Deformable mirror performance simulation detection method

Abstract

The invention relates to a deformable mirror performance simulation detection method, which comprises the steps of decomposing a complex distorted wavefront and solving a control matrix of a deformable mirror, and finally obtaining a surface type function of the deformable mirror; according to the surface type function of the deformable mirror, obtaining the intersection point of the emergent light and the surface of the deformable mirror based on the optical tracing of the image; the light is subjected to mirror reflection at the intersection point, the radiation exitance of the light reflected on the mirror and the irradiance of the light finally reaching the image surface are calculated based on a bidirectional reflection distribution function, and a simulation distortion image obtained after the wavefront of the light emitted by the actual object is modulated by the deformable mirror is obtained; and comparing the calculated simulation distortion image with the ideal distortion image, and evaluating the performance of the deformable mirror. According to the method, the design and optimization of the deformable mirror can be effectively assisted, and waste caused by design errors is avoided.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a method for simulating and detecting the performance of a deformable mirror. Background Art

[0002] A deformable mirror is a device that changes the phase of light wave transmission by changing the shape of the mirror surface. As a wavefront correction device, it is widely used in various adaptive optical systems. Because it can change the wavefront phase of the incident light, it is also used to simulate and restore various distorted wavefronts.

[0003] The deformable mirror is deformed under the coupling of the driver and the mirror surface. Its wavefront phase modulation is in the micrometer or even nanometer level, so there are high requirements for the number, arrangement and mirror material of the driver of the deformable mirror.

[0004] The mirror surface of the deformable mirror is mostly made of metal film, mostly aluminum or silver, which has its own reflectivity, and the mirror surface itself will also produce diffuse reflection, so not all light will enter the camera system. And when the surface of the deformable mirror is deformed, the surface becomes irregular, causing the mirror reflection to scatter in different directions. The amount of diffuse reflection that occurs depends on the degree and nature of the deformation, the incident angle of the light, and the characteristics of the mirror coating. If the deformation is large, it will cause a lot of diffuse reflection, resulting in a decrease in image quality. There will be changes in brightness and blur between the actual imaging and the ideal imaging. Therefore, the actual imaging performance of the deformable mirror is different from the theoretical performance.

[0005] When the deformable mirror compensates for the aberration caused by the dynamic high-frequency random dynamic medium, since the bandwidth of the deformable mirror is much smaller than the frequency aberration of the random dynamic medium, there will be a considerable error when the deformable mirror compensates for the aberration caused by the random dynamic medium. By building an optical path and using experimental equipment such as a wavefront sensor, this error of the deformable mirror can be measured. However, the material of the deformable mirror itself is expensive. If it is measured after the deformable mirror is prepared, when the error exceeds the acceptable range, it will be very expensive to adjust and replace the deformable mirror. When experimentally testing the dynamic performance of the deformable mirror, it is necessary to insert a high-frequency random dynamic medium into the experimental optical path. Currently known experimental simulation methods of high-frequency random dynamic media include wind tunnels, flight experiments, etc. These experimental methods are very expensive and cannot last for a long time. Therefore, it is necessary to use simulation methods to estimate and measure this error of the deformable mirror. Summary of the invention

[0006] In view of this, it is necessary to provide a deformable mirror performance simulation detection method, which can effectively assist the deformable mirror design and optimization and avoid waste caused by design errors.

[0007] The present invention provides a deformable mirror performance simulation detection method, the method comprising the following steps:

[0008] S1. Decompose the complex distorted wavefront and solve the control matrix of the deformable mirror, and finally obtain the surface function of the deformable mirror;

[0009] S2. According to the surface function of the deformable mirror, based on the optical tracing of the image, the intersection point of the outgoing light and the surface of the deformable mirror is obtained;

[0010] S3. The light is reflected by a mirror at the intersection, and the radiant emittance of the light reflected by the mirror and the irradiance finally reaching the image plane are calculated based on the bidirectional reflectance distribution function to obtain a simulated distorted image of the wavefront of the light emitted by the actual object after being modulated by the deformable mirror;

[0011] S4. Compare the calculated simulated distortion image with the ideal distortion image to evaluate the performance of the deformable mirror.

