Wavefront sensor, wavefront measurement method, system and electronic device

Abstract

The present invention provides a wavefront sensor, a wavefront measurement method, a system and an electronic device, relating to the technical field of optical measurement. The wavefront sensor includes: a semi-reflective semi-transmissive mirror, a first microlens array, a second microlens array, a first detector and a second detector; the semi-reflective semi-transmissive mirror is used to separate the incident wavefront to be measured into a reflected wavefront and a transmitted wavefront; the first microlens array is perpendicular to the reflection optical path of the semi-reflective semi-transmissive mirror and is disposed on the focal plane of the reflection optical path of the semi-reflective semi-transmissive mirror; the second microlens array is perpendicular to the transmission optical path of the semi-reflective semi-transmissive mirror and is disposed on the focal plane of the transmission optical path of the semi-reflective semi-transmissive mirror. The wavefront sensor, the wavefront measurement method, the system and the electronic device provided by the present invention can significantly improve the measurement ability of the wavefront sensor for high-curvature and large-amplitude wavefront distortion without reducing the sensitivity of the wavefront sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of optical measurement, and particularly to a wavefront sensor, a wavefront measurement method, a system and an electronic device. Background Art

[0002] A wavefront sensor, also known as a wavefront detector or a wavefront analyzer, is a device for precisely measuring and analyzing an optical wavefront.

[0003] In related technologies, a traditional wavefront sensor can divide an incident wavefront into multiple sub-wavefronts through a microlens array, form light spots on a detector, and reconstruct the wavefront topography by obtaining the offsets of the light spots to obtain complete wavefront information.

[0004] However, traditional wavefront sensors in related technologies have defects such as complex hardware operations or slow subsequent calculation speeds when measuring wavefronts with high curvature or large dynamic range. These defects limit the application and performance of traditional wavefront sensors in wavefront measurement with high curvature or large dynamic range. Therefore, how to improve the subsequent calculation speed without increasing the hardware operation complexity of the wavefront sensor, so as to improve the application and performance of the wavefront sensor when measuring wavefronts with high curvature or large dynamic range. Summary of the Invention

[0005] The present invention provides a wavefront sensor, a wavefront measurement method, a system and an electronic device, which are used to solve the defects of complex hardware structure and slow subsequent calculation speed of traditional wavefront sensors in related technologies when measuring wavefronts with high curvature or large dynamic range, and realize improving the subsequent calculation speed without increasing the hardware operation complexity of the wavefront sensor, thereby improving the application and performance of the wavefront sensor when measuring wavefronts with high curvature or large dynamic range.

[0006] The present invention provides a wavefront sensor, including: a semi-reflective and semi-transmissive mirror, a first microlens array, a second microlens array, a first detector and a second detector; the first microlens array and the second microlens array are the same microlens array; the first detector and the second detector are the same detector;

[0007] The semi-reflective and semi-transmissive mirror is composed of a plurality of reflection parts and a plurality of transmission parts. The reflection parts and the transmission parts are both rectangular and have equal areas. Each of the reflection parts and each of the transmission parts are arranged alternately. The semi-reflective and semi-transmissive mirror is used to separate an incident wavefront to be measured into a reflected wavefront and a transmitted wavefront;

[0008] The first microlens array is perpendicular to the reflection optical path of the semi-reflective and semi-transmissive mirror and is disposed on the focal plane of the reflection optical path of the semi-reflective and semi-transmissive mirror;

[0009] The second microlens array is perpendicular to the transmission optical path of the semi-reflective and semi-transmissive mirror and is disposed on the focal plane of the transmission optical path of the semi-reflective and semi-transmissive mirror;

[0010] The first detector is coaxially disposed with the first microlens array, and the first detector is configured to record a first spot distribution map formed after the reflected wavefront passes through the first microlens array;

[0011] The second detector is coaxially disposed with the second microlens array, and the second detector is configured to record a second spot distribution map formed after the transmitted wavefront passes through the second microlens array.

[0012] A wavefront sensor according to the present invention further includes: a front optical lens; the front optical lens includes at least one of a beam reducing lens, a beam expanding lens, and a collimating lens disposed along the incident optical path of the wavefront to be measured; the front optical lens is coaxially disposed with the semi-reflective and semi-transmissive mirror, and the front optical lens and the semi-reflective and semi-transmissive mirror are sequentially disposed along the incident optical path of the wavefront to be measured.

