Wavefront sensing system using single-channel polarization encoding and wavefront information decoding method

Abstract

The present invention discloses a wavefront sensing system and a wavefront information decoding method using single-channel polarization encoding. The polarization information in the wavefront signal is utilized for the first time to realize polarization encoding and decoding of the spot pattern position information, getting rid of the dependence of the traditional Shack-Hartmann sensor on the photoelectric array sensor, while also solving the pain points in the wavefront detection of dim targets, exploring the application potential of single-point detectors in the field of wavefront sensing, and further expanding the application field of adaptive optical systems.

Description

Technical Field

[0001] The present invention relates to the field of adaptive optics, and in particular to a wavefront sensing system and a wavefront information decoding method using single-channel polarization encoding. Background Art

[0002] In the field of adaptive optics, wavefront sensing systems that can measure wavefront aberrations in real time play an important role. The most widely used of these is the Shack-Hartmann wavefront sensing system. For conventional targets, the Shack-Hartmann sensing system can achieve stable and accurate wavefront detection, but for dim targets, the system cannot achieve effective wavefront detection due to the sensitivity and noise limitations of the photoelectric array sensor itself. In fact, since the echo signal of the observed target is very weak, even the use of high-end array sensors that can be deeply cooled cannot significantly improve the signal-to-noise ratio of the system, and also increases the system cost by millions of yuan. Therefore, it is necessary to develop a wavefront sensing system with high sensitivity, high signal-to-noise ratio and low cost for dim targets to further expand the application scope of adaptive optics systems. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a wavefront sensing system and a wavefront information decoding method using single-channel polarization coding, which solves the problem of coding delay without manual intervention in polarization coding work; and solves the problems of low sensitivity, low signal-to-noise ratio and high cost of the existing Shack-Hartmann wavefront sensing system in detecting dim targets.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a wavefront sensing system using single-channel polarization encoding, comprising:

[0005] A microlens array is used to focus the target echo signal;

[0006] A polarization encoding element, used to encode the position information of the incident light spot obtained after the microlens array is focused into polarization information;

[0007] An image transmission system, used for imaging the focused light spot pattern obtained by the polarization coding element on the light spot sorting system;

[0008] The light spot sorting system is used to trigger the light spots to be reflected or transmitted into the polarization decoding system in sequence through a synchronization signal.

[0009] The present invention encodes the position information of the focused light spot of the Hartmann sensor directly into the polarization information. The polarization encoding work can be naturally completed in the physical process of signal transmission without human intervention. The polarization encoding process occurs simultaneously for all light spots, and since it is a physical process, no encoding delay is generated.

[0010] The sub-lenses of the microlens array are circular, rectangular or hexagonal in structure. Circular sub-lenses are easy to process and have low cost; rectangular and hexagonal sub-lenses have high filling rates and thus high signal-to-noise ratios.

[0011] The polarization encoding element includes a radial polarizer or a radial polarizer array; the radial polarizer or the subunit of the radial polarizer array has the same outer dimensions as the sub-lens of the microlens array, and the projection surfaces of the radial polarizer or the subunit of the radial polarizer array and the sub-lens of the microlens array are perpendicular to the optical axis plane.

[0012] In order to modulate the polarization distribution of the focused light spot and perform effective wavefront sensing, the system needs to be able to describe the light spot position distribution on the focal plane of the microlens. At the same time, in order to ensure that the effective area of ​​the focused light spot on the polarization coding element is minimized and improve the system accuracy, in the present invention, the polarization coding element is arranged at the focal plane of the microlens array.

[0013] In order to meet the requirements for setting up the optical system for imaging transmission, the imaging system is a 4F imaging system, and the distance between the two positive lenses of the 4F imaging system is the sum of the focal lengths of the two positive lenses; the front focal plane of the 4F imaging system coincides with the focal plane of the microlens array.

[0014] The light spot sorting system includes a total internal reflection prism, a spatial light modulator, and a focusing lens; the working surface of the spatial light modulator coincides with the rear focal plane of the image transmission system; the optical axis of the focusing lens and the normal line of the working surface of the spatial light modulator are on the same plane, and the optical axis of the focusing lens and the normal line of the working surface of the spatial light modulator are symmetrical about the normal line of the light splitting surface of the total internal reflection prism. The present invention adopts a spatial light modulator (SLM) for light splitting, and at the same time, the high refresh rate of the SLM is used to compensate for the adverse effect of a single-point detector on the system frame rate.

