A reflector thermal deformation testing device and method

Abstract

The invention provides a reflector thermal deformation testing device and method, and relates to the technical field of optical alignment and detection. The testing device comprises an interferometer, a three-comprehensive test box, a standard plane reflector, a first window glass, a second window glass and a holographic original. Firstly, the thermal deformation of the window glasses on both sides of the three-comprehensive test box is measured, and then the thermal deformation of the reflector to be measured is measured, and the surface errors caused by the two thermal deformations are analyzed and calculated to obtain the Zernike polynomial coefficient value of the reflector to be measured. The surface value of the reflector to be measured is obtained through fitting analysis, which is the thermal deformation of the reflector to be measured. The problem that it is difficult to accurately measure the surface shape change under the actual load working environment and the influence of the window glass on the reflector to be measured in the prior art is solved, and the test accuracy is improved. In addition, the surface error of the reflector to be measured can be quantitatively analyzed through the Zernike polynomial coefficient values ​​of each item in the test result.

Description

Technical Field

[0001] The invention relates to the technical field of optical alignment and detection, and in particular to a device and method for testing thermal deformation of a reflector. Background Art

[0002] Reflectors are widely used in aerospace optoelectronic payloads and are the core components of optoelectronic payload imaging systems. Their surface quality has a great impact on the imaging quality of the system. Existing reflector surface detection is mostly based on measurements in normal temperature and pressure environments. However, the working environment of airborne optoelectronic products is relatively harsh. The temperature range of the working environment is usually around -55 degrees to +60 degrees, and the air pressure is relatively low. Existing test methods are difficult to measure the surface changes in the actual payload working environment.

[0003] A Chinese patent with publication number CN106768885B discloses a device and a method for testing the resolution of a reflector. It proposes a method for measuring the resolution of a reflector at different temperatures using a collimator, a high and low temperature test chamber and other equipment, but the measurement result cannot be quantified, the measurement accuracy is low, and it cannot simulate the changes in air pressure and humidity in the actual working environment of the load. Secondly, the test method of heating the inner and outer surfaces of the light window of the high and low temperature test chamber by a heating film to make the temperature of the two sides of the light window consistent, thereby eliminating the thermal deformation of the light window, has a large error, and the measurement result cannot completely eliminate the situation where the resolution of the plane mirror to be tested is reduced due to the thermal deformation of the light window. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a reflector thermal deformation testing device and method.

[0005] A reflector thermal deformation testing device comprises: an interferometer, a three-comprehensive test box and a standard plane reflector which are arranged in sequence in a transverse direction, a first window glass is arranged on a side of the three-comprehensive test box close to the interferometer, a second window glass is arranged on a side of the three-comprehensive test box close to the standard plane reflector, a reflector to be tested is arranged in the three-comprehensive test box between the first window glass and the second window glass, a holographic original is also arranged between the interferometer and the first window glass, a light beam emitting end of the interferometer, the holographic original, the first window glass, the reflector to be tested, the second window glass and the standard plane reflector are located on the same horizontal line, and the light beam emitting end of the interferometer, the holographic original, the reflector to be tested and the standard plane reflector are parallel to each other, and the surface shape of the first window glass and the second window glass is the same.

[0006] Furthermore, the testing device also includes a first six-dimensional adjustment platform and a second six-dimensional adjustment platform, the standard plane reflector is installed on the first six-dimensional adjustment platform, and the reflector to be tested is installed on the second six-dimensional adjustment platform.

[0007] Furthermore, the testing device also includes a computer control system, which is communicatively connected to the first six-dimensional adjustment platform and the second six-dimensional adjustment platform.

[0008] Furthermore, the light beam emitting end of the interferometer is in a non-parallel position relationship with the first window glass and the second window glass.

[0009] Furthermore, the testing device also includes an optical platform, and the interferometer is installed on the optical platform.

[0010] Furthermore, the holographic original is mounted on an optical platform.

