Low-temperature optical mirror surface type detection system and method

Abstract

The invention belongs to the technical field of optical mirror surface type detection, and discloses a low-temperature optical mirror surface type detection system and method, and the system comprises a refrigeration device, a refrigeration chamber, a vacuum pump, and a detection device. The refrigerating device is communicated with the refrigerating chamber; the refrigeration chamber is provided with an optical window, and the detection device directly faces the optical window; the refrigerating device is used for providing a low-temperature environment for the refrigerating chamber; the refrigeration chamber is provided with a supporting structure used for supporting the optical component to be detected so that the optical component to be detected can directly face the optical window. The detection device comprises a transmitting module and a processing module, the transmitting module is used for transmitting detection light and converging the detection light to the surface of the to-be-detected optical component through the optical window, and the processing module is used for receiving light reflected by the to-be-detected optical component, forming an interference image and completing low-temperature surface type detection; according to the invention, the refrigeration chamber, the refrigeration device and the vacuum pump are utilized to establish a low-temperature detection environment, and the support structure and the detection device are combined to detect the surface type of the optical mirror surface in the low-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of optical mirror surface shape detection, and in particular to a low-temperature optical mirror surface shape detection system and method. Background Art

[0002] With the development of infrared detection technology, high-sensitivity infrared detection has become a major research direction, with broad application prospects in thermal infrared remote sensing imaging, long-range detection of faint targets, and infrared astronomical deep-space observation. Because the target temperature is near room temperature, its corresponding infrared self-emission peak signal overlaps with the infrared signal emitted by the optical system, which is also at room temperature. The target infrared signal is submerged in the optical system's self-emission signal, making long-range target detection difficult. Therefore, reducing the temperature of the optical system itself can effectively suppress its own infrared radiation and is a necessary means to achieve high-sensitivity infrared detection.

[0003] Cryogenic optical systems operate in relatively low temperature environments, and system design must first meet low-temperature performance requirements. Changes in ambient temperature can affect the refractive index, radius of curvature, aspheric coefficient, and stress caused by thermal expansion and contraction of the optical components. However, existing surface testing of optical components is performed at room temperature and is unsuitable for use in cryogenic environments. Therefore, a method for testing the surface shape of optical components under cryogenic conditions is urgently needed to evaluate their low-temperature performance.

[0004] Optical components need to be tested in a vacuum environment to achieve low temperature, avoiding condensation contamination such as water vapor. Optical components are affected by factors such as material uniformity, low-temperature support method and cold chain fixation. They are prone to low-temperature deformation at low temperatures, causing stress on the optical components and affecting the performance of the optical system. They cannot be directly evaluated at room temperature. Therefore, it is necessary to use low-temperature detection to detect the surface parameters of optical components and evaluate the low-temperature performance of optical components. Summary of the Invention

[0005] The present invention aims to provide a low-temperature optical mirror surface shape detection system and method. This system utilizes a refrigeration chamber, a refrigeration device, and a vacuum pump to create a low-temperature detection environment. Combined with a support structure and a detection device, this system enables the detection of optical mirror surface shape in a low-temperature environment. This solves the problems mentioned in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A low-temperature optical mirror surface detection system includes a refrigeration device, a refrigeration chamber, a vacuum pump, and a detection device; the refrigeration device is connected to the refrigeration chamber; the refrigeration chamber is provided with an optical window, and the detection device faces the optical window; the vacuum pump is connected to the refrigeration chamber;

[0008] The refrigeration device is used to provide a low-temperature environment for the refrigeration chamber;

[0009] The refrigeration chamber is provided with a supporting structure for supporting the optical component to be tested, so that the optical component to be tested faces the optical window;

[0010] The detection device includes a transmitting module and a processing module. The transmitting module is used to emit detection light and converge it to the surface of the optical component to be tested through an optical window. The processing module is used to receive the light reflected by the optical component to be tested and form an interference image to complete low-temperature surface detection.

[0011] Furthermore, the optical window is made of sapphire, and its surface shape is better than 0.03λ.

[0012] Furthermore, the refrigerant is connected to the refrigeration chamber through a flexible cold chain pipe, and the material of the flexible cold chain pipe is alloy and copper; the material of the supporting structure is fiberglass.