[0013] A wavefront sensor according to the present invention, the front optical lens further includes: a filter disposed along the incident optical path of the wavefront to be measured.

[0014] A wavefront sensor according to the present invention, both the first detector and the second detector are high-speed charge-coupled device (CCD) detectors or complementary metal oxide semiconductor (CMOS) detectors.

[0015] The present invention further provides a wavefront measurement method, including: obtaining a first spot distribution map and a second spot distribution map, the first spot distribution map and the second spot distribution map being generated based on any one of the wavefront sensors described above; reconstructing the wavefront to be measured based on the first spot distribution map and the second spot distribution map to obtain the phase information of the wavefront to be measured.

[0016] A wavefront measurement method according to the present invention, the reconstructing the wavefront to be measured based on the first spot distribution map and the second spot distribution map to obtain the phase information of the wavefront to be measured includes:

[0017] Recording the spot positions in the first spot distribution map at a first type of positions in a blank matrix, and recording the spot positions in the second spot distribution map at a second type of positions in the blank matrix to obtain a target matrix, wherein the first type of positions and the second type of positions in the blank matrix are determined based on the arrangement of each reflection part and each transmission part in the semi-reflective and semi-transmissive mirror in the wavefront sensor, the first type of positions corresponds to the reflection part, and the second type of positions corresponds to the transmission part;

[0018] Based on the target matrix, reconstruct the wavefront to be measured to obtain the phase information of the wavefront to be measured.

[0019] According to a wavefront measurement method provided by the present invention, recording the positions of the light spots in the first light spot distribution map at a first type of positions in the blank matrix, and recording the positions of the light spots in the second light spot distribution map at a second type of positions in the blank matrix to obtain a target matrix includes:

[0020] Perform grid division on the first light spot distribution map and the second light spot distribution map respectively. Generate a target number of grids of the same size in the first light spot distribution map, and generate the target number of grids of the same size in the second light spot distribution map, where the target number is the total number of the first type of positions and the second type of positions in the blank matrix;

[0021] Based on the distribution of the first type of positions in the blank matrix, determine the grid corresponding to each first type of position in the first light spot distribution map, and based on the distribution of the second type of positions in the blank matrix, determine the grid corresponding to each second type of position in the second light spot distribution map;

[0022] For the grid corresponding to each first type of position, use each side of the grid corresponding to each first type of position as the hypotenuse, and generate right triangles in the direction away from the grid corresponding to each first type of position to obtain the right triangles corresponding to each first type of position. For the grid corresponding to each second type of position, use each side of the grid corresponding to each second type of position as the hypotenuse, and generate right triangles in the direction away from the grid corresponding to each second type of position to obtain the right triangles corresponding to each second type of position;

[0023] Write the position information of the light spots in the area of the grid and the right triangles corresponding to each first type of position in the first light spot distribution map to the positions of each first type of position in the blank matrix, and write the position information of the light spots in the area of the grid and the right triangles corresponding to each second type of position in the second light spot distribution map to the positions of each second type of position in the blank matrix.

[0024] According to a wavefront measurement method provided by the present invention, before obtaining the first light spot distribution map and the second light spot distribution map, the method further includes:

[0025] Calibrate the wavefront sensor based on a standard parallel light source to establish the coaxial relationship between the components in the wavefront sensor.

[0026] The present invention also provides a wavefront measurement system, comprising: the wavefront sensor as described in any one of the above and an electronic device; the electronic device is electrically connected to the first detector and the second detector in the wavefront sensor respectively;

[0027] The electronic device is configured to reconstruct the wavefront to be measured based on the first spot distribution map and the second spot distribution map, and obtain the phase information of the wavefront to be measured.

[0028] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the wavefront measurement method as described in any one of the above is implemented.

[0029] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the wavefront measurement method as described in any one of the above is implemented.

[0030] The present invention also provides a computer program product, comprising a computer program. When the computer program is executed by a processor, the wavefront measurement method as described in any one of the above is implemented.