[0011] The present invention also includes a reflector thermal deformation testing method, which is implemented based on the reflector thermal deformation testing device described in any one of the above items, and the testing method includes the following steps:

[0012] Step S1, placing the interferometer, the three-comprehensive test box and the standard plane reflector in sequence horizontally, and starting the interferometer;

[0013] Step S2, starting the three-comprehensive test box, and adjusting the temperature, air pressure and humidity of the three-comprehensive test box to meet the test environment conditions;

[0014] Step S3, controlling the interferometer to emit a detection beam from the beam emission end, and adjusting the posture of the standard plane reflector so that the detection beam emitted by the interferometer is reflected to the center of the field of view of the interferometer after passing through the standard plane reflector;

[0015] Step S4, using an interferometer to measure the surface shape of the standard plane reflector, and obtaining the Zernike polynomial coefficients a1~a1 in the surface shape result of the standard plane reflector. 36 The value of the item;

[0016] Step S5, placing the reflector to be tested in a three-in-one test box between the first window glass and the second window glass, and then placing the holographic original between the interferometer and the first window glass;

[0017] Step S6, adjusting the posture of the reflector to be measured so that the detection light beam emitted by the interferometer passes through the reflector to be measured and is reflected to the center of the field of view of the interferometer;

[0018] Step S7, using an interferometer to measure the surface shape of the reflector to be measured, and obtaining the Zernike polynomial coefficients b1~b1 in the surface shape result of the reflector to be measured. 36 The value of the item;

[0019] Step S8, converting the Zernike polynomial coefficients a1 to a1 in the standard plane reflector surface shape result in step S4 into 36 Multiply the value of the term by one half to obtain the corresponding thermal deformation Zernike polynomial coefficients c1~c36 The value of the item, and then the Zernike polynomial coefficients b1~b in the reflector surface type result to be measured in step S7 36 The value of the term corresponds to the thermal deformation Zernike polynomial coefficient c1~c minus the thermal deformation coefficient c1~c 36 The value of the term is used to obtain the thermal deformation Zernike polynomial coefficients d1~d 36 The value of the item;

[0020] Step S9, converting the thermal deformation Zernike polynomial coefficients d1 to d 36 The value of the item is fitted to obtain the real surface value of the reflector to be measured, which is the thermal deformation of the reflector to be measured.

[0021] Furthermore, the detection light beam emitted by the interferometer in step S3 passes through the first window glass and the second window glass in sequence, then enters the standard plane reflector, is reflected by the standard plane reflector, then passes through the second window glass and the first window glass in sequence, and finally reflects to the center of the field of view of the interferometer.

[0022] Furthermore, the detection light beam emitted by the interferometer in step S6 passes through the holographic original and the first window glass in sequence, then enters the reflector to be measured, is reflected by the reflector to be measured, then passes through the first window glass and the holographic original in sequence, and finally reflects to the center of the field of view of the interferometer.

[0023] Furthermore, in step S3, the first six-dimensional adjustment platform is controlled by a computer control system to adjust the posture of the standard plane reflector, and in step S6, the second six-dimensional adjustment platform is controlled by a computer control system to adjust the posture of the reflector to be measured.

[0024] The technical solution of the present invention has the following advantages:

[0025] 1. The present invention provides a reflector thermal deformation testing device and method. First, a standard plane reflector is used to measure the thermal deformation of the window glasses on both sides of the three-integrated test box, that is, the thermal deformation of the first window glass and the second window glass. At this time, the surface shape result includes the thermal deformation of the first window glass and the second window glass. Then, the thermal deformation of the reflector to be measured is measured. At this time, the thermal deformation test result of the reflector to be measured includes the thermal deformation of the first window glass. The surface shape errors caused by the two thermal deformations are analyzed and calculated to obtain the Zernike polynomial coefficient value of the reflector to be measured. The surface shape value of the reflector to be measured is obtained by fitting analysis, which is the thermal deformation of the reflector to be measured. Compared with the traditional reflector thermal deformation measurement method, the present invention eliminates the window glass to the reflector to be measured. In addition, the surface error of the reflector to be tested can be quantitatively analyzed through the Zernike polynomial coefficient values ​​of each item in the test results to ensure that the surface shapes of the first window glass and the second window glass are the same. In order to more accurately calculate the thermal deformation Zernike polynomial coefficient values ​​of a single window glass and improve the measurement accuracy, the beam emission end of the interferometer, the holographic original, the first window glass, the reflector to be tested, the second window glass and the standard plane reflector are located on the same horizontal line, and the beam emission end of the interferometer, the holographic original, the reflector to be tested and the standard plane reflector are parallel to each other to ensure the normal transmission and reflection of the light beam emitted by the interferometer during the measurement process. The interferometer needs a holographic original to change the wavefront of the light to measure the concave parabolic mirror during the measurement process.