[0013] A low-temperature optical mirror surface shape detection method using the low-temperature optical mirror surface shape detection system as described above includes the following steps:

[0014] S1: Fix the optical component to be tested on the support structure and place the detection device on the six-dimensional adjustment frame;

[0015] S2. Build a three-dimensional model of the measurement light path using computer software;

[0016] S3. Close the entrance to the refrigeration chamber and measure using a laser tracker and theodolite precision measuring instrument to control the position deviation and angular deviation of the detection device; and set the parameters of the detection device according to the measurement plan;

[0017] S4. Adjust the translation and angular position of the six-dimensional adjustment frame according to the interference pattern until the RMS of the optical component to be measured meets the requirements;

[0018] S5. The vacuum pump evacuates the refrigeration chamber and records the surface shape of the optical component to be tested at room temperature;

[0019] S6. Liquid nitrogen is passed through the heat sink in the refrigeration chamber to start cooling. After the temperature of the measuring point reaches the target temperature, it is maintained for a preset time. After stabilization, S4 is repeated to record the surface shape of the optical component to be measured under vacuum and low temperature conditions.

[0020] Furthermore, in S3 , the position deviation of the detection device is controlled within 0.1 mm, and the angle deviation is controlled within 1′.

[0021] Furthermore, in S6, the cooling rate is 0.3°C / min, and after the temperature at the measuring point reaches the target temperature, it is maintained for 6 hours.

[0022] The beneficial effects of the technical solution are:

[0023] The present invention provides a low-temperature optical mirror surface shape detection system and method. Using a refrigeration chamber, refrigeration equipment, and a vacuum pump, this system creates a low-temperature detection environment. Combined with a support structure and detection equipment, this system enables low-temperature surface shape detection of optical mirrors in this environment. By detecting the surface parameters of optical components at low temperatures, the low-temperature performance of these components can be evaluated. This solves the problem of optical components being susceptible to low-temperature deformation at low temperatures due to factors such as material uniformity, low-temperature support methods, and cold chain fixation, which affects optical system performance and cannot be directly evaluated at room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a structural schematic diagram of a low-temperature optical mirror surface detection system of the present invention.

[0025] The names of the corresponding symbols in the accompanying drawings are:

[0026] 1. Refrigerator; 2. Flexible cold chain pipeline; 3. Optical components to be tested; 4. Support structure; 5. Optical window; 6. Interferometer; 7. Vacuum tank. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0028] like Figure 1 As shown, a low-temperature optical mirror surface shape detection system includes a refrigeration device, a refrigeration chamber, a vacuum pump and a detection device; the refrigeration chamber is provided with an optical window 5, the material of the optical window 5 is sapphire, and the surface shape is better than 0.03λ (λ=0.632μm), and the detection device is directly opposite the optical window 5; the vacuum pump is connected to the refrigeration chamber;

[0029] A refrigeration device is used to provide a low-temperature environment for the refrigeration chamber. In this embodiment, the refrigeration device is a liquid nitrogen refrigerator 1. The refrigerator 1 is connected to the refrigeration chamber via a flexible cold chain pipe 2. The material of the flexible cold chain pipe 2 is alloy and copper.

[0030] The refrigeration chamber is provided with a support structure 4 for supporting the optical component 3 to be tested, so that the optical component 3 to be tested faces the optical window 5. In this embodiment, the refrigeration chamber can be a vacuum tank 7. The support structure 4 is made of fiberglass, and the optical component 3 to be tested and the support structure 4 adopt a stress-free support method. For example, an elastic gasket is set between the fiberglass and the optical component 3 to be tested. The elastic gasket can be made of a material with good elasticity and aging resistance such as silicone rubber. It can play a buffering role between the concave lens and the fiberglass, and absorb stress caused by factors such as thermal expansion and contraction, mechanical vibration, etc.

[0031] The detection device includes a transmitting module and a processing module. The transmitting module is used to emit detection light and converge it to the surface of the optical component 3 to be tested through the optical window 5. The processing module is used to receive the light reflected by the optical component 3 to be tested and form an interference image to complete low-temperature surface detection.

[0032] In this embodiment, the detection device includes an interferometer 6. The spherical wave emitted by the interferometer 6 converges through an optical window 5 onto the surface of the optical component 3 to be tested. This surface reflects the test light, which then returns to the interferometer 6 through the optical window 5 to form an interference pattern, completing the low-temperature surface test. The interferometer 6 also has a spherical standard lens f# ≤ R / D (where R is the focal length of the optical component 3 to be tested, and D is the aperture of the optical component 3 to be tested).