[0031] The wavefront sensor, wavefront measurement method, system and electronic device provided by the present invention. The wavefront sensor includes a semi-reflective and semi-transmissive mirror, a first microlens array, a second microlens array, a first detector and a second detector. The incident wavefront to be measured is separated into a reflected wavefront and a transmitted wavefront by the semi-reflective and semi-transmissive mirror. Then, two spot distribution maps can be obtained respectively through two sets of completely identical microlens arrays and detectors. On the basis of not reducing the sensitivity of the wavefront sensor, the measurement ability of the wavefront sensor for high-curvature and large-amplitude wavefront distortion is significantly improved. By introducing a semi-reflective and semi-transmissive mirror and another set of microlens arrays and detectors, more spot position information can be obtained, the corresponding relationship between the spots and the microlens array can be obtained more accurately, the accuracy of wavefront measurement can be improved, while the dynamic range of the wavefront sensor is increased, excessive hardware complexity is avoided, the feasibility and cost-effectiveness of the wavefront sensor can be ensured, the real-time wavefront measurement requirements can be met, the application range of the wavefront sensor is expanded, and the higher optical measurement requirements can be satisfied. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1It is a schematic diagram of the principle of a Shack - Hartmann wavefront sensor in the related art.

[0034] Figure 2 It is a schematic structural diagram of the wavefront sensor provided by the present invention.

[0035] Figure 3 It is a schematic structural diagram of the semi - reflective and semi - transmissive mirror in the wavefront sensor provided by the present invention.

[0036] Figure 4 It is a schematic diagram of the grid corresponding to a type of position in the first spot distribution diagram in the wavefront measurement method provided by the present invention.

[0037] Figure 5 It is a schematic flow diagram of the wavefront measurement method provided by the present invention.

[0038] Figure 6 It is a schematic structural diagram of the electronic device provided by the present invention. Detailed Embodiments

[0039] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0040] In the description of the invention, it should be noted that, unless otherwise clearly defined and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] In the description of this application, the terms "first", "second", etc. are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually of the same category, and do not limit the number of objects. For example, the first object can be one or more. In addition, in the description of this application, " / " indicates at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0042] It should be noted that the Shack-Hartmann Wavefront Sensor (SHWFS) is a commonly used wavefront sensor in related technologies. Figure 1 It is a schematic diagram of the principle of the Shack-Hartmann wavefront sensor in related technologies. As Figure 1 shown, the Shack-Hartmann wavefront sensor includes a microlens array and a detector. The microlens array is an array composed of many small lenses (sub-apertures) arranged regularly. When the wavefront to be measured is incident on the microlens array, the microlens array can divide the wavefront to be measured into multiple sub-wavefronts. The detector is located in the focal plane of the microlens array and can be used to record the spots formed by the focusing of each sub-aperture.

[0043] When there is distortion in the wavefront to be measured (such as caused by optical aberration or medium perturbation), the position of the spot in the detector image will deviate from its ideal position (reference benchmark). By obtaining the offset of any spot in the detector image, the local slope of the sub-aperture corresponding to the above spot can be calculated. By integrating the local slopes of all sub-apertures, the phase distribution of the wavefront to be measured can be reconstructed.

[0044] In related technologies, the offset of the spot can be obtained by the centroid estimation method. Specifically, the centroid estimation method can determine the position of the centroid of each spot image in the detector image according to the range corresponding to each sub-aperture of the detector, and then, based on the position of the centroid of each spot image, obtain the offset of the spot.

[0045] In order to improve the adaptability of the Shack-Hartmann wavefront sensor to the measurement of wavefronts with high curvature or large dynamic range, there are the following solutions in related technologies: First, use a spatial light modulator array to open and close the sub-apertures. Only one sub-aperture is opened each time, and then this sub-aperture is closed, and the next sub-aperture is opened. The offset of the spot is detected and recorded, and this operation is repeated until all sub-apertures have been opened once.

[0046] Second, use the iterative extrapolation method based on the B-Spline function to obtain the offset of the spot. This algorithm assumes that the nine points at the center of the detector image correspond to the sub-lenses above them. According to the connection pairs of these spots and sub-lenses, the offset of the spot is fitted by the B-Spline function, and then this function is extrapolated to the nearest unconnected sub-lens to give the expected position of the spot. If a new spot is close enough to these expected positions, it will be selected and connected, and this is repeated until all spots are sorted and numbered.

[0047] Third, the offset of the light spot is obtained by the iterative extrapolation method based on Zernike polynomials. The initialization of this algorithm starts from nine points at the center of the detector image. Zernike polynomials are used to fit the assigned points, and the obtained polynomials are used to extrapolate and predict the positions of the surrounding light spots. The light spot closest to the predicted position is assigned to the corresponding lens, and this process is continuously repeated until all light spots are assigned.