[0026] 2. In the technical solution provided by the present invention, the posture adjustment of the standard plane reflector and the reflector to be measured is more convenient and more accurate by controlling the first six-dimensional adjustment platform and the second six-dimensional adjustment platform through a computer control system. The non-parallel position relationship between the light beam emission end of the interferometer and the first window glass and the second window glass prevents the possibility of stray light in the interferometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 It is a schematic diagram of the structure of the present invention when measuring the thermal deformation of the first window glass and the second window glass;

[0029] Figure 2 It is a schematic diagram of the structure of the present invention when measuring the thermal deformation of the reflector to be measured.

[0030] Description of reference numerals:

[0031] 1-interferometer; 2-first window glass; 3-three-integrated test box; 4-second window glass; 5-standard plane reflector; 6-first six-dimensional adjustment platform; 7-optical platform; 8-reflector to be tested; 9-second six-dimensional adjustment platform; 10-computer control system; 11-holographic original. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] like Figure 1 and Figure 2The device for testing thermal deformation of a reflector shown in the figure comprises: an interferometer 1, a three-comprehensive test box 3 and a standard plane reflector 5 which are arranged in sequence in a transverse direction, a first window glass 2 is arranged on the side of the three-comprehensive test box 3 close to the interferometer 1, a second window glass 4 is arranged on the side of the three-comprehensive test box 3 close to the standard plane reflector 5, a reflector 8 to be tested is arranged in the three-comprehensive test box 3 between the first window glass 2 and the second window glass 4, a holographic original 11 is further arranged between the interferometer 1 and the first window glass 2, a light beam emitting end of the interferometer 1, the holographic original 11, the first window glass 2, the reflector 8 to be tested, the second window glass 4 and the standard plane reflector 5 are located on the same horizontal line, and the light beam emitting end of the interferometer 1, the holographic original 11, the reflector 8 to be tested and the standard plane reflector 5 are parallel to each other, and the first window glass 4 is arranged between the first window glass 2 and the second window glass 4. The surface shapes of the first window glass 2 and the second window glass 4 are the same. It should be noted that, under ideal conditions, the surface shapes of the first window glass 2 and the second window glass 4 are the same, but in real life, it is difficult to control the surface shapes of the first window glass 2 and the second window glass 4 to be exactly the same. Therefore, in the actual application of the present invention, the first window glass 2 and the second window glass 4 are measured for surface shape before being installed on the three-integrated test box 3 to ensure that the surface shapes of the first window glass 2 and the second window glass 4 are similar, and the coefficient values ​​of the Zernike polynomials of the first window glass 2 and the second window glass 4 are not much different. It is also necessary to ensure that the test light beam emitted by the interferometer 1 can pass through the first window glass 2 and the second window glass 4. The interferometer 1 and the standard plane reflector 5 are both arranged outside the three-integrated test box 3.