[0015] The image transmission system images the focused spot pattern passing through the polarization encoding element onto the working surface of the spatial light modulator, divides the effective area of ​​the working surface into N sub-areas of equal area according to the number N of spots on the working surface of the spatial light modulator, and triggers the spatial light modulator through a synchronization signal to sequentially reflect or transmit the spots on the N sub-areas into the polarization decoding system; preferably, the sub-areas are rectangular, circular or triangular. The present invention realizes the flipping of sub-areas one by one through the bistable control of the spatial light modulator, and sends the spots into the polarization decoding system in sequence. When a sub-area flips forward, the remaining sub-areas flip in the opposite direction, thereby avoiding crosstalk between spot signals. The definition of the sub-area of ​​the SLM is very flexible and can be adjusted accordingly according to the sub-unit shape of the microlens array or the radial polarizer array.

[0016] In the present invention, the polarization decoding system is an array detector system or a single point detector system.

[0017] As an inventive concept, the present invention also provides a wavefront information decoding method, the method comprising:

[0018] In the plane where the polarization coding element of the above wavefront sensing system is located, a plane rectangular coordinate system is established with the center O of the polarizer as the center, the polarization direction of the 0° polarizer in the linear polarizer as the X-axis, and the vertical X-axis as the Y-axis, and the calculated spot polarization information (AOP, DOP) is mapped to the coordinate system XOY, that is, the position information (x, y) of the spot on the polarization coding element is obtained; x = dcos (AOP), y = dsin (AOP); (I, Q, U) is the Stokes vector, d is the distance between the center O of the polarization coding element and the center O' of the light spot;

[0019] The light intensity signal is I 0° / I 45° / I 90° hour,

[0020] The light intensity signal is I 0° / I 60° / I 120° hour,

[0021] The light intensity signal is I 0° / I 45° / I 90° / I 135° hour,

[0022] The polarization decoding process of the present invention only involves simple four arithmetic operations and trigonometric function operations. The decoding process is simple and practical, which saves a lot of time spent on the estimation of the spot centroid position of the traditional Hartmann wavefront sensor system and greatly improves the decoding efficiency.

[0023] As an inventive concept, the present invention also provides a wavefront sensing method of the above wavefront sensing system, comprising:

[0024] 1) The spatial light modulator is controlled by triggering a synchronous signal, so that the light spots on the N sub-areas of the spatial light modulator pass through the polarization decoding system in turn, and the position information of each light spot is solved in turn, thereby generating the focus light spot pattern of the entire microlens array, that is, the light spot position information set of the current frame {(x N ,y N )}; wherein each position information (x, y) in the light spot position information set is calculated by the above decoding method;

[0025] 2) Repeat the above step 1) to obtain the light spot position change information set {(Δx N ,Δy N )}.

[0026] The present invention utilizes the polarization information in the wavefront signal for the first time, realizes the polarization encoding and decoding of the spot pattern position information, gets rid of the dependence of the traditional Shack-Hartmann sensor on the photoelectric array sensor, and solves the problems of low sensitivity, low signal-to-noise ratio and high cost of the existing Shack-Hartmann wavefront sensor system in detecting dim targets.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention utilizes the polarization information in the wavefront signal for the first time, realizes the polarization encoding and decoding of the spot pattern position information, gets rid of the dependence of the traditional Shack-Hartmann sensor on the photoelectric array sensor, and also solves the pain points in the wavefront detection of dim targets, explores the application potential of single-point detectors in the field of wavefront sensing, and further expands the application field of adaptive optical systems;

[0029] 2. The use of a highly sensitive single-point detector as the core device for polarization decoding greatly improves the sensitivity and signal-to-noise ratio of the system from the perspective of sensing mechanism, and significantly reduces the system cost;

[0030] 3. The polarization encoding work of the present invention can be completed naturally in the physical process of signal transmission, without manual intervention or extra time, thus saving encoding time;

[0031] 4. The polarization decoding process of the present invention only involves simple arithmetic operations and trigonometric functions, which can be completed at high speed in the FPGA acceleration circuit of the data processing system, saving a lot of time spent on the estimation of the spot centroid position in the traditional Hartmann wavefront sensor system;

[0032] 5. The efficient encoding and decoding design of the present invention can not only fully meet the requirements of wavefront sensing for the system frame rate, but also reserve computing power for further increasing the number of sub-apertures of the microlens array and improving the wavefront sensing accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structural principle of a wavefront sensing system based on single-channel polarization coding provided by an embodiment of the present invention;

