0048] Figure 3 A schematic diagram of components when establishing a reference for the interferometer of the present invention;

[0049] Figure 4 A schematic diagram of light on a reference wall when establishing a reference for the interferometer of the present invention;

[0050] Figure 5 A schematic diagram of components when establishing a reference for the auxiliary plane reflector of the present invention;

[0051] Figure 6 A schematic diagram of light on a reference wall when establishing a reference for the auxiliary plane reflector of the present invention;

[0052] Figure 7 It is a schematic diagram of an off-axis concave parabolic reflector assembly of the present invention;

[0053] Figure 8 A schematic diagram of the components when establishing a reference for the off-axis concave parabolic reflector of the present invention;

[0054] Fig. 9 A schematic diagram of light on a reference wall when establishing a reference for the off-axis concave parabolic reflector of the present invention.

[0055] Description of reference numerals:

[0056] 1-air-floating optical platform; 201-first six-dimensional adjustment platform; 202-second six-dimensional adjustment platform; 203-third six-dimensional adjustment platform; 204-fourth six-dimensional adjustment platform; 3-interferometer; 4-auxiliary plane reflector; 5-plane reflector mounting frame; 6-tooling frame; 7-reflector chamber; 8-off-axis concave parabolic reflector; 9-laser level; 10-reference wall;

[0057] 301-first reflector; 302-second reflector; 601-third reflector; 602-fourth reflector;

[0058] 1001 - reference light; 1002 - first reflected light; 1003 - second reflected light; 1004 - third reflected light. DETAILED DESCRIPTION

[0059] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0061] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0063] Example 1

[0064] like Figure 1-9The embodiment shown discloses a detection system for an off-axis concave parabolic reflector based on an aberration-free point method, comprising: an interferometer reference component, an auxiliary plane reflector reference component, and an off-axis concave parabolic reflector reference component;

[0065] The reference datum of the detection system is the reference light 1001 formed by the laser from one side of the laser level 9 projecting onto the reference wall 10;

[0066] The interferometer reference component is composed of a pair of plane reflectors orthogonally arranged in the direction of the laser on the other side of the laser level 9 and the lens of the interferometer 3 and a reference wall 10 connected in sequence by optical paths, so that the light reflected by the plane reflector to the reference wall 10 coincides with the reference light 1001;

[0067] The auxiliary plane reflector reference component is formed by optically connecting the laser on the other side of the laser level 9 and the reflective surface of the auxiliary plane reflector 4 of the auxiliary plane reflector assembly and the reference wall 10 in sequence, so that the light reflected by the auxiliary plane reflector 4 to the reference wall 10 coincides with the reference light 1001;

[0068] The off-axis concave parabolic reflector reference component is composed of a laser on the other side of the laser level 9 and a pair of orthogonally arranged plane reflectors on the fixture frame 6 of the off-axis concave parabolic reflector assembly and a reference wall 10 connected in sequence by optical paths, so that the light reflected by the plane reflector to the reference wall 10 coincides with the reference light 1001;

[0069] The interferometer 3, the auxiliary plane reflector 4, the off-axis concave parabola reflector 8 of the off-axis concave parabola reflector assembly and the reference wall 10 in the reference state are all in parallel relative positions;

[0070] Adjust the focus of the off-axis concave parabolic reflector 8 to coincide with the focus of the interferometer 3, so that the detection beam emitted by the interferometer 3 is incident on the reflection surface of the off-axis concave parabolic reflector 8, reflected to the auxiliary plane reflector 4, and finally returns to the interferometer 3 along the original path to form interference fringes;

[0071] The interferometer 3, the auxiliary plane reflector assembly, the off-axis concave parabolic reflector assembly and the laser level 9 are respectively installed on the air-floating optical platform 1 through a six-dimensional adjustment device.