[0037] The above-mentioned reflector thermal deformation testing device first uses a standard plane reflector 5 to measure the thermal deformation of the window glasses on both sides of the three-integrated test box 3, that is, the thermal deformation of the first window glass 2 and the second window glass 4. At this time, the surface shape result includes the thermal deformation of the first window glass 2 and the second window glass 4. Then, the thermal deformation of the reflector 8 to be tested is measured. At this time, the thermal deformation test result of the reflector 8 to be tested includes the thermal deformation of the first window glass 2. The surface shape errors caused by the two thermal deformations are analyzed and calculated to obtain the Zernike polynomial coefficient value of the reflector 8 to be tested. The surface shape value of the reflector 8 to be tested is obtained through fitting analysis, which is the thermal deformation of the reflector 8 to be tested. Compared with the traditional reflector thermal deformation measurement method, the present invention eliminates the influence of the window glass on the reflector 8 to be tested, improves the test accuracy, and in addition, through the test results The Zernike polynomial coefficient values ​​of each item can quantitatively analyze the surface error of the reflector 8 to be measured, and ensure that the surface shapes of the first window glass 2 and the second window glass 4 are the same. In order to more accurately calculate the thermal deformation Zernike polynomial coefficient values ​​of a single window glass and improve the measurement accuracy, the light beam emitting end of the interferometer 1, the holographic original 11, the first window glass 2, the reflector 8 to be measured, the second window glass 4 and the standard plane reflector 5 are located on the same horizontal line, and the light beam emitting end of the interferometer 1, the holographic original 11, the reflector 8 to be measured and the standard plane reflector 5 are parallel to each other, which ensures the normal transmission and reflection of the light beam emitted by the interferometer 1 during the measurement process. The interferometer 1 needs the holographic original 11 to change the wavefront of the light to measure the concave parabolic mirror during the measurement process. The reflector 8 to be measured can be a reflector of the type of a plane reflector, a spherical mirror, or an aspherical mirror.

[0038] like Figure 1 and Figure 2 As shown, in this embodiment, the testing device also includes a first six-dimensional adjustment platform 6 and a second six-dimensional adjustment platform 9, the standard plane mirror 5 is installed on the first six-dimensional adjustment platform 6, and the reflector 8 to be tested is installed on the second six-dimensional adjustment platform 9; during the test, the first six-dimensional adjustment platform 6 adjusts the posture of the standard plane mirror 5, and the second six-dimensional adjustment platform 9 adjusts the posture of the reflector 8 to be tested. Using the first six-dimensional adjustment platform 6 and the second six-dimensional adjustment platform 9 to perform posture adjustment can not only perform adjustments in multiple degrees of freedom, but also ensure the accuracy of the adjustment process, thereby increasing the accuracy of the test results.

[0039] like Figure 1 and Figure 2 As shown, in this embodiment, the testing device also includes a computer control system 10, which is communicatively connected with the first six-dimensional adjustment platform 6 and the second six-dimensional adjustment platform 9; during the test, the first six-dimensional adjustment platform 6 and the second six-dimensional adjustment platform 9 are controlled and adjusted by the computer control system 10, thereby realizing the posture adjustment of the standard plane reflector 5 and the reflector to be tested 8.

[0040] like Figure 1 and Figure 2 As shown, in this embodiment, the light beam emitting end of the interferometer 1 is in a non-parallel position relationship with the first window glass 2 and the second window glass 4; if the light beam emitting end of the interferometer 1 is in a parallel position relationship with the first window glass 2 and the second window glass 4, since the light beam emitted by the interferometer 1 passes through the first window glass 2 and the second window glass 4, stray light will appear in the interferometer 1, affecting normal testing. Therefore, the light beam emitting end of the interferometer 1 is in a non-parallel position relationship with the first window glass 2 and the second window glass 4, but the inclination angle between the light beam emitting end of the interferometer 1 and the first window glass 2 and the second window glass 4 cannot be too large, and it is sufficient to ensure that there is no angle visible to the naked eye.

[0041] like Figure 1 and Figure 2 As shown, in this embodiment, the test device also includes an optical platform 7, and the interferometer 1 is installed on the optical platform 7; the optical platform 7 supports and places the interferometer 1, ensuring that the light beam emission end of the interferometer 1, the holographic original 11, the first window glass 2, the reflector to be tested 8, the second window glass 4 and the standard plane reflector 5 are located on the same horizontal line.