[0033] A low-temperature optical mirror surface shape detection method using the low-temperature optical mirror surface shape detection system as described above includes the following steps:

[0034] S1: Fix the optical component 3 to be measured on the support structure 4, and place the interferometer 6 on the six-dimensional adjustment frame;

[0035] S2. Build a three-dimensional model of the measurement light path using computer software;

[0036] S3. Close the entrance to the vacuum tank 7 and use precision measuring instruments such as a laser tracker and theodolite to measure the interferometer 6 to ensure that the position deviation is within 0.1 mm and the angle deviation is within 1'. The interferometer 6 parameters, such as the effective aperture and interference factor, are set according to the measurement plan. If the product to be measured is coated with a high-reflectivity film, an attenuator must be placed in front of the interferometer 6.

[0037] S4, adjusting the translation and angular position of the six-dimensional adjustment frame according to the interference pattern until the RMS of the optical component 3 to be measured is optimal;

[0038] S5. Use a vacuum pump to evacuate the vacuum tank 7, repeat step S4, and record the surface shape of the optical component 3 to be tested at room temperature;

[0039] S6: Liquid nitrogen is passed through the cooling chamber to begin cooling the mirror under test at a rate of 0.3°C / min. After the temperature at the measuring point reaches the target temperature, maintain it for 6 hours. Once it stabilizes, repeat S4 and record the surface shape of the optical component under test 3 in the vacuum low-temperature state. The test equipment is then powered off and the test system is allowed to return to temperature.

[0040] In summary, the present invention provides a low-temperature optical mirror surface shape detection system and method, which utilizes a refrigeration chamber, a refrigeration device and a vacuum pump to realize the construction of a low-temperature detection environment, and combines the support structure 4 and the detection device to realize the detection of the surface shape of the optical mirror in a low-temperature environment. By detecting the surface shape parameters of optical components at low temperature, the low-temperature performance of the optical components can be evaluated.

[0041] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A low-temperature optical mirror surface detection system, characterized in that: The invention comprises a refrigeration device, a refrigeration chamber, a vacuum pump and a detection device; the refrigeration device is connected to the refrigeration chamber; the refrigeration chamber is provided with an optical window, and the detection device faces the optical window; the vacuum pump is connected to the refrigeration chamber; The refrigeration device is used to provide a low-temperature environment for the refrigeration chamber; The refrigeration chamber is provided with a supporting structure for supporting the optical component to be tested, so that the optical component to be tested faces the optical window; The detection device includes a transmitting module and a processing module. The transmitting module is used to emit detection light and converge it to the surface of the optical component to be tested through an optical window. The processing module is used to receive the light reflected by the optical component to be tested and form an interference image to complete low-temperature surface detection.

2. A low-temperature optical mirror surface detection system according to claim 1, characterized in that: The optical window is made of sapphire, and its surface shape is better than 0.03λ.

3. The low-temperature optical mirror surface detection system according to claim 1, characterized in that: The refrigerant is connected to the refrigeration chamber through a flexible cold chain pipe, and the material of the flexible cold chain pipe is alloy and copper; the material of the supporting structure is fiberglass.

4. A low-temperature optical mirror surface detection method using a low-temperature optical mirror surface detection system according to claim 1, characterized in that: The following steps are involved: S1: Fix the optical component to be tested on the support structure and place the detection device on the six-dimensional adjustment frame; S2. Build a three-dimensional model of the measurement light path using computer software; S3. Close the entrance to the refrigeration chamber and measure using a laser tracker and theodolite precision measuring instrument to control the position deviation and angular deviation of the detection device; and set the parameters of the detection device according to the measurement plan; S4. Adjust the translation and angular position of the six-dimensional adjustment frame according to the interference pattern until the RMS of the optical component to be measured meets the requirements; S5. The vacuum pump evacuates the refrigeration chamber and records the surface shape of the optical component to be tested at room temperature; S6. Liquid nitrogen is passed through the heat sink in the refrigeration chamber to start cooling. After the temperature of the measuring point reaches the target temperature, it is maintained for a preset time. After stabilization, S4 is repeated to record the surface shape of the optical component to be measured under vacuum and low temperature conditions.

5. A low-temperature optical mirror surface detection method according to claim 4, characterized in that: In S3, the position deviation of the detection device is controlled within 0.1 mm, and the angle deviation is controlled within 1′.

6. A low-temperature optical mirror surface detection system according to claim 4, characterized in that: In S6, the cooling rate is 0.3℃ / min, and after the temperature at the measuring point reaches the target temperature, it is maintained for 6 hours.

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