[0012] Preferably, the decomposing a complex distorted wavefront comprises:

[0013] In the wavefront decomposition of light, the wavefront is divided into several small areas. The wavefront in each small area is expressed by expanding several one-dimensional Zernike polynomials. Then, the expansion coefficients are used to construct a set of algebraic equations for the entire wavefront, and the distribution of the entire wavefront is obtained by solving them.

[0014] Preferably, the step S1 comprises:

[0015] Use the super-Gaussian function to establish the influence function f between any actuator and the mirror surface shape change j Mathematical description of (x,y):

[0016]

[0017] Where ω is the cross-link value between the actuators, α is the Gaussian exponent, and x j ,y j is the coordinate of the jth actuator, d is the spacing between actuators;

[0018] The control matrix C of the deformable mirror actuator is obtained j :

[0019] C j =T(f j ,a j ) (3)

[0020] Where T is the calculation function of the control matrix;

[0021] The control matrix C j The discrete surface shape of the deformable mirror is input into the simulation software to obtain the deformed surface shape, which is then fitted through a neural network to obtain the surface shape function S (x, y, z) of the deformable mirror.

[0022] Preferably, the intersection points include: the intersection points of light rays and the deformable mirror in a uniform static medium, and the dynamic intersection points of light rays and the deformable mirror surface in an interval between two deformations of the deformable mirror in a random dynamic medium.

[0023] Preferably, the step S2 comprises:

[0024] Step S2-1: performing optical tracing in a static state after deformation of the deformable mirror, compressing the three-dimensional object into a two-dimensional plane to simulate the light emitted by the target object, and combining the expression of the light ray with the surface function of the deformable mirror to obtain the intersection point of the light ray and the deformable mirror in the uniform static medium;

[0025] Step S2-2: insert a high-frequency random dynamic medium between the deformable mirror and the image, and obtain the dynamic intersection of the light ray in the random dynamic medium and the deformable mirror surface within the interval between two deformations of the deformable mirror.

[0026] Preferably, the step S2-1 comprises:

[0027] The three-dimensional object is compressed into a two-dimensional plane to simulate the light emitted by the target object. After passing through the collimation system, the light is incident on the deformable mirror as parallel light.

[0028] Object(x,y,z)→Image(x,y) (4)

[0029] Where Object(x,y,z) is a three-dimensional object; Image(x,y) is a two-dimensional image;

[0030] I m =Image(x,y)×Mask (5)

[0031] Where Mask is a mask with the same shape as the deformable mirror, I m is an image with the same shape as the deformable mirror;

[0032] Using the known size of the deformable mirror, each pixel is given an actual spatial scale, so that the three-dimensional object has an actual two-dimensional scale; assuming that the area of ​​the deformable mirror is S, the size of the pixel in the physical scale is:

[0033]

[0034] In the formula, l pixel is the side length of the square pixel; N is the number of pixels in the circular image;

[0035] Then, the second-order pixel domain is introduced, and each pixel is divided into N equal parts according to the actual two-dimensional scale. The center position of each second-order pixel is used as the starting position to draw parallel rays to simulate the "light" emitted by the object. In this way, each pixel will have N "light rays" emitted:

[0036] O(x,y,0)=I m (x·l pixel ,y·l pixel ) (7)

[0037] In the formula, O(x,y,0) is the initial position of the “light” on the image;

[0038] "Light" propagates along a straight line in a homogeneous medium, and the expression of the "light" ray L(x,y,z) is obtained:

[0039]

[0040] In the formula, O x , O y , O z are the coordinates of the starting point of the “light” on the image; a, b, c are the direction vectors of the “light”;

[0041] The expression of the light ray is combined with the surface function S(x,y,z) of the deformable mirror obtained by S1 to directly find the intersection point P(x P ,y P ,z P ).