[0042] like Figure 1 and Figure 2 As shown, in this embodiment, the holographic original 11 is installed on the optical platform 7; the optical platform 7 supports and places the holographic original 11, ensuring that the light beam emission end of the interferometer 1, the holographic original 11, the first window glass 2, the reflector to be measured 8, the second window glass 4 and the standard plane reflector 5 are located on the same horizontal line.

[0043] like Figure 1 and Figure 2 As shown, the present invention also includes a reflector thermal deformation testing method, which is implemented based on a reflector thermal deformation testing device as described in any one of the above items, and the testing method includes the following steps:

[0044] Step S1, placing the interferometer 1, the three-comprehensive test box 3 and the standard plane reflector 5 in sequence horizontally, and starting the interferometer 1;

[0045] Step S2, starting the three-comprehensive test box 3, and adjusting the temperature, air pressure and humidity of the three-comprehensive test box 3 to meet the test environment conditions;

[0046] Step S3, controlling the interferometer 1 to emit a detection beam from the beam emission end, and adjusting the posture of the standard plane reflector 5 so that the detection beam emitted by the interferometer 1 passes through the standard plane reflector 5 and is reflected to the center of the field of view of the interferometer 1;

[0047] Step S4, using the interferometer 1 to measure the surface shape of the standard plane reflector 5, and obtaining the Zernike polynomial coefficients a1~a1 in the surface shape result of the standard plane reflector 5 36 The measured surface result at this time includes the thermal deformation of the first window glass 2 and the second window glass 4;

[0048] Step S5, placing the reflector 8 to be tested in the three-integrated test box 3 between the first window glass 2 and the second window glass 4, and then placing the holographic original 11 between the interferometer 1 and the first window glass 2;

[0049] Step S6, adjusting the posture of the reflector 8 to be measured so that the detection light beam emitted by the interferometer 1 passes through the reflector 8 to be measured and is reflected to the center of the field of view of the interferometer 1;

[0050] Step S7, using the interferometer 1 to measure the surface shape of the reflector 8 to be measured, and obtaining the Zernike polynomial coefficients b1~b 36 The measured surface result at this time includes the thermal deformation of the first window glass 2;

[0051] Step S8, since the surface results of the first window glass 2 and the second window glass 4 are similar, and the coefficients of the Zernike polynomials of the first window glass 2 and the second window glass 4 are not much different, the Zernike polynomial coefficients a1~a1 in the surface result of the standard plane reflector 5 in step S4 are 36 The value of the term is multiplied by one half to obtain the corresponding thermal deformation Zernike polynomial coefficients c1~c 36 The value of the item, and then the Zernike polynomial coefficients b1~b in the surface shape result of the reflector to be tested in step S7 36 The value of the term corresponds to the thermal deformation Zernike polynomial coefficients c1~c minus the thermal deformation Zernike polynomial coefficients c1~c 36 The value of the item is used to obtain the thermal deformation Zernike polynomial coefficients d1~d 36 The value of the item;

[0052] Step S9, converting the thermal deformation Zernike polynomial coefficients d1 to d 36 The value of the item is fitted to obtain the real surface value of the reflector 8 to be measured, that is, the thermal deformation of the reflector 8 to be measured.

[0053] like Figure 1 and Figure 2 As shown, in this embodiment, the detection light beam emitted by the interferometer 1 in step S3 passes through the first window glass 2 and the second window glass 4 in sequence, then enters the standard plane reflector 5, is reflected by the standard plane reflector 5, then passes through the second window glass 4 and the first window glass 2 in sequence, and is finally reflected to the center of the field of view of the interferometer 1.

[0054] like Figure 1 and Figure 2 As shown, in this embodiment, the detection light beam emitted by the interferometer 1 in step S6 passes through the holographic original 11 and the first window glass 2 in sequence, and then is incident on the reflector 8 to be measured, and after being reflected by the reflector 8 to be measured, it passes through the first window glass 2 and the holographic original 11 in sequence, and is finally reflected to the center of the field of view of the interferometer 1.