[0048] However, in the first above-mentioned solution, the dynamic switch control of the sub-aperture depends on hardware operations, with a slow processing speed and the need for multiple exposures, making it difficult to meet the requirements of real-time wavefront measurement. Moreover, introducing a spatial light modulator will increase the complexity and cost of the wavefront sensor, and precise control and calibration are required.

[0049] In the second above-mentioned solution, there are high requirements for the distribution of light spots. If the light spots seriously deviate from the sub-aperture or there is data missing, the fitting accuracy will drop significantly, and the iterative process requires multiple calculations, increasing the computational complexity and time overhead.

[0050] In the third above-mentioned solution, the algorithm depends on the initial light spot distribution. If the initial fitting error is large, it may lead to the deviation of the iterative result, and the iterative process requires multiple calculations, increasing the computational complexity and time overhead.

[0051] Therefore, the Shack-Hartmann wavefront sensor in the related technology has defects such as complex hardware operations or slow subsequent calculation speed when measuring wavefronts with high curvature or large dynamic range. These defects limit the application and performance of the Shack-Hartmann wavefront sensor in wavefront measurement with high curvature or large dynamic range, and it is difficult to meet the requirements of real-time wavefront measurement.

[0052] In response to this, the present invention provides a wavefront sensor. The wavefront sensor provided by the present invention can significantly improve the dynamic range and measurement speed of the wavefront sensor by introducing a semi-reflective semi-transmissive mirror, two groups of microlens arrays, and detectors.

[0053] The following combines Figures 2 - 4 to describe the wavefront sensor provided by the present invention.

[0054] Figure 2 is a schematic structural diagram of the wavefront sensor provided by the present invention. The following combines Figure 2 to describe the wavefront sensor provided by the present invention. As Figure 2 shown, the wavefront sensor 201 includes: a semi-reflective semi-transmissive mirror 202, a first microlens array 203, a second microlens array 204, a first detector 205, and a second detector 206; the first microlens array 203 and the second microlens array 204 are the same microlens arrays; the first detector 205 and the second detector 206 are the same detectors.

[0055] The semi-reflective and semi-transmissive mirror 202 is composed of a plurality of reflective parts and a plurality of transmissive parts. Both the reflective parts and the transmissive parts are rectangular and have equal areas. The reflective parts and the transmissive parts are arranged alternately. The semi-reflective and semi-transmissive mirror 202 is used to separate the incident wavefront to be measured into a reflected wavefront and a transmitted wavefront.

[0056] The first microlens array 203 is perpendicular to the reflection optical path of the semi-reflective and semi-transmissive mirror 202 and is disposed on the focal plane of the reflection optical path of the semi-reflective and semi-transmissive mirror 202.

[0057] The second microlens array 204 is perpendicular to the transmission optical path of the semi-reflective and semi-transmissive mirror 202 and is disposed on the focal plane of the transmission optical path of the semi-reflective and semi-transmissive mirror 202.

[0058] The first detector 205 is coaxially arranged with the first microlens array 203. The first detector 205 is used to record the first spot distribution map formed after the reflected wavefront passes through the first microlens array 203.

[0059] The second detector 206 is coaxially arranged with the second microlens array 204. The second detector 206 is used to record the second spot distribution map formed after the transmitted wavefront passes through the second microlens array 204.

[0060] It should be noted that Figure 3 is a schematic structural diagram of the semi-reflective and semi-transmissive mirror in the wavefront sensor provided by the present invention. Figure 3 The black color blocks in Figure 3 represent the reflective parts in the semi-reflective and semi-transmissive mirror 202, Figure 3 and the white color blocks in

[0061] represent the transmissive parts in the semi-reflective and semi-transmissive mirror 202. As Figure 2 shown, different from the traditional semi-reflective and semi-transmissive mirror 202, the multiple reflective parts and multiple transmissive parts in the semi-reflective and semi-transmissive mirror in the embodiment of the present invention are arranged in a checkerboard pattern.

[0062] It can be understood that the transmission optical path of the semi-reflective and semi-transmissive mirror 202 is the same as the incident optical path of the wavefront to be measured, and the reflection optical path of the semi-reflective and semi-transmissive mirror 202 is related to the reflection direction of the reflective part.