[0072] Specifically:

[0073] like Figure 1 , 2 , 3, 5 and 8 show a six-dimensional adjustment device comprising:

[0074] The first six-dimensional adjustment platform 201 is correspondingly connected to the interferometer 3, so that the interferometer 3 is installed on the air-floating optical platform;

[0075] The second six-dimensional adjustment platform 202 is correspondingly connected to the auxiliary plane reflector assembly, so that the auxiliary plane reflector assembly is installed on the air-floating optical platform;

[0076] The third six-dimensional adjustment platform 203 is correspondingly connected to the off-axis concave parabolic reflector assembly, so that the off-axis concave parabolic reflector assembly is installed on the air-floating optical platform;

[0077] The fourth six-dimensional adjustment platform 205 is correspondingly connected to the laser level 9 so that the laser level 9 is installed on the air-floating optical platform;

[0078] like Figure 1 , 2 , 5 and 8 show that in this embodiment, the auxiliary plane reflector assembly is composed of an auxiliary plane reflector 4 and an adapted plane reflector mounting frame 5;

[0079] The auxiliary plane reflector 4 is mounted on the corresponding second six-dimensional adjustment platform 202 through the plane reflector mounting frame 5 .

[0080] like Figure 1-2 7-8 In this embodiment, the off-axis concave parabolic reflector assembly is composed of a fixture frame 6, a reflector chamber 7 and an off-axis concave parabolic reflector 8;

[0081] The off-axis concave parabolic reflector 8 is installed in the reflector chamber 7 , the reflector chamber 7 is installed on the tooling frame 6 , and the tooling frame 6 is installed on the corresponding third six-dimensional adjustment platform 203 .

[0082] like Figure 1 , 2 As shown in Figure 5, in this embodiment, based on the interferometer 3 reference component, the reference component of the auxiliary plane reflector 4 also includes:

[0083] A circular hole is provided in the middle of the auxiliary plane reflector 4;

[0084] The reflecting surface of the auxiliary plane reflector 4 faces away from the lens direction of the interferometer 3;

[0085] The reflecting surface of the auxiliary plane reflector 4 is close to the intersection position of the focus of the off-axis concave parabolic reflector 8 and the focus of the interferometer 3;

[0086] The optical axis of the auxiliary plane reflector 4 coincides with the optical axis of the interferometer 3 .

[0087] like Figure 2 In this embodiment, a pair of orthogonally arranged plane reflectors on the interferometer 3 includes: a first reflector 301 and a second reflector 302. Specifically:

[0088] The first reflector 301 and the second reflector 302 are arranged parallel to the interferometer lens in the interferometer 3, and the first reflector 301 and the second reflector 302 are arranged orthogonally. The first reflector 301 and the second reflector 302 have the same size and components and are adapted to the size of the interferometer 3.

[0089] In this embodiment, on the basis of the interferometer 3 and the auxiliary plane reflector 4 being in the reference component, the off-axis concave parabolic reflector 8 reference component also includes:

[0090] The center of the off-axis concave parabolic reflector 8 is aligned with the optical axis position of the interferometer 3;

[0091] The reflecting surface of the off-axis concave parabolic reflector 8 faces the lens side of the interferometer 3;

[0092] The reflecting surfaces of a pair of orthogonally arranged plane reflectors on the fixture frame 6 face away from the lens direction of the interferometer 3 .

[0093] like Figure 7 In this embodiment, a pair of orthogonally arranged plane reflectors on the fixture frame 6 include: a third reflector 601 and a fourth reflector 602;

[0094] The fixture frame 6 is provided with grooves for placing the third reflector 601 and the fourth reflector 602, and the groove for placing the third reflector 601 and the groove for placing the fourth reflector 602 are arranged orthogonally; the third reflector 601 and the fourth reflector 602 have the same size and components and are adapted to the fixture frame 6;

[0095] Each groove is provided with axially uniformly distributed glue injection grooves on its circumference. After the third reflector 601 and the fourth reflector 602 are installed in the grooves of the fixture frame 6 , glue is injected into the glue injection grooves through the glue injection holes.

[0096] The off-axis concave parabola reflector detection system is arranged in the order from one side to the other side: interferometer 3, auxiliary plane reflector assembly, off-axis concave parabola reflector assembly, laser level 9 and reference wall 10.