[0042] Preferably, the step S2-2 comprises:

[0043] The inhomogeneous discrete density field of the random dynamic medium is obtained through numerical simulation; the density field is then converted into a refractive index field and interpolated; the numerical solution of the optical path is calculated by solving the ray equation; finally, ray tracing in the inhomogeneous medium is achieved; the ray equation is as follows:

[0044]

[0045] In the formula, is the light path; n is the refractive index in the inhomogeneous medium;

[0046] Among them, the discrete density field interpolation methods include: inverse distance weighted interpolation method, cubic spline interpolation method, linear interpolation method, and nearest neighbor interpolation method.

[0047] Preferably, the step S3 comprises:

[0048] According to the RGB value carried by the "light", recalculate the radiance reflected by each "light" in different directions; when calculating the irradiance of each pixel, calculate the average irradiance of the "light" that falls within the physical scale of the pixel:

[0049]

[0050] Where e is the irradiance of the solid angle of a single "light"; N i is the number of “rays” that fall within the pixel;

[0051] At this point, a simulated distorted image is obtained after the wavefront of the light emitted by the actual object is modulated by the deformable mirror.

[0052] Preferably, the step S4 comprises:

[0053] Based on the known distorted wavefront, the point spread function is calculated, and the original image is convolved with the point spread function to obtain the ideal distorted image.

[0054] Preferably, the step S4 further comprises:

[0055] When evaluating the static performance of the deformable mirror, the mean square error, peak signal-to-noise ratio and structural similarity evaluation indicators are selected:

[0056] When evaluating the dynamic performance of the deformable mirror, the dynamic absolute value is introduced. The dynamic absolute value integrates the difference between the SSIM values ​​of the simulated distorted image and the ideal distorted image within the deformation interval of the deformable mirror over time. DAV intuitively reflects the dynamic performance of the deformable mirror:

[0057]

[0058] Where BD is the bandwidth of the deformable mirror, SSIM simulation is the continuous SSIM of the simulated distorted image, SSIM random It is a high-frequency dynamic distortion image caused by high-frequency random dynamic medium;

[0059] The ideal distorted image and the tracked distorted image are compared and analyzed by means of mean square error, peak signal-to-noise ratio, structural similarity and dynamic absolute value to obtain the performance of the deformable mirror for wavefront reproduction under the current number, arrangement and mirror material of the actuators. At the same time, the influence of different incident angles on the imaging performance of the deformable mirror is also evaluated through the changes in the above parameters.

[0060] The present invention can simulate the performance of deformable mirrors with different actuator arrangements, different mirror materials, and different structures. The main innovations of the present invention include:

[0061] First, starting from the image, the tracing simulation of the image modulated by the deformable mirror is carried out. The simulation includes the diffuse reflection caused by the deformed mirror surface and the influence of the deformable mirror surface material on the light reflection, making the simulation closer to the reality;

[0062] Secondly, the dynamic performance of the deformable mirror is tested based on the simulated high-frequency random dynamic medium. The dynamic absolute value (DAV) is proposed to evaluate the dynamic performance of the deformable mirror.

[0063] The present invention can accurately evaluate the actual optical performance and imaging performance of the deformable mirror in the design stage. During the ray tracing process, the emission direction of the light source can be arbitrarily changed to test the optimal use angle of the deformable mirror. The present invention can effectively assist the design and optimization of the deformable mirror and avoid waste caused by design errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of the method for simulation detection of deformable mirror performance of the present invention;

[0065] Figure 2 A schematic diagram of the decomposition of the distorted wavefront Zernike polynomial provided in an embodiment of the present invention;

[0066] Figure 3 A schematic diagram of a deformation mirror type simulation result provided by an embodiment of the present invention;

[0067] Figure 4 A schematic diagram of an implementation environment of an embodiment of the present invention. DETAILED DESCRIPTION

[0068] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0069] See also Figure 1 The figure shows the operation flow chart of a preferred embodiment of the deformable mirror performance simulation detection method of the present invention.