[0055] like Figure 1 and Figure 2 As shown, in this embodiment, in step S3, the first six-dimensional adjustment platform 6 is controlled by the computer control system 10 to adjust the posture of the standard plane mirror 5, and in step S6, the second six-dimensional adjustment platform 9 is controlled by the computer control system 10 to adjust the posture of the reflector to be measured 8.

[0056] like Figure 1 and Figure 2 As shown, in this embodiment, according to a reflector thermal deformation testing device and method provided by the present invention, a measuring experiment is performed on a reflector 8 to be tested under a temperature environment of 60° C. The reflector 8 to be tested is an aspherical reflector. The specific testing method and process are as follows:

[0057] Process 1, placing the interferometer 1, the three-integrated test box 3 and the standard plane reflector 5 in sequence horizontally, starting the interferometer 1, and installing the standard plane reflector 5 on the first six-dimensional adjustment platform 6;

[0058] Process 2: start the three-comprehensive test box 3, and adjust the temperature, air pressure and humidity of the three-comprehensive test box 3 to meet the test environment conditions. Specifically, adjust the temperature of the three-comprehensive test box 3 to 60° C., the air pressure to 19300 Pa, and the relative humidity to 30%;

[0059] Process three, controlling the interferometer 1 to emit a detection beam from the beam emission end, and controlling the first six-dimensional adjustment platform 6 through the computer control system 10 to further adjust the posture of the standard plane reflector 5, so that the detection beam emitted by the interferometer 1 passes through the standard plane reflector 5 and is reflected to the center of the field of view of the interferometer 1;

[0060] Process 4: Use interferometer 1 to measure the surface shape of standard plane reflector 5, and obtain the Zernike polynomial coefficients a1~a in the surface shape result of standard plane reflector 5 36 The measured surface result at this time includes the thermal deformation of the first window glass 2 and the second window glass 4;

[0061] Process five, placing the reflector 8 to be tested in the three-integrated test box 3 between the first window glass 2 and the second window glass 4, and then placing the holographic original 11 between the interferometer 1 and the first window glass 2;

[0062] Process six, controlling the second six-dimensional adjustment platform 9 through the computer control system 10 to adjust the posture of the reflector 8 to be measured, so that the detection light beam emitted by the interferometer 1 passes through the reflector 8 to be measured and then reflects to the center of the field of view of the interferometer 1;

[0063] Step 7: Use interferometer 1 to measure the surface shape of the reflector 8 to be measured, and obtain the Zernike polynomial coefficients b1~b in the surface shape result of the reflector 8 to be measured. 36 The values ​​of the items are: b1=-3.002, b2=0.219, b3=3.513, b4=-0.091, b5=0.01, b6=0.062, b7=0.108, b8=0.068, b9=-0.084, b 10 =-0.118, b 11 =-0.059, b 12 =-0.023, b 13 =-0.019, b 14 =0.072, b 15 =0.026, b 16 =0.181, b 17 =0.006, b 18 =-0.046, b 19 =-0.06, b 20 =0.119, b 21 =0.002, b 22 =-0.015, b 23 =0.014, b 24 =-0.005, b 25 =-0.032, b 26 =0.015, b 27 =0.055, b 28 =0.002, b 29 =-0.035, b 30 =-0.018, b 31 =-0.006, b 32 =-0.005, b 33 =-0.011, b 34 =0.003, b 35 =-0.006, b 36 =0.006; the measured surface result at this time includes the thermal deformation of the first window glass 2;