[0097] Example 2

[0098] On the basis of Example 1, this embodiment further discloses a method for detecting an off-axis concave parabolic reflector based on the aberration-free point method, which is implemented by applying the off-axis concave parabolic reflector detection system of Example 1, and includes the following steps:

[0099] S1. Establish a detection benchmark: install a laser level 9 on the air-floating optical platform 1, and install a reference wall on one side of the air-floating optical platform 1; obtain a reference light 1001 as a reference benchmark based on the laser on one side of the laser level 9 and the reference wall 10; specifically: adjust the fourth six-dimensional adjustment stage 204 corresponding to the laser level 9, and align the orthogonal laser light emitted by the laser level 9 with the optical axis of the interferometer 3. The laser on one side of the laser level 9 is presented on the reference wall 10 as a reference benchmark.

[0100] S2. Perform a reference adjustment on the interferometer 3 mounted on the air-floating optical platform 1: Figure 3 As shown, the laser on the other side of the laser level 9 is used to indicate the reference of the interferometer 3, so that the first reflected light 1002 reflected by a pair of orthogonal plane reflectors in the direction of the interferometer 3 lens to the reference wall 10 coincides with the reference light 1001. Figure 4 , complete the initial reference adjustment of the interferometer 3; specifically: the laser on the other side of the laser level 9 is presented to the first reflector 301 and the second reflector 302 set in the interferometer 3, and the laser is reflected to the reference wall 10 by the first reflector 301 and the second reflector 302, and compared with the original reference light 1001, by adjusting the azimuth and pitch direction of the first six-dimensional adjustment platform 201 under the interferometer 3, the reflected first reflected light 1002 and the original reference light 1001 are adjusted to coincide to complete the initial adjustment. The relative position of the interferometer 3 lens and the reference wall 10 is parallel.

[0101] S3. The auxiliary plane reflector 4 mounted on the air-floating optical platform 1 is adjusted to the base: Figure 5 As shown, the laser on the other side of the laser level 9 is used to indicate the reference of the auxiliary plane reflector 4, so that the second reflected light 1003 reflected by the auxiliary plane reflector 4 to the reference wall 10 coincides with the reference light 1001. Figure 6 , complete the initial reference adjustment of the auxiliary plane reflector 4; specifically: after adjusting the interferometer 3, adjust the auxiliary plane mirror assembly. The reflective surface of the auxiliary plane reflector 4 is placed close to the intersection of the focus of the concave parabolic reflector 8 and the focus of the interferometer 3, and the reflective surface of the auxiliary plane reflector 4 is facing away from the direction of the interferometer 3 lens, and the optical axis of the auxiliary plane reflector 4 is adjusted to be consistent with the optical axis of the interferometer 3. Figure 6Similarly, the laser on one side of the laser level 9 is presented on the reference wall 10 as a reference, and the laser on the other side is presented to the reflection surface of the auxiliary plane reflector 4, and the laser is reflected by the reflection surface to the reference wall 10, which is compared with the original reference light 1001. By adjusting the azimuth and pitch direction of the second six-dimensional adjustment platform 202 under the auxiliary plane reflector assembly, the reflected second reflected light 1003 is overlapped with the original reference light 1001 to complete the initial adjustment. The relative position of the auxiliary plane reflector 4 and the reference wall 10 is parallel.

[0102] S4. The off-axis concave parabolic reflector 8 mounted on the air-floating optical platform 1 is adjusted to the base: Figure 8 The laser on the other side of the laser level 9 is used to provide a reference indication for the off-axis concave parabolic reflector 8, so that the third reflected light 1004 reflected by a pair of orthogonally arranged plane reflectors on the fixture frame 6 to the reference wall 10 coincides with the reference light 1001, thereby completing the initial reference adjustment of the off-axis concave parabolic reflector 8; specifically: after adjusting the auxiliary plane reflector 4, adjust the off-axis concave parabolic reflector assembly. The center of the off-axis concave parabolic reflector 8 is aligned with the optical axis position of the interferometer 3 by adjusting the corresponding third six-dimensional adjustment table 203. Similarly, the laser on one side of the laser level 9 is presented on the reference wall 10 as a reference reference, and the laser on the other side is presented to the third reflector 601 and the fourth reflector 602 set on the fixture frame 6. The laser is reflected by the reflection surfaces of the third reflector 601 and the fourth reflector 602 to the reference wall 10, forming a contrast with the original reference light 1001. Fig. 9 By adjusting the azimuth and pitch direction of the third six-dimensional adjustment platform 203 below the off-axis concave parabola reflector 8 assembly, the reflected third reflected light 1004 is overlapped with the original reference light 1001 to complete the initial adjustment. The back of the off-axis concave parabola reflector 8 is parallel to the reference wall 10.