[0070] The present invention specifically includes:

[0071] Step S1, decomposing the complex distorted wavefront and solving the control matrix of the deformable mirror, and finally obtaining the surface function of the deformable mirror.

[0072] When decomposing complex distorted wavefronts, please also refer to Figure 2 , use Zernike polynomials to decompose the wavefront into expansion coefficients in each small area. In this way, the linear properties of the optical system can be used to perform efficient numerical calculations on light and achieve high-precision image field simulation. Specifically, in the wavefront decomposition of light, the wavefront is divided into several small areas, and the wavefront in each small area is represented by several one-dimensional Zernike polynomial expansions. That is, the phase of each point on the wavefront is expanded into a linear combination of Zernike polynomials of different orders. Then, using the expansion coefficients, a group of algebraic equations for the entire wavefront is constructed, and the distribution of the entire wavefront is obtained by solving it.

[0073] Zernike polynomial decomposition technology is of great significance for applications such as high-precision imaging and phase shift measurement of optical systems, and can improve the stability and performance of the system.

[0074] If the first J-order Zernike polynomials are used to describe the distorted wavefront W z (ρ,θ), then it can be expressed as:

[0075]

[0076] Where: a j is the jth order Zernike polynomial Z j The coefficients of (ρ,θ).

[0077] After obtaining the coefficients of the Zernike polynomials, the control variables of each actuator of the deformable mirror, namely the control matrix, are solved.

[0078] When the actuator is acted upon by a driving voltage, the deformable mirror will deform. In order to describe the distribution of deformation on the mirror surface, a concept called "influence function" is introduced. The influence function describes the distribution of local deformation caused by the actuator on the mirror surface under different voltages.

[0079] Use the super-Gaussian function to establish the influence function f between any actuator and the mirror surface shape change j Mathematical description of (x,y):

[0080]

[0081] Where ω is the cross-link value between the actuators, α is the Gaussian exponent, and x j ,y j is the coordinate of the jth actuator, and d is the spacing between actuators.

[0082] The control matrix C of the deformable mirror actuator is obtained j :

[0083] C j =T(f j ,a j ) (3)

[0084] Where T is the calculation function of the control matrix.

[0085] The control matrix C j After inputting into the simulation software Comsol, the discrete surface shape of the deformable mirror is obtained. The surface shape function S(x, y, z) of the deformable mirror is obtained by fitting it through a neural network.

[0086] Among them, the neural network includes: BP neural network, LSTM neural network, etc.

[0087] Step S2, according to the obtained deformable mirror surface function, based on the optical tracing of the image, obtain the intersection point of the outgoing light and the deformable mirror surface. The intersection point includes: the intersection point of the light ray and the deformable mirror in a uniform static medium, and the dynamic intersection point of the light ray and the deformable mirror surface in a random dynamic medium within the interval between two deformations of the deformable mirror.

[0088] Specifically include:

[0089] Step S2-1: Perform optical tracing in a stationary state after deformation of the deformable mirror, compress the three-dimensional object into a two-dimensional plane to simulate the light emitted by the target object, and combine the expression of the light ray with the surface function of the deformable mirror to obtain the intersection of the light ray and the deformable mirror in the uniform static medium.

[0090] Unlike traditional optical tracing, the optical tracing of this application starts from the target image. Because any three-dimensional object is a two-dimensional image in the image, this application compresses the three-dimensional object into a two-dimensional plane to simulate the light emitted by the target object, and after passing through the collimation system, it is incident on the deformable mirror as parallel light.

[0091] Object(x,y,z)→Image(x,y) (4)

[0092] Where Object(x,y,z) is a three-dimensional object; Image(x,y) is a two-dimensional image.