[0034] FIG2(a), FIG2(b) and FIG2(c) are schematic diagrams of the structural principle of the wavefront sensing system corresponding to the single-point detector system under the linear polarizer combinations of 0° / 45° / 90°, 0° / 60° / 120°, and 0° / 45° / 90° / 135°, respectively;

[0035] Figure 3 This is a simulation diagram and a partial magnified diagram of the effect of a light spot after being encoded by a polarization coding element in an embodiment of the present invention;

[0036] Figure 4 This is a comparison diagram of polarization modulation of light spots at different positions on a polarization coding element according to an embodiment of the present invention;

[0037] Figure 5 This is a diagram showing the polarization decoding effect after parallel light passes through a radial polarizer array in an experiment of an embodiment of the present invention;

[0038] Figure 6 This is a diagram showing the polarization decoding effect of a focused light spot of a microlens array after passing through a radial polarizer array in an experiment of an embodiment of the present invention;

[0039] Figure 7 This is the polarization decoding effect diagram after the wavefront disturbance is introduced into the system;

[0040] Figure 8 This is the differential effect diagram of polarization decoding before and after the wavefront disturbance is introduced into the system. DETAILED DESCRIPTION

[0041] like Figure 1 As shown, an embodiment of the present invention includes a microlens array, a polarization encoding element, a 4F image transmission system, a light spot sorting system, a polarization decoding system, and a data processing system.

[0042] The wavefront information of the distant target is focused by the microlens array and converted into a spot pattern distribution on the focal plane of the microlens array. After passing through the radial polarization array, the spot pattern distribution is encoded from the spatial dimension to the polarization dimension, and the polarization state information carried by different spots is different. The spot pattern is then enlarged or reduced to a suitable size through the 4F imaging system and imaged onto the surface of the digital micromirror device. The digital micromirror device reflects the spot into the imaging lens in sequence through the focal plane, and performs polarization decoding imaging in the black and white polarization camera. The final result is recorded and processed by the microprocessor.

[0043] The sub-units (sub-lenses) of the microlens array include but are not limited to circular, rectangular, hexagonal and other structures.

[0044] In the embodiment of the present invention, the polarization coding element includes but is not limited to a radial polarizer and a radial polarizer array. The radial polarizer array and the subunits of the radial polarizer array should have the same external dimensions and spatial projection positions on the plane perpendicular to the optical axis as the subunits of the microlens array. The polarization coding element is located at the focal plane of the microlens array and performs polarization coding on the incident microlens array focused light spot. The focused light spots corresponding to different microlens array subunits will carry different polarization information after being emitted by the polarization coding element, and the polarization information and its projection position on the polarization coding element satisfy a unique corresponding relationship.

[0045] The 4F imaging system includes two positive lenses with known focal lengths. The distance between the two lenses is the sum of their focal lengths. Its function is to scale the light spot pattern formed by the microlens to a suitable size. The 4F imaging system is located after the polarization coding element, and the front focal plane of the 4F imaging system coincides with the focal plane of the microlens array.

[0046] The spot sorting system includes a total internal reflection (TIR) ​​prism, a spatial light modulator, and a focusing lens. The total internal reflection prism is used with a reflective spatial light modulator, and its total reflection angle can be calculated based on the optical path structure (Pan Cheng. High-speed scanning imaging system based on digital micro-mirror array [D]. Nanjing University of Science and Technology, 2012.). Spatial light modulators include but are not limited to liquid crystal spatial light modulators, microchannel plate spatial light modulators, digital micromirror devices (DMD, Digital Micromirror Device), etc. The spot sorting system is located after the 4F imaging system, and ensures that the working surface of the spatial light modulator coincides with the back focal plane of the 4F imaging system. At the same time, the optical axis of the focusing lens and the normal of the working surface of the spatial light modulator are in the same plane, and the two are symmetrical about the normal of the light splitting surface of the total internal reflection prism in the spot sorting system.

[0047] Further, the polarization decoding system can be an array detector system or a single point detector system. The array detector system includes but is not limited to one of a black and white polarization camera and a color polarization camera. The single point detector system includes a spectroscopic element, a linear polarizer, and a single point detector. The spectroscopic element includes a four-glued spectroscope for three-way spectroscopic, a spectroscope combination for two-way spectroscopic, a spectroscope combination for two-way spectroscopic, and the like, and the polarization characteristics and frequency characteristics of the outgoing light remain unchanged after passing through the spectroscopic element. The linear polarizer includes a combination of 0° / 45° / 90° (as shown in FIG. 2(a)), 0° / 60° / 120° (as shown in FIG. 2(b)), 0° / 45° / 90° / 135° (as shown in FIG. 2(c)), and the like. The single point detector can use an avalanche photodiode (APD), a photomultiplier tube (PMT), a single photon counter (SPC), and the like. The single-point detector system can adopt a three-way splitting solution or a four-way splitting solution according to different polarization solution combinations, and each splitting path contains a linear polarizer and a single-point detector, so that the light intensity information at the polarization angle can be obtained synchronously.