[0103] S5. After adjustment, the interferometer 3, the auxiliary plane reflector 4 assembly, the off-axis concave parabolic reflector 8 assembly and the reference wall 10 are all kept in a relatively parallel relationship. According to the optical design result of the off-axis concave parabolic reflector 8, by adjusting the displacement of the corresponding six-dimensional adjustment device, according to the off-axis amount and the displacement in the optical axis direction, the focus of the off-axis concave parabolic reflector 8 is adjusted to coincide with the focus of the interferometer 3, so that the measuring light beam emitted by the interferometer 3 is incident on the reflecting surface of the off-axis concave parabolic reflector 8, and is reflected to the auxiliary plane reflector 4, and finally returns to the interferometer 3 along the original path to form interference fringes to complete the detection.

[0104] In this embodiment, step S6 is also included:

[0105] The third six-dimensional adjustment stage 203 corresponding to the off-axis concave parabolic reflector 8 is adjusted to adjust the defocus and coma terms of the Zernike coefficient to less than 0.003 wavelengths, so as to improve the measurement accuracy.

[0106] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An off-axis concave parabolic reflector detection system based on the aberration-free point method, characterized in that: include: Interferometer reference components, auxiliary plane reflector reference components, and off-axis concave parabolic reflector reference components; The reference datum of the detection system is a reference light (1001) formed by the laser from one side of the laser level (9) projecting onto the reference wall (10); The interferometer reference component is composed of a pair of plane reflectors arranged orthogonally in the direction of the lens of the laser level (9) and the interferometer (3) and a reference wall (10) connected in sequence by optical paths, so that the light reflected by the plane reflector to the reference wall (10) coincides with the reference light (1001); The auxiliary plane reflector reference component is formed by optically connecting the laser on the other side of the laser level (9) and the reflective surface of the auxiliary plane reflector (4) of the auxiliary plane reflector assembly and the reference wall (10) in sequence, so that the light reflected by the auxiliary plane reflector (4) to the reference wall (10) coincides with the reference light (1001); The off-axis concave parabolic reflector reference component is formed by optically connecting a laser on the other side of a laser level (9) and a pair of orthogonally arranged plane reflectors on a fixture frame (6) of the off-axis concave parabolic reflector assembly and a reference wall (10) in sequence, so that the light reflected by the plane reflector to the reference wall (10) coincides with the reference light (1001); The interferometer (3), the auxiliary plane reflector (4), the off-axis concave parabola reflector (8) of the off-axis concave parabola reflector assembly, and the reference wall (10) are all in a parallel relative position in a reference state; The focus of the off-axis concave parabolic reflector (8) is adjusted to coincide with the focus of the interferometer (3), and the detection light beam emitted by the interferometer (3) is incident on the reflection surface of the off-axis concave parabolic reflector (8), reflected to the auxiliary plane reflector (4), and finally returned to the interferometer (3) along the original path to form interference fringes; The interferometer (3), the auxiliary plane reflector assembly, the off-axis concave parabolic reflector assembly and the laser level (9) are respectively installed on the air-floating optical platform (1) via a six-dimensional adjustment device.

2. The off-axis concave parabola reflector detection system according to claim 1, characterized in that: The auxiliary plane reflector assembly is composed of an auxiliary plane reflector (4) and a matching plane reflector mounting frame (5); The auxiliary plane reflector (4) is mounted on the corresponding six-dimensional adjustment device via a plane reflector mounting frame (5).

3. The off-axis concave parabola reflector detection system according to claim 2, characterized in that: The off-axis concave parabolic reflector assembly is composed of a fixture frame (6), a reflector chamber (7) and an off-axis concave parabolic reflector (8); The off-axis concave parabolic reflector (8) is mounted in a reflector chamber (7), the reflector chamber (7) is mounted on a tooling frame (6), and the tooling frame (6) is mounted on a corresponding six-dimensional adjustment device.

