Infrared wavefront test system and method

Abstract

The invention discloses an infrared wavefront testing system and method, and belongs to the field of infrared wavefront testing. Comprising an infrared random background dot matrix, an infrared band-pass filter, an infrared telecentric lens and an infrared detector. The infrared random background dot matrix comprises a temperature control system and a random emissivity background dot matrix. The infrared band-pass filter meets the requirement of a test wave band, so that infrared light waves of a specific wave band enter an infrared imaging system. The infrared telecentric lens eliminates the phase difference of the lenses by using a multi-infrared lens group, so that parallel light enters an infrared detector. The infrared detector is used for capturing infrared radiation signals of the infrared random background dot matrix entering the infrared imaging system, and then infrared random background dot matrix image data before / after flow field disturbance are obtained. On the basis of the background schlieren technology principle, the infrared background dot matrix with random spatial distribution is formed by designing the temperature-controllable and random infrared emissivity background dot matrix, and the wavefront of the infrared band of the variable-refractive-index object is effectively measured in combination with the infrared detector.

Description

Technical Field

[0001] The invention belongs to the field of infrared wavefront testing, and in particular relates to an infrared wavefront testing system and method. Background Art

[0002] When an aircraft flies at hypersonic speed to detect infrared imaging of a target, the infrared light emitted by the target deviates, shakes, and diffuses after passing through the variable-density flow field near the imaging window, which is the aero-optical effect, causing the infrared imaging quality to deteriorate and making it impossible to detect effectively. The reason is that the variable-density flow field near the window causes the wavefront of the infrared light to be distorted, which is the aero-optical distortion wavefront. Therefore, how to effectively measure the aero-optical distortion wavefront in the infrared band becomes the key to experimental research on aero-optical effects, and is also the test technology basis for solving this problem.

[0003] The current infrared wavefront measurement technology is mainly based on the principle of four-wave lateral shearing interferometry, which can realize long-wave, medium-wave and short-wave infrared wavefront measurement. It combines the random coded four-wave diffraction technology with the infrared camera to generate interference at the rear-end image plane position, and combines the interference pattern processing method to realize wavefront information reconstruction.

[0004] The specific principle of four-wave transverse shearing interference is as follows: when the wavefront to be measured passes through the wavefront analyzer (wavefront sensor), the infrared light wave passes through a special grating to obtain a replica beam with a certain transverse displacement from itself. This replica light wave interferes with the light wave to be measured, forming transverse shearing interference, and interference fringes appear at the overlapped part of the two (such as Figure 1 As shown). The measured wavefront may be a plane wave or a converging wave. For plane transverse shear interference, the measured wavefront undergoes a small displacement in its own plane to produce a replica light wave; while for converging transverse shear interference, the replica light wave is produced by the converging wave rotating around its center of curvature. The interference fringes contain differential information of the original wavefront, and the original wavefront can be reproduced through specific analysis and quantitative calculation (inverse Fourier transform) (e.g. Figure 2-3 shown).

[0005] In general, infrared wavefront test equipment, especially medium-wave and long-wave infrared wavefront test, is currently the main solution based on the four-wave lateral shearing interferometry method. This technology brings a great equipment threshold for general laboratories to perform infrared wavefront measurements. At the same time, the above technology relies on a special grating that is integrated at the front end of the detector. The detector is required to have cooling capabilities to prevent the temperature of the detector from increasing and affecting the temperature of the special grating, thereby affecting the accuracy of the infrared wavefront test. The detector system is required to have temperature control (cooling) capabilities, and the equipment is more complex, which leads to higher equipment costs. Summary of the invention

[0006] The present invention proposes a large-scale dynamic detection solution for mini-program vulnerabilities based on policy self-optimization; it aims to solve the technical difficulties that existing mini-program dynamic testing methods are difficult to collect massive mini-programs on a large scale and difficult to perform adaptive testing on large-scale and diverse mini-programs.

[0007] The first aspect of the present invention discloses an infrared wavefront testing system, the system comprising an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein:

[0008] The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material;

[0009] The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system;

[0010] The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector;

[0011] The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance.

[0012] According to the system of the first aspect of the present invention, the first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

[0013] According to the system of the first aspect of the present invention, the infrared band is divided into three bands: short wave, medium wave, and long wave. According to the test band requirements, corresponding short wave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; wherein the short wave wavelength is 0.9 to 1.7 μm, the medium wave wavelength is 3 to 5 μm, and the long wave wavelength is 7 to 14 μm.

[0014] According to the system of the first aspect of the present invention, the infrared telecentric lens adopts an athermal design to reduce the interference of thermal radiation of the lens itself.