[0048] The experimental scene of the present invention includes a large-aperture parallel light source, a microlens array, a radial polarizer array, a 4F image transmission system, a total internal reflection prism, a digital micromirror device, a focusing lens, and a black-and-white polarization camera. It should be noted that the target echo signal at infinity can be approximately considered as parallel light, so a large-aperture parallel light source is used as the incident light of the system in the experiment to simulate this process.

[0049] In one embodiment of the present invention, the data processing system includes but is not limited to a data acquisition card, a microprocessor, an industrial computer, etc. The microprocessor can control the data acquisition card to drive the spatial light modulator according to the synchronization signal and simultaneously collect the light intensity signal obtained by each single point detector.

[0050] Another embodiment of the present invention provides a wavefront information encoding method using a radial polarization element, which uses the radial polarization element to encode the position information of the focused light spot onto the polarization information, and includes the following steps:

[0051] First, the target echo signal at infinity is focused by a microlens array;

[0052] Then, the position information of the incident light spot is encoded into the polarization information using the polarization encoding element located in the focal plane of the microlens array. The polarization encoding process occurs simultaneously for all light spots, and since it is a physical process, no encoding delay is generated.

[0053] Finally, the polarization-encoded focused spot pattern is imaged on the working surface of the spatial light modulator through the 4F imaging system. According to the number N of spots on the working surface of the spatial light modulator, the effective area of ​​the working surface is divided into N sub-areas of equal area, where the sub-areas can be rectangular, circular, triangular, etc. The spatial light modulator is controlled by triggering the synchronization signal to reflect or transmit the spots on the N sub-areas into the polarization decoding system in turn.

[0054] Another embodiment of the present invention provides a wavefront information decoding method using a multi-path splitting structure, which calculates the position information of the light spot on the polarization coding element through multi-path polarization information, including the following steps:

[0055] The light spots transmitted one by one through the light spot sorting system are divided into three or four paths by the light splitting element (the polarization camera is a multi-path coaxial system), and the light intensity of each light spot is equal;

[0056] Then the light spot passes through linear polarizers of different angles in the split light path and enters the detector to generate light intensity signals. Depending on the split light structure and polarizer combination used, the light intensity signals obtained are I 0° / I 45° / I 90° ,I 0° / I 60° / I 120° ,I 0° / I 45° / I 90° / I 135° The above process is carried out simultaneously in each split light path;

[0057] Next, the data acquisition card collects the multi-path light intensity signals of the same outgoing light spot according to the synchronization signal, and transmits the light intensity signals to the microprocessor to solve the polarization state of the light spot. The polarization angle (AOP, Angle of Polarization) and degree of polarization (DOP, Degree of Polarization) information corresponding to the light spot can be obtained through polarization state solution. The polarization state solution follows the following formula:

[0058]

[0059]

[0060]

[0061]

[0062]

[0063] Formulas 3 to 5 respectively give the calculation process of the Stokes vector under different spectroscopic structures and polarizer combinations. 0° / I 45° / I 90° ,I 0° / I 60° / I 120° ,I 0° / I 45° / I 90° / I 135° Substituting the combined light intensity data into the corresponding formula can obtain the components of the Stokes vector (I, Q, U), and then substituting it into formula 1 and formula 2 to obtain the polarization angle and polarization degree information corresponding to the current light spot.