[0064] In process eight, since the surface results of the first window glass 2 and the second window glass 4 are similar, and the coefficients of the Zernike polynomials of the first window glass 2 and the second window glass 4 are not much different, the Zernike polynomial coefficients a1~a1 in the surface result of the standard plane reflector 5 in process four are changed to 36The value of the term is multiplied by one half to obtain the corresponding thermal deformation Zernike polynomial coefficients c1~c 36 The values ​​of the items are: c1=0.046, c2=-0.016, c3=0.360, c4=-0.053, c5=-0.002, c6=0.036, c7=0.128, c8=0.078, c9=-0.108, c 10 =-0.110, c 11 =-0.012, c 12 =-0.027, c 13 =0.034, c 14 =0.072, c 15 =0.017, c 16 =0.191, c 17 =-0.006, c 18 =-0.072, c 19 =-0.066, c 20 =0.035, c 21 =0.006, c 22 =-0.011, c 23 =0.017, c 24 =-0.002, c 25 =-0.016, c 26 =0.021, c 27 =0.063, c 28 =0.006, c 29 =-0.025, c 30 =-0.017, c 31 =0.012, c 32 =-0.003, c 33 =-0.006, c 34 =0.002, c 35 =-0.005, c 36 =0.001;

[0065] Then use the Zernike polynomial coefficients b1~b in the surface shape result of the reflector to be tested in process 7 36 The value of the term corresponds to the thermal deformation Zernike polynomial coefficients c1~c minus the thermal deformation Zernike polynomial coefficients c1~c 36 The value of the item is used to obtain the thermal deformation Zernike polynomial coefficients d1~d 36 The values ​​of the items are: d1=-3.048, d2=0.235, d3=3.153, d4=-0.038, d5=0.012, d6=0.026, d7=-0.02, d8=-0.01, d9=0.024, d 10 =-0.008, d 11=-0.047, d 12 =0.004, d 13 =0.015, d 14 =-0、d 15 =0.009, d 16 =-0.01, d 17 =0.012, d 18 =0.026, d 19 =0.006, d 20 =0.084, d 21 =-0.004, d 22 =-0.004, d 23 =-0.003, d 24 =-0.003, d 25 =-0.016, d 26 =-0.006, d 27 =-0.008, d 28 =-0.004, d 29 =-0.01, d 30 =-0.001, d 31 =-0.018, d 32 =-0.002, d 33 =-0.005, d 34 =0.001, d 35 =-0.001, d 36 =0.005;

[0066] Step nine: transform the thermal deformation Zernike polynomial coefficients d1 to d 36 The value of the item is fitted to obtain the real surface value of the reflector 8 to be measured, that is, the thermal deformation of the reflector 8 to be measured. The real surface value of the reflector 8 to be measured is obtained through fitting analysis, RMS=0.041@632.8nm.

[0067] 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. A reflector thermal deformation testing device, characterized in that: include: An interferometer (1), a three-comprehensive test box (3), and a standard plane reflector (5) are arranged in sequence in a transverse direction. A first window glass (2) is arranged on a side of the three-comprehensive test box (3) close to the interferometer (1). A second window glass (4) is arranged on a side of the three-comprehensive test box (3) close to the standard plane reflector (5). A reflector to be measured (8) is arranged in the three-comprehensive test box (3) between the first window glass (2) and the second window glass (4). A holographic element (11) is also arranged between the interferometer (1) and the first window glass (2). The light beam emitting end of the interferometer (1), the holographic element (11), the first window glass (2), the reflector to be measured (8), the second window glass (4), and the standard plane reflector (5) are located on the same horizontal line. The light beam emitting end of the interferometer (1), the holographic element (11), the reflector to be measured (8), and the standard plane reflector (5) are parallel to each other. The surface shapes of the first window glass (2) and the second window glass (4) are the same.

2. A reflector thermal deformation testing device according to claim 1, characterized in that: The testing device further comprises a first six-dimensional adjustment platform (6) and a second six-dimensional adjustment platform (9), the standard plane reflector (5) being mounted on the first six-dimensional adjustment platform (6), and the reflector to be tested (8) being mounted on the second six-dimensional adjustment platform (9).

3. A reflector thermal deformation testing device according to claim 2, characterized in that: The testing device further comprises a computer control system (10), wherein the computer control system (10) is communicatively connected to the first six-dimensional adjustment platform (6) and the second six-dimensional adjustment platform (9).

4. A reflector thermal deformation testing device according to claim 1, characterized in that: The light beam emission end of the interferometer (1) is in a non-parallel position relationship with the first window glass (2) and the second window glass (4).