[0015] In the system according to the first aspect of the present invention, the configuration of the infrared detector covers the infrared detection of short waves, medium waves and long waves.

[0016] According to the system of the first aspect of the present invention, the system realizes wavefront measurement based on background schlieren; specifically comprising:

[0017] The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path:

[0018]

[0019] Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction;

[0020] Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position:

[0021]

[0022] Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector;

[0023] Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained.

[0024] According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface:

[0025]

[0026] The corresponding OPL result is obtained through integration to complete the wavefront measurement.

[0027] The second aspect of the present invention discloses an infrared wavefront testing method, wherein the method uses an infrared wavefront testing system to implement wavefront measurement based on background schlieren; wherein:

[0028] The system comprises an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein:

[0029] The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material;

[0030] The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system;

[0031] The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector;

[0032] The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance;

[0033] In the method:

[0034] The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path:

[0035]

[0036] Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction;

[0037] Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position:

[0038]

[0039] Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector;

[0040] Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained.

[0041] According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface:

[0042]

[0043] The corresponding OPL result is obtained through integration to complete the wavefront measurement.

[0044] According to the method of the second aspect of the present invention, the first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

[0045] According to the method of the second aspect of the present invention, the infrared band is divided into three bands: short wave, medium wave, and long wave. According to the test band requirements, corresponding short wave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; wherein the short wave wavelength is 0.9 to 1.7 μm, the medium wave wavelength is 3 to 5 μm, and the long wave wavelength is 7 to 14 μm.

[0046] According to the method of the second aspect of the present invention, the infrared telecentric lens adopts an athermal design to reduce the interference of thermal radiation of the lens itself.

[0047] According to the method of the second aspect of the present invention, the configuration of the infrared detector covers short-wave, medium-wave and long-wave infrared detection.

[0048] In summary, the present invention is based on the principle of background schlieren technology. By designing a temperature-controllable, random infrared emissivity background dot matrix, a spatially randomly distributed infrared background dot matrix is ​​formed. Combined with an infrared detector, effective measurement of the infrared band wavefront of a variable refractive index object can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] 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.

[0050] Figure 1 A schematic diagram of geometric optics used in the prior art to describe wavefront distortion;

[0051] Figure 2 It is a schematic diagram of phase reconstruction in the prior art;

[0052] Figure 3 It is a schematic diagram of the wavefront phase reconstruction principle in the prior art;

[0053] Figure 4 It is a schematic diagram of the principle of infrared wavefront testing based on background schlieren according to an embodiment of the present invention;

[0054] Figure 5 Schematic diagram of an infrared random background dot matrix according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0056] The first aspect of the present invention discloses an infrared wavefront testing system, the system comprising an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein:

[0057] The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material;

[0058] The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system;

[0059] The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector;

[0060] The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance.

[0061] According to the system of the first aspect of the present invention, the first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

[0062] According to the system of the first aspect of the present invention, the infrared band is divided into three bands: short wave, medium wave, and long wave. According to the test band requirements, corresponding short wave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; wherein the short wave wavelength is 0.9 to 1.7 μm, the medium wave wavelength is 3 to 5 μm, and the long wave wavelength is 7 to 14 μm.

[0063] According to the system of the first aspect of the present invention, the infrared telecentric lens adopts an athermal design to reduce the interference of thermal radiation of the lens itself.

[0064] According to the system of the first aspect of the present invention, the configuration of the infrared detector covers the infrared detection of short waves, medium waves and long waves.

[0065] According to the system of the first aspect of the present invention, the system realizes wavefront measurement based on background schlieren; specifically comprising:

[0066] The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path:

[0067]

[0068] Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction;

[0069] Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position:

[0070]

[0071] Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector;

[0072] Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained.

[0073] According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface:

[0074]

[0075] The corresponding OPL result is obtained through integration to complete the wavefront measurement.

[0076] First embodiment

[0077] like Figure 4 As shown, the infrared wavefront test system mainly includes four parts: 1-infrared random background dot matrix, 2-infrared bandpass filter, 3-infrared telecentric lens, and 4-infrared detector.

[0078] The following is a detailed introduction to each component of the background schlieren infrared wavefront testing technology:

[0079] 1-Infrared random background dot matrix

[0080] like Figure 5The figure shows the infrared random background dot matrix used in this technology, which is mainly composed of a temperature control system and a random emissivity background dot matrix. The temperature control system uses a high-density resistance wire heating method to achieve specific temperature (T) control of the infrared random background dot matrix. The random emissivity background dot matrix is ​​mainly achieved by printing a high infrared emissivity (ε2≈0.9) layer on the surface of low infrared emissivity (ε1≈0.05) materials such as polished aluminum alloy and mirror stainless steel, corresponding to Figure 5 To ensure that the infrared imaging system can obtain the results reflecting the random distribution intensity of infrared radiation space.