[0093] I m =Image(x,y)×Mask (5)

[0094] Where Mask is a mask with the same shape as the deformable mirror, I m is an image with the same shape as the deformable mirror.

[0095] Therefore, before performing optical tracking, the relative relationship between the target object and the deformable mirror size must be determined. Using the known size of the deformable mirror, each pixel is given an actual spatial scale, so that the three-dimensional object has an actual two-dimensional scale. Assuming that the area of ​​the deformable mirror is S, the size of the pixel in the physical scale is:

[0096]

[0097] In the formula, l pixel is the side length of the square pixel; N is the number of pixels in the circular image.

[0098] Then, the second-order pixel domain is introduced, and each pixel is divided into N equal parts according to the actual two-dimensional scale. The parallel rays are drawn from the center position of each second-order pixel as the starting position to simulate the "light" emitted by the object. In this way, each pixel will have N "light rays" emitted.

[0099] O(x,y,0)=I m (x·l pixel ,y·l pixel ) (7)

[0100] Where O(x,y,0) is the initial position of the “light” on the image.

[0101] "Light" propagates in a straight line in a homogeneous medium. In this case, the expression of the "light" ray L(x,y,z) is obtained:

[0102]

[0103] In the formula, O x , O y , O z are the coordinates of the starting point of the “light” on the image; a, b, c are the direction vectors of the “light”.

[0104] By combining the expression of the light ray with the surface function S(x,y,z) of the deformable mirror obtained by S1, we can directly find the intersection point P(x P ,y P ,z P ).

[0105]

[0106] Step S2-2: insert a high-frequency random dynamic medium between the deformable mirror and the image, and obtain the dynamic intersection of the light ray in the random dynamic medium and the deformable mirror surface within the interval between two deformations of the deformable mirror.

[0107] In most cases, the use environment of the deformable mirror is not stable, and the propagation medium of light is mainly random dynamic medium. Therefore, finite element analysis is introduced to obtain the inhomogeneous discrete density field of the random dynamic medium through numerical simulation; then the density field is converted into a refractive index field and interpolated; the numerical solution of the optical path is calculated by solving the light equation. Finally, ray tracing in inhomogeneous media is achieved. The light equation is as follows:

[0108]

[0109] In the formula, is the light path; n is the refractive index in the inhomogeneous medium.

[0110] Among them, the interpolation methods for discrete density fields include: inverse distance weighted interpolation, cubic spline interpolation, linear interpolation, nearest neighbor interpolation, etc.

[0111] At the same time, due to the limitation of the deformable mirror control bandwidth BD, the dynamic performance of the deformable mirror when reproducing the distorted wavefront will also have a great impact on dynamic imaging. When optically tracing from the two-dimensional image to the deformable mirror surface, random dynamic media of different frequencies are inserted between the two-dimensional plane and the deformable mirror, and the dynamic performance of the deformable mirror and the reproduction performance of the existing bandwidth for the distorted wavefront at different frequencies are evaluated through the tracing results.

[0112] Step S3, the light is reflected by a mirror at the intersection, and based on the bidirectional reflectance distribution function (BRDF), the radiance of the light reflected by the mirror and the irradiance finally reaching the image plane are calculated to obtain a simulated distorted image of the wavefront of the light emitted by the actual object after being modulated by the deformable mirror. Specifically:

[0113] The "light" collides with the mirror surface and is reflected on the surface. For the intersection point P of the light obtained by S2 and the deformable mirror, the incident angle of the "light" is ω i , the exit angle is ω o , then ω i =ω o . Most "light" produces specular reflection on the mirror surface, but a small amount of "light" will be absorbed by the mirror surface and will have a certain transmittance. By combining various light losses, the comprehensive reflectivity of the light is obtained. Here we introduce the bidirectional reflectance distribution function (BRDF). BRDF is a function that describes the distribution of light reflected from the surface of a material. BRDF is used to describe the distribution of reverse light in the outgoing direction at a point, and its reflectivity is related to the incident direction, reflection direction, surface normal direction, etc. Normally, BRDF represents the differential reflectivity at a certain point. The differential reflectivity is a function of the outgoing direction and the incident direction, and is usually used to describe how the incident light at a certain point is distributed to the intensity in each outgoing direction. BRDF is widely used and is often used in the distribution of light on the surface of reflective objects in fields such as computer graphics and computer vision. BRDF provides a physical law that describes the reflection of light from the surface of an object.