[0064] Finally, in the plane where the polarization coding element is located, a plane rectangular coordinate system is established with the center O of the polarizer as the center, the polarization direction of the 0° polarizer in the linear polarizer as the X-axis, and the vertical X-axis as the Y-axis. The calculated spot polarization information (AOP, DOP) is mapped to the coordinate system XOY, and the position information (x, y) of the spot on the polarization coding element can be obtained, and the mapping relationship between the two satisfies the following formula:

[0065]

[0066] l m =L m cosθ m (Formula 7)

[0067]

[0068]

[0069] x=dcos(AOP),y=dsin(AOP) (Formula 10)

[0070] The spot radius R is a known quantity, which can be calculated based on the size parameters of the microlens array subaperture and the conjugate relationship in the aforementioned optical path; the angle θ between adjacent polarization states of the polarization coding element is a known quantity, which can be obtained based on the processing parameters of the polarization coding element; d is the distance between the center O of the polarization coding element and the centroid O' of the spot, the number of polarization states in the spot is n, θ m is the angle between the mth polarization state and the symmetry axis of all polarization states in the spot, L m is the actual length of the mth polarization state in the spot, l m is the projection length of the mth polarization state in the spot on the symmetry axis of all polarization states.

[0071] Formulas 6 to 10 can be combined to calculate the precise position coordinates (x, y) of the center of mass of the current light spot in the XOY coordinate system. The data processing system uses a synchronous signal to trigger the spatial light modulator to make the light spots on the N sub-areas pass through the polarization encoding system and the polarization decoding system in turn, and complete the position information of each light spot in turn, thereby generating the focus light spot pattern of the entire microlens array, that is, the light spot position information set of the current frame {(x N ,y N )}, by repeating the encoding and decoding process of the above light spot pattern, the light spot position change information set {(Δx N ,Δy N )}, thereby achieving accurate and robust wavefront sensing.

[0072] Figure 3 This is a simulation diagram and a partial magnified diagram of the effect of the light spot after being encoded by the polarization encoding element. Figure 3 It can be seen that after polarization encoding under an ideal state (the spot shape is a perfect circle and the light intensity satisfies the Gaussian distribution), different positions in the spot have different polarization directions, and all polarization directions are symmetrical about the line connecting the center O of the polarization encoding element and the center of the spot O', which is determined by the shape of the spot and the structural characteristics of the polarization encoding element. At the same time, by using the symmetry of the internal polarization distribution of the spot after polarization modulation, the AOP can be directly calculated in the subsequent polarization decoding process, that is, the precise angle between the straight line OO' where the center of the spot is located and the X-axis.

[0073] Figure 4 This is a comparison of polarization modulation of light spots at different positions on the polarization coding element. Figure 4 It can be seen that when the angle between OO' and the X-axis remains unchanged, and the distance d between the center of the polarization coding element O and the centroid of the light spot O' changes, the polarization directions at different positions in the light spot remain symmetrical, but the ratio of the horizontal and vertical components after orthogonal decomposition of each polarization direction changes significantly, that is, the degree of polarization of the light spot changes. In the extreme case, when d = 0, the degree of polarization of the light spot is 0, and when d = ∞, the degree of polarization of the light spot is 1. Therefore, d can be determined by solving the DOP in the subsequent polarization decoding process, and then the position (x, y) of the centroid of the light spot in the XOY coordinate system can be calculated by formula 10.

[0074] Figure 5 The polarization decoding effect of parallel light after passing through the radial polarizer array in the experiment is given. Since this embodiment uses a black and white polarization camera, according to its structural principle, the global solution of polarization distribution can be performed using formulas 1, 2, and 5. Figure 5 It can be seen that different subunits of the radial polarizer array have independent polarization encoding capabilities.

[0075] Figure 6 The polarization decoding effect of the focused light spot of the microlens array after passing through the radial polarizer array in the experiment is given. Since the present embodiment adopts parallel light incidence, the polarization distribution of the light spot in different sub-units tends to be consistent. Figure 6 It can be seen that the position information of the light spots in different sub-units can be accurately extracted through polarization decoding.

[0076] Figure 7 The polarization decoding effect after the system introduces wavefront disturbance is given. To ensure the experimental accuracy, this embodiment uses a 1mm thick parallel glass plate as a wave plate disturbance to verify the effectiveness of the system. Figure 6 and Figure 7 It can be seen that the polarization decoding effect collected by the polarization camera has changed significantly before and after the wave plate disturbance is introduced into the system. The slight movement of the spot position reflects the continuous change of the wavefront. Figure 8 The differential effect of polarization decoding before and after the wavefront disturbance is introduced into the system is given.

[0077] In the subsequent experimental data processing, the polarization state distribution diagram collected by the polarization camera is used to calculate the polarization degree and polarization angle of a certain light spot corresponding to different sub-units. The position (x, y) of the light spot in the XOY coordinate system can be obtained by using formulas 6 to 10. Similarly, the complete set of light spot centroid positions {(x N ,y N )}. In practical applications of wavefront sensing, it is necessary to compare {(x N ,y N )} to obtain the spot centroid position change set {(Δx N ,Δy N )}, and then use Zernike polynomials according to {(Δx N ,Δy N )} By fitting the Zernike coefficients of each order of the wavefront phase, the wavefront sensing and reconstruction can be realized.