[0081] 2-Infrared bandpass filter

[0082] The infrared band is mainly divided into three typical bands: shortwave (0.9-1.7μm), medium wave (3-5μm), and long wave (7-14μm). According to the test band requirements, corresponding shortwave, medium wave, and long wave bandpass filters are selected to ensure that infrared light waves in specific bands enter the infrared imaging system.

[0083] 3-Infrared telecentric lens

[0084] Adopt telecentric optical path design. Figure 4 The red frame in the middle is a schematic diagram of the principle. The specific implementation requires multiple infrared lens groups to eliminate the influence of the lens' own phase difference. The infrared telecentric lens can ensure that only parallel light can enter the detector, improving the accuracy of wavefront measurement. At the same time, the athermal design is adopted to reduce the interference of the lens' own thermal radiation.

[0085] 4-Infrared detector

[0086] The infrared detector is mainly used to capture the infrared radiation signal of the random background dot matrix entering the telecentric imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance. The present invention has no additional requirements for the infrared detector, and conventional short-wave, medium-wave, and long-wave infrared detectors are all supported.

[0087] The second aspect of the present invention discloses an infrared wavefront testing method, wherein the method uses an infrared wavefront testing system to implement wavefront measurement based on background schlieren; wherein:

[0088] The system comprises an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein:

[0089] The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material;

[0090] The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system;

[0091] The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector;

[0092] The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance;

[0093] In the method:

[0094] The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path:

[0095]

[0096] Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction;

[0097] Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position:

[0098]

[0099] Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector;

[0100] Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained.

[0101] According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface:

[0102]

[0103] The corresponding OPL result is obtained through integration to complete the wavefront measurement.

[0104] According to the method of the second aspect of the present invention, the first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

[0105] According to the method of the second aspect of the present invention, the infrared band is divided into three bands: short wave, medium wave, and long wave. According to the test band requirements, corresponding short wave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; wherein the short wave wavelength is 0.9 to 1.7 μm, the medium wave wavelength is 3 to 5 μm, and the long wave wavelength is 7 to 14 μm.

[0106] According to the method of the second aspect of the present invention, the infrared telecentric lens adopts an athermal design to reduce the interference of thermal radiation of the lens itself.

[0107] According to the method of the second aspect of the present invention, the configuration of the infrared detector covers short-wave, medium-wave and long-wave infrared detection.

[0108] Second embodiment

[0109] The infrared wavefront test method realizes wavefront measurement based on background schlieren; specifically includes:

[0110] Wavefront is generally expressed in terms of optical path length (OPL). OPL can be obtained by integrating the refractive index n along the light propagation path, i.e.

[0111]

[0112] like Figure 5 As shown in FIG. 1 , by performing cross-correlation calculation on a pair of infrared random background dot patterns obtained with and without optical distortion, the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position can be obtained. According to simple geometric relationships, such as Figure 4 As shown, combined with formula (2), we can get:

[0113]

[0114] Equation (2) essentially constructs the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm. It should be noted that the displacement data obtained here is not the displacement result of a single spot, but the common characterization of the displacement structure of a large number of spots in the interrogation window. However, because the interrogation window size used is very small, a relatively high spatial resolution can still be obtained.

[0115] According to Huygens' principle, we know that the wavefront propagation direction is always along the normal direction of the local wavefront surface, that is:

[0116]

[0117] By selecting a suitable integration method, such as the Southwell method, the gradient integration algorithm can use formula (3) to reconstruct the wavefront, obtain the corresponding OPL result, and complete the wavefront measurement. The negative sign in formula (3) is mainly determined by the optical path arrangement and can be explained by the pinhole imaging principle.

[0118] In summary, the present invention is based on the principle of background schlieren technology. By designing a temperature-controllable, random infrared emissivity background dot matrix, a spatially randomly distributed infrared background dot matrix is ​​formed. Combined with an infrared detector, effective measurement of the infrared band wavefront of a variable refractive index object can be achieved.

[0119] The present invention is based on a specially designed infrared random background dot matrix, utilizes the wavefront measurement principle based on background schlieren, combines spectral selection, dual telecentric optical path and infrared detector to achieve high-precision infrared band aero-optical distortion wavefront test. The present invention designs a temperature-controllable infrared random background dot matrix technology based on infrared emissivity differences. The present invention utilizes a telecentric optical path to improve the accuracy of infrared wavefront test based on background schlieren.