[0114] This embodiment provides a BRDF function f for specular reflection: cook-torrance :

[0115]

[0116] Where v is the reflection direction (observation direction); l is the incident direction; n fis the macro surface normal; h is the micro plane normal; D(h) is the Normal Distribution Function, which represents the distribution of tiny mirror normals at all microscopic angles. The normal distribution of rough surfaces is relatively uniform, and the normal distribution of smooth surfaces is relatively concentrated; F(l,h) is the Fresnel Equation, which describes the ratio of light reflected from the surface of an object at different incident light angles; G(l,v) is the Geometry Function, which describes the self-occlusion property of micro planes. When a plane is relatively rough, the micro planes on the plane surface may block other micro planes, thereby reducing the light reflected by the surface.

[0117] According to the RGB value carried by the "light", the radiant emittance of each "light" reflected in different directions is recalculated. When the deformable mirror is deformed to a large extent, the "light" will be diffusely reflected after the mirror reflection. Therefore, some "light" will not eventually fall on the image plane, so the number of "light" is likely to be reduced when the image is finally formed. When calculating the irradiance of each pixel, the average irradiance of the "light" falling within the physical scale of the pixel is calculated:

[0118]

[0119] Where e is the irradiance of the solid angle of a single "light"; N i is the number of "rays" that fall within that pixel.

[0120] See also Figure 3 At this point, a simulated distorted image is obtained after the wavefront of the light emitted by the actual object is modulated by the deformable mirror.

[0121] Step S4, comparing the calculated simulated distortion image with the ideal distortion image to evaluate the performance of the deformable mirror. Specifically:

[0122] Based on the known distorted wavefront, the point spread function (PSF) is calculated, and the original image is convolved with the point spread function to obtain the ideal distorted image.

[0123] The ability of the deformable mirror to reproduce a fixed distorted wavefront is evaluated by comparing the simulated distorted image and the ideal distorted image obtained by optical tracing in a uniform medium. That is, the quality of the simulated distorted image modulated by the deformable mirror is compared with the quality of the ideal distorted image.

[0124] The dynamic performance of the deformable mirror and its dynamic compensation capability for wavefront distortion are evaluated by comparing the simulated distorted image and the ideal distorted image obtained by optical tracing in random dynamic media. That is, the quality of the simulated distorted image modulated by the deformable mirror and the quality of the ideal distorted image affected by high-frequency random dynamic media are compared between the two deformations of the deformable mirror.

[0125] When evaluating the static performance of the deformable mirror, evaluation indicators such as mean square error (MSE), peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) can be selected.

[0126] When evaluating the dynamic performance of the deformable mirror, the dynamic absolute value (DAV) is introduced. DAV integrates the difference between the SSIM values ​​of the simulated distorted image and the ideal distorted image within the deformation interval of the deformable mirror over time. DAV intuitively reflects the dynamic performance of the deformable mirror:

[0127]

[0128] Where BD is the bandwidth of the deformable mirror, SSIM simulation is the continuous SSIM of the simulated distorted image, SSIM random It is a high-frequency dynamic distortion image caused by high-frequency random dynamic medium.

[0129] The ideal distorted image and the tracked distorted image are compared and analyzed through parameters such as mean square error (MSE), peak signal-to-noise ratio (PSNR), structural similarity (SSIM) and dynamic absolute value (DAV), so as to obtain the performance of the deformable mirror for wavefront reproduction under the current number, arrangement and mirror material of the actuators. At the same time, the influence of different incident angles on the imaging performance of the deformable mirror is also evaluated through the changes in these three parameters.