5. The reflector thermal deformation testing device according to claim 1, characterized in that: The testing device also includes an optical platform (7), and the interferometer (1) is mounted on the optical platform (7).

6. A reflector thermal deformation testing device according to claim 5, characterized in that: The holographic original (11) is mounted on an optical platform (7).

7. A method for testing thermal deformation of a reflector, the method being implemented based on the device for testing thermal deformation of a reflector according to any one of claims 1 to 6, characterized in that: The test method comprises the following steps: Step S1, placing the interferometer (1), the three-integrated test box (3) and the standard plane reflector (5) in sequence in a horizontal direction, and starting the interferometer (1); Step S2, starting the three-comprehensive test box (3), and adjusting the temperature, air pressure and humidity of the three-comprehensive test box (3) to meet the test environment conditions; Step S3, controlling the interferometer (1) to emit a detection beam from the beam emission end, and adjusting the posture of the standard plane reflector (5) so that the detection beam emitted by the interferometer (1) passes through the standard plane reflector (5) and is reflected to the center of the field of view of the interferometer (1); Step S4, using the interferometer (1) to measure the surface shape of the standard plane reflector (5), and obtaining the Zernike polynomial coefficients a1~a1 in the surface shape result of the standard plane reflector (5). 36 The value of the item; Step S5, placing the reflector (8) to be tested in the three-integrated test box (3) between the first window glass (2) and the second window glass (4), and then placing the holographic original (11) between the interferometer (1) and the first window glass (2); Step S6, adjusting the posture of the reflector (8) to be measured so that the detection light beam emitted by the interferometer (1) passes through the reflector (8) to be measured and then reflects to the center of the field of view of the interferometer (1); Step S7, using the interferometer (1) to measure the surface shape of the reflector (8) to be measured, and obtaining the Zernike polynomial coefficients b1~b1 in the surface shape result of the reflector (8) to be measured. 36 The value of the item; Step S8, convert the Zernike polynomial coefficients a1~a1 in the surface shape result of the standard plane reflector (5) in step S4 into 36 The value of the term is multiplied by one half to obtain the corresponding thermal deformation Zernike polynomial coefficients c1~c 36 The value of the item is then converted into the Zernike polynomial coefficients b1~b in the surface shape result of the reflector (8) to be measured in step S7. 36 The value of the term corresponds to the thermal deformation Zernike polynomial coefficients c1~c minus the thermal deformation Zernike polynomial coefficients c1~c of the first window glass (2) 36 The value of the term is used to obtain the thermal deformation Zernike polynomial coefficients d1~d 36 The value of the item; Step S9, converting the thermal deformation Zernike polynomial coefficients d1 to d 36 The value of the item is fitted to obtain the actual surface value of the reflector (8) to be measured, that is, the thermal deformation of the reflector (8) to be measured.

8. A reflector thermal deformation testing method according to claim 7, characterized in that: In step S3, the detection light beam emitted by the interferometer (1) sequentially passes through the first window glass (2) and the second window glass (4), then enters the standard plane reflector (5), is reflected by the standard plane reflector (5), then sequentially passes through the second window glass (4) and the first window glass (2), and finally is reflected to the center of the field of view of the interferometer (1).

9. A reflector thermal deformation testing method according to claim 7, characterized in that: In step S6, the detection light beam emitted by the interferometer (1) sequentially passes through the holographic original (11) and the first window glass (2), then is incident on the reflective mirror (8) to be measured, is reflected by the reflective mirror (8), then sequentially passes through the first window glass (2) and the holographic original (11), and is finally reflected to the center of the field of view of the interferometer (1).

10. A reflector thermal deformation testing method according to claim 7, characterized in that: In step S3, the first six-dimensional adjustment platform (6) is specifically controlled by the computer control system (10) to thereby adjust the posture of the standard plane reflector (5), and in step S6, the second six-dimensional adjustment platform (9) is specifically controlled by the computer control system (10) to thereby adjust the posture of the reflector to be measured (8).

Images