4. The off-axis concave parabola reflector detection system according to claim 3, characterized in that: A circular hole is provided in the middle of the auxiliary plane reflector (4); The reflecting surface of the auxiliary plane reflecting mirror (4) faces away from the lens direction of the interferometer (3); The reflecting surface of the auxiliary plane reflecting mirror (4) is close to the intersection position of the focus of the off-axis concave parabolic reflecting mirror (8) and the focus of the interferometer (3); The optical axis of the auxiliary plane reflector (4) coincides with the optical axis of the interferometer (3).

5. The off-axis concave parabola reflector detection system according to claim 4, characterized in that: A pair of plane reflectors arranged orthogonally in the direction of the lens of the interferometer (3) comprises: a first reflector (301) and a second reflector (302); A first reflector (301) and a second reflector (302) are arranged on the interferometer (3) in a direction parallel to the interferometer lens, and the first reflector (301) and the second reflector (302) are arranged orthogonally.

6. The off-axis concave parabola reflector detection system according to claim 5, characterized in that: The center of the off-axis concave parabolic reflector (8) is aligned with the optical axis position of the interferometer (3); The reflecting surface of the off-axis concave parabolic reflector (8) faces the lens side of the interferometer (3); The reflecting surfaces of a pair of orthogonally arranged plane reflectors on the tooling frame (6) face away from the lens direction of the interferometer (3).

7. The off-axis concave parabola reflector detection system according to claim 6, characterized in that: A pair of orthogonally arranged plane reflectors on the tooling frame (6) comprises: a third reflector (601) and a fourth reflector (602); The tooling frame (6) is provided with grooves for accommodating the third reflector (601) and the fourth reflector (602), and the groove for accommodating the third reflector (601) and the groove for accommodating the fourth reflector (602) are arranged orthogonally; Each groove is provided with axially evenly distributed glue injection grooves on its circumference.

8. A method for detecting an off-axis concave parabolic reflector based on an aberration-free point method, characterized in that: The off-axis concave parabolic reflector detection system according to claim 7 is implemented, comprising the following steps: S1. Establishing a detection reference: installing a laser level (9) on the air-floating optical platform (1), and installing a reference wall on one side of the air-floating optical platform (1); obtaining a reference light (1001) as a reference reference based on the laser on one side of the laser level (9) and the reference wall (10); S2. Performing a reference indication on the interferometer (3) mounted on the air-floating optical platform (1): using the laser on the other side of the laser level (9) to perform a reference adjustment on the interferometer (3), so that the first reflected light (1002) reflected by a pair of orthogonally arranged plane reflectors in the direction of the lens of the interferometer (3) to the reference wall (10) coincides with the reference light (1001), thereby completing the initial reference adjustment of the interferometer (3); S3. Performing a reference indication on the auxiliary plane reflector (4) mounted on the air-floating optical platform (1): using the laser on the other side of the laser level (9) to perform a reference adjustment on the auxiliary plane reflector (4), so that the second reflected light (1003) reflected by the auxiliary plane reflector (4) to the reference wall (10) coincides with the reference light (1001), thereby completing the initial reference adjustment of the auxiliary plane reflector (4); S4. Performing a reference indication on the off-axis concave parabolic reflector (8) mounted on the air-floating optical platform (1): using the laser on the other side of the laser level (9) to perform a reference adjustment on the off-axis concave parabolic reflector (8), so that the third reflected light (1004) reflected by a pair of orthogonally arranged plane reflectors on the fixture frame (6) to the reference wall (10) coincides with the reference light (1001), thereby completing the initial reference adjustment of the off-axis concave parabolic reflector (8); S5. According to the optical design result of the off-axis concave parabolic reflector (8), by adjusting the displacement of the corresponding six-dimensional adjustment device, according to the off-axis amount and the displacement in the optical axis direction, the focus of the off-axis concave parabolic reflector (8) is adjusted to coincide with the focus of the interferometer (3), so that the measuring light beam emitted by the interferometer (3) is incident on the reflecting surface of the off-axis concave parabolic reflector (8), and is reflected to the auxiliary plane reflector (4), and finally returns to the interferometer (3) along the original path to form interference fringes; The method further comprises step S6: adjusting the six-dimensional adjustment device corresponding to the off-axis concave parabolic reflector (8) to adjust the defocus and coma terms of the Zernike coefficient to less than 0.003 wavelengths, thereby completing the detection.

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