[0130] The present invention truly simulates the process of physical imaging based on an algorithm of optical tracing, and evaluates the static wavefront reproduction performance of the deformable mirror by comparing the difference between the static simulated distorted image modulated by the deformable mirror and the ideal distorted image. A non-uniform random dynamic medium is inserted between the deformable mirror and the object, and the dynamic wavefront reproduction performance of the deformable mirror is evaluated by comparing the difference between the dynamic simulated distorted image modulated by the deformable mirror and the ideal distorted image between two deformations of the deformable mirror. The present invention can provide a reference for the design of the deformable mirror.

[0131] Although the present invention has been described with reference to the current preferred embodiments, those skilled in the art should understand that the above-mentioned preferred embodiments are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for simulation detection of deformable mirror performance, characterized in that: The method comprises the following steps: S1. Decompose the complex distorted wavefront and solve the control matrix of the deformable mirror, and finally obtain the surface function of the deformable mirror; S2. According to the surface function of the deformable mirror, based on the optical tracing of the image, the intersection of the outgoing light and the surface of the deformable mirror is obtained; S3. The light is reflected by a mirror at the intersection, and the radiant emittance of the light reflected by the mirror and the irradiance finally reaching the image plane are calculated based on the bidirectional reflectance distribution function to obtain a simulated distorted image of the wavefront of the light emitted by the actual object after being modulated by the deformable mirror; S4. Compare the calculated simulated distortion image with the ideal distortion image to evaluate the performance of the deformable mirror.

2. The deformable mirror performance simulation detection method according to claim 1, characterized in that: The decomposition of the complex distorted wavefront includes: In the wavefront decomposition of light, the wavefront is divided into several small areas. The wavefront in each small area is expressed by several one-dimensional Zernike polynomial expansions. Then, the expansion coefficients are used to construct a set of algebraic equations for the entire wavefront, and the distribution of the entire wavefront is obtained by solving them.

3. The deformable mirror performance simulation detection method according to claim 2, characterized in that: The step S1 comprises: Use the super-Gaussian function to establish the influence function f between any actuator and the mirror surface shape change j Mathematical description of (x,y): Where ω is the cross-link value between the actuators, α is the Gaussian exponent, and x j ,y j is the coordinate of the jth actuator, d is the spacing between actuators; The control matrix C of the deformable mirror actuator is obtained j : C j =T(f j ,a j ) (3) Where T is the calculation function of the control matrix; The control matrix C j The discrete surface shape of the deformable mirror is input into the simulation software to obtain the deformed surface shape, which is then fitted through a neural network to obtain the surface shape function S (x, y, z) of the deformable mirror.

4. The method for simulation detection of deformable mirror performance according to claim 3, characterized in that: The intersection points include: the intersection points of light rays and the deformable mirror in a uniform static medium, and the dynamic intersection points of light rays and the deformable mirror surface in a random dynamic medium within an interval between two deformations of the deformable mirror.

5. The deformable mirror performance simulation detection method according to claim 4, characterized in that: The step S2 comprises: Step S2-1: performing optical tracing in a static state after deformation of the deformable mirror, compressing the three-dimensional object into a two-dimensional plane to simulate the light emitted by the target object, and combining the expression of the light ray with the surface function of the deformable mirror to obtain the intersection point of the light ray and the deformable mirror in the uniform static medium; Step S2-2: insert a high-frequency random dynamic medium between the deformable mirror and the image, and obtain the dynamic intersection of the light ray in the random dynamic medium and the deformable mirror surface within the interval between two deformations of the deformable mirror.