[0078] It can be seen from the above experiments that the present invention can achieve high-precision wavefront sensing in a weak light environment by means of polarization encoding.

Claims

1. A wavefront sensing system using single-channel polarization encoding, characterized in that: include: A microlens array is used to focus the target echo signal; A polarization encoding element, used to encode the position information of the incident light spot obtained after the microlens array is focused into polarization information; An image transmission system, used for imaging the focused light spot pattern obtained by the polarization coding element on the light spot sorting system; the polarization coding element is arranged at the focal plane of the microlens array; A light spot sorting system is used to trigger the light spots to be reflected or transmitted into the polarization decoding system in sequence through a synchronization signal; The light spot sorting system includes a total internal reflection prism, a spatial light modulator, and a focusing lens; the working surface of the spatial light modulator coincides with the rear focal plane of the image transmission system; the optical axis of the focusing lens and the normal of the working surface of the spatial light modulator are on the same plane, and the optical axis of the focusing lens and the normal of the working surface of the spatial light modulator are symmetrical about the normal of the splitting surface of the total internal reflection prism.

2. The wavefront sensing system using single-channel polarization encoding according to claim 1, characterized in that: The sub-lenses of the microlens array are circular, rectangular or hexagonal in structure.

3. The wavefront sensing system using single-channel polarization encoding according to claim 1, characterized in that: The polarization encoding element includes a radial polarizer or a radial polarizer array; the radial polarizer or the subunit of the radial polarizer array has the same outer dimensions as the sub-lens of the microlens array, and the projection surfaces of the radial polarizer or the subunit of the radial polarizer array and the sub-lens of the microlens array are perpendicular to the optical axis plane.

4. The wavefront sensing system using single-channel polarization encoding according to claim 1, characterized in that: The image transmission system is a 4F image transmission system, the distance between the two positive lenses of the 4F image transmission system is the sum of the focal lengths of the two positive lenses; the front focal plane of the 4F image transmission system coincides with the focal plane of the microlens array.

5. The wavefront sensing system using single-channel polarization encoding according to claim 1, characterized in that: The image transmission system images the focused light spot pattern passing through the polarization encoding element onto the working surface of the spatial light modulator, divides the effective area of ​​the working surface into N sub-areas of equal area according to the number N of light spots on the working surface of the spatial light modulator, and triggers the spatial light modulator through a synchronization signal to sequentially reflect or transmit the light spots on the N sub-areas into the polarization decoding system.

6. The wavefront sensing system using single-channel polarization encoding according to claim 5, characterized in that: The sub-area is rectangular, circular or triangular.

7. The wavefront sensing system using single-channel polarization encoding according to claim 1, characterized in that: The polarization decoding system is an array detector system or a single point detector system.

8. A wavefront information decoding method, characterized in that: The method includes: In the plane where the polarization coding element of the wavefront sensing system described in any one of claims 1 to 7 is located, a plane rectangular coordinate system is established with the center O of the polarization coding element as the center, the polarization direction of the 0° polarizer in the polarization coding element as the X-axis, and the vertical X-axis as the Y-axis, and the calculated spot polarization information (AOP, DOP) is mapped to the coordinate system XOY, that is, the position information (x, y) of the spot on the polarization coding element is obtained; x=dcos(AOP),y=dsin(AOP); (I, Q, U) is the Stokes vector, d is the center of the polarization coding element O and the center of the light spot O ’ Spacing; The light intensity signal is I 0° / I 45° / I 90° hour, The light intensity signal is I 0° / I 60° / I 120° hour, Optical signal station I 0° / I 45° / I 90° / I 135° Time, 9. A wavefront sensing method of the wavefront sensing system according to any one of claims 1 to 7, characterized in that: include: 1) The spatial light modulator is controlled by triggering a synchronous signal, so that the light spots on the N sub-areas of the spatial light modulator pass through the polarization decoding system in turn, and the position information of each light spot is solved in turn, thereby generating the focus light spot pattern of the entire microlens array, that is, the light spot position information set of the current frame {(x N ,y N )}; wherein each position information (x, y) in the light spot position information set is calculated by the method of claim 8; 2) Repeat the above step 1) to obtain the light spot position change information set {(Δx N ,Δy N )}.

Images