[0120] The present invention does not need to use a special grating, which significantly reduces the cost of the test solution. The present invention does not need an additional infrared collimated light source and corresponding alignment adjustment, and is easy to use. The special grating in the prior art is relatively close to the detector and is easily affected by the heating of the detector. It is necessary to consider the heat reduction requirements of the special grating. The present invention does not need additional cooling measures, which further reduces the implementation cost.

[0121] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-mentioned embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. An infrared wavefront testing system, characterized in that: The system comprises an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein: The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material; The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system; The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector; The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance.

2. An infrared wavefront testing system according to claim 1, characterized in that: The first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

3. An infrared wavefront testing system according to claim 2, characterized in that: The infrared band is divided into three bands: shortwave, medium wave, and long wave. According to the test band requirements, the corresponding shortwave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; among them, the shortwave wavelength is 0.9~1.7μm, the medium wave wavelength is 3~5μm, and the long wave wavelength is 7~14μm.

4. The infrared wavefront testing system according to claim 3, characterized in that: The infrared telecentric lens adopts an athermal design to reduce the interference of the lens' own thermal radiation.

5. The infrared wavefront testing system according to claim 4, characterized in that: The configuration of infrared detectors covers short-wave, medium-wave and long-wave infrared detection.

6. The infrared wavefront testing system according to claim 5, characterized in that: The system realizes wavefront measurement based on background schlieren; specifically includes: The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path: Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction; Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position: Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector; Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained. According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface: The corresponding OPL result is obtained through integration to complete the wavefront measurement.

7. An infrared wavefront testing method, characterized in that: The method uses an infrared wavefront test system to achieve wavefront measurement based on background schlieren; wherein: The system comprises an infrared random background dot matrix, an infrared bandpass filter, an infrared telecentric lens and an infrared detector; wherein: The infrared random background dot matrix includes a temperature control system and a random emissivity background dot matrix; the temperature control system controls the infrared random background dot matrix at a specific temperature by means of high-density resistance wire heating; the random emissivity background dot matrix enables the infrared imaging system to capture the random distribution intensity of infrared radiation space by printing a second infrared emissivity layer on the surface of the first infrared emissivity material; The infrared bandpass filter meets the test band requirements, allowing infrared light waves in a specific band to enter the infrared imaging system; The infrared telecentric lens adopts a telecentric optical path design and uses a multi-infrared lens group to eliminate the influence of the lens' own phase difference, allowing parallel light to enter the infrared detector; The infrared detector is used to capture the infrared radiation signal of the infrared random background dot matrix entering the infrared imaging system, and then obtain the infrared random background dot matrix image data before / after the flow field disturbance; In the method: The wavefront is represented by the optical path OPL, which is obtained by integrating the refractive index n along the light propagation path: Wherein, z is the main optical axis of light propagation, z0 is the starting position of light transmission, and W is the flow field width along the z direction; Based on a pair of infrared random background dot patterns obtained with and without optical distortion, cross-correlation calculation is performed to obtain the light offset (Δx, Δy) caused by the optical distortion corresponding to the corresponding interrogation window position: Among them, θ x Represents the deflection angle of the light relative to the x-axis, θ y It represents the deflection angle of light relative to the y-axis, and L represents the distance between the image lens of the telecentric imaging system and the target surface of the infrared detector; Thus, the relationship between the deflection angle of the light and the displacement data obtained by the cross-correlation algorithm is constructed. The displacement data is not the offset result of a single light spot, but the common characterization of the displacement structure of a large number of light spots in the interrogation window. The smaller the interrogation window size, the higher the spatial resolution obtained. According to Huygens' principle, the wavefront propagation direction is along the normal direction of the local wavefront surface: The corresponding OPL result is obtained through integration to complete the wavefront measurement.

8. An infrared wavefront testing method according to claim 7, characterized in that: The first infrared emissivity is 0.05, the second infrared emissivity is 0.9, and the material of the first infrared emissivity is polished aluminum alloy or mirror stainless steel.

9. The infrared wavefront testing method according to claim 8, characterized in that: The infrared band is divided into three bands: shortwave, medium wave, and long wave. According to the test band requirements, the corresponding shortwave, medium wave, and long wave infrared bandpass filters are selected to allow infrared light waves in a specific band to enter the infrared imaging system; among them, the shortwave wavelength is 0.9~1.7μm, the medium wave wavelength is 3~5μm, and the long wave wavelength is 7~14μm.

10. An infrared wavefront testing method according to claim 9, characterized in that: The infrared telecentric lens adopts an athermal design to reduce the interference of the lens's own thermal radiation; the configuration of the infrared detector covers short-wave, medium-wave and long-wave infrared detection.

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