6. The method for simulation detection of deformable mirror performance according to claim 5, characterized in that: The step S2-1 comprises: The three-dimensional object is compressed into a two-dimensional plane to simulate the light emitted by the target object. After passing through the collimation system, the light is incident on the deformable mirror as parallel light. Object(x,y,z)→Image(x,y) (4) Where Object(x,y,z) is a three-dimensional object; Image(x,y) is a two-dimensional image; I m =Image(x,y)×Mask (5) Where Mask is a mask with the same shape as the deformable mirror, I m is an image with the same shape as the deformable mirror; Using the known size of the deformable mirror, each pixel is given an actual spatial scale, so that the three-dimensional object has an actual two-dimensional scale; assuming that the area of ​​the deformable mirror is S, the size of the pixel in the physical scale is: In the formula, l pixel is the side length of the square pixel; N is the number of pixels in the circular image; Then, the second-order pixel domain is introduced, and each pixel is divided into N equal parts according to the actual two-dimensional scale. The center position of each second-order pixel is used as the starting position to draw parallel rays to simulate the "light" emitted by the object. In this way, each pixel will have N "light rays" emitted: O(x,y,0)=I m (x·l pixel ,y·l pixel ) (7) In the formula, O(x,y,0) is the initial position of the "light" on the image; "Light" propagates along a straight line in a homogeneous medium, and the expression of the "light" ray L(x,y,z) is obtained: In the formula, O x , O y , O z are the coordinates of the starting point of the "light" on the image; a, b, c are the direction vectors of the "light"; Combine the expression of the light ray with the surface function S(x,y,z) of the deformable mirror obtained by S1 to directly find the intersection point P(x P ,y P ,z P ).

7. The method for simulation detection of deformable mirror performance according to claim 6, characterized in that: The step S2-2 comprises: The inhomogeneous discrete density field of the random dynamic medium is obtained through numerical simulation; the density field is then converted into a refractive index field and interpolated; the numerical solution of the optical path is calculated by solving the ray equation; finally, ray tracing in the inhomogeneous medium is achieved; the ray equation is as follows: In the formula, is the light path; n is the refractive index in the inhomogeneous medium; Among them, the discrete density field interpolation methods include: inverse distance weighted interpolation method, cubic spline interpolation method, linear interpolation method, and nearest neighbor interpolation method.

8. The method for simulation detection of deformable mirror performance according to claim 7, characterized in that: The step S3 comprises: According to the RGB value carried by the "light", recalculate the radiant emittance reflected by each "light" in different directions; when calculating the irradiance of each pixel, calculate the average irradiance of the "light" that falls within the physical scale of the pixel: Where e is the irradiance of the solid angle where a single "light" is located; N i is the number of "rays" that fall within the pixel; At this point, a simulated distorted image is obtained after the wavefront of the light emitted by the actual object is modulated by the deformable mirror.

9. The method for simulation detection of deformable mirror performance according to claim 8, characterized in that: The step S4 comprises: Based on the known distorted wavefront, the point spread function is calculated, and the original image is convolved with the point spread function to obtain the ideal distorted image.

10. The method for simulation detection of deformable mirror performance according to claim 9, characterized in that: The step S4 further comprises: When evaluating the static performance of the deformable mirror, the mean square error, peak signal-to-noise ratio and structural similarity evaluation indicators are selected: When evaluating the dynamic performance of the deformable mirror, the dynamic absolute value is introduced. The dynamic absolute value integrates the difference between the SSIM values ​​of the simulated distorted image and the ideal distorted image within the deformation interval of the deformable mirror over time. DAV intuitively reflects the dynamic performance of the deformable mirror: Where BD is the bandwidth of the deformable mirror, SSIM simulation is the continuous SSIM of the simulated distorted image, SSIM random It is a high-frequency dynamic distortion image caused by high-frequency random dynamic medium; The ideal distorted image and the tracked distorted image are compared and analyzed by means of mean square error, peak signal-to-noise ratio, structural similarity and dynamic absolute value to obtain the performance of the deformable mirror for wavefront reproduction under the current number, arrangement and mirror material of the actuators. At the same time, the influence of different incident angles on the imaging performance of the deformable mirror is also evaluated through the changes in the above parameters.

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