[0063] Optionally, the reflection optical path of the semi-reflective and semi-transmissive mirror is perpendicular to the incident optical path of the wavefront to be measured.

[0064] It should be noted that the first microlens array 203 and the second microlens array 204 in the embodiments of the present invention are two completely identical microlens arrays. The first detector 205 and the second detector 206 are two completely identical detectors.

[0065] Optionally, the first microlens array 203 and the second microlens array 204 in the embodiments of the present invention may be the same as the microlens array in the Shack-Hartmann wavefront sensor 201 in the related art. The first detector 205 and the second detector 206 in the embodiments of the present invention may be the same as the detectors in the Shack-Hartmann wavefront sensor 201 in the related art.

[0066] It should be noted that the focal lengths of the first microlens array 203 and the second microlens array 204 are related to the sensitivity and the supported dynamic range of the wavefront sensor 201 provided by the present invention. The larger the focal lengths of the first microlens array 203 and the second microlens array 204 are, the smaller the dynamic range supported by the wavefront sensor 201 is; the smaller the focal lengths of the first microlens array 203 and the second microlens array 204 are, the larger the dynamic range supported by the wavefront sensor 201 is.

[0067] In the embodiments of the present invention, microlens arrays with different focal lengths may be selected as the first microlens array 203 and the second microlens array 204 based on the actual situation of the wavefront to be measured. Under the condition that the dynamic range can be satisfied, microlens arrays with larger focal lengths are selected as the first microlens array 203 and the second microlens array 204 to improve the sensitivity of the wavefront sensor 201.

[0068] As an optional embodiment, both the first detector 205 and the second detector 206 are high-speed charge-coupled device (CCD) detectors or complementary metal oxide semiconductor (CMOS) detectors.

[0069] It should be noted that a high-speed CCD (Charge-Coupled Device) detector is a semiconductor device that converts optical signals into electrical signals. It is integrated with a highly sensitive semiconductor material and can generate corresponding charge signals according to the light irradiating on its surface. When light irradiates on the photosensitive element of the CCD, a current proportional to the light intensity will be generated. These analog signals will be transmitted to the storage unit of the next photosensitive element and merged with the signals of this element until a unified output is formed. Then, these signals will be processed by an amplifier to ensure that the signal intensity of each pixel is consistent, and then converted into a binary digital image matrix by an analog-to-digital conversion chip.

[0070] A CMOS (Complementary Metal Oxide Semiconductor) detector is a type of integrated circuit. In a CMOS image sensor, an amplifier and analog-to-digital conversion logic are integrated on each pixel. When light irradiates the photosensitive diode of the CMOS, the generated analog signal is first amplified by the amplifier and then directly converted into a digital signal. Each photosensitive element can produce a final digital output, and these digital signals are merged and directly sent to a digital signal processing (DSP) chip for processing.

[0071] As an optional embodiment, the wavefront sensor 201 further includes: a front optical lens 207. The front optical lens 207 includes at least one of a beam reducer, a beam expander, and a collimator arranged along the incident optical path of the wavefront to be measured; the front optical lens 207 is coaxially arranged with the semi-reflective semi-transmissive mirror 202, and the front optical lens 207 and the semi-reflective semi-transmissive mirror are arranged in sequence along the incident optical path of the wavefront to be measured.

[0072] Specifically, the front optical lens 207 in the embodiment of the present invention can be used to image the pupil of the wavefront to be measured onto the plane where the semi-reflective semi-lens is located, thereby ensuring the accuracy of wavefront measurement.

[0073] It should be noted that in the embodiment of the present invention, at least one of a beam reducer, a beam expander, and a collimator can be selected based on the actual situation of the wavefront to be measured and the sizes of the first microlens array 203 and the second microlens array 204 as the front optical lens 207.

[0074] It should be noted that in the embodiment of the present invention, at least one of a beam reducer, a beam expander, and a collimator arranged along the incident optical path of the wavefront to be measured means passing through the center point of at least one of a beam reducer, a beam expander, and a collimator along the incident optical path of the wavefront to be measured.

[0075] Among them, a beam reducer can be used to reduce the beam diameter. A beam expander can be used to expand the beam diameter. A collimator can be used to convert a diverging or converging beam into a parallel beam (collimated light), ensuring that the spot displacement is only caused by wavefront distortion rather than beam propagation direction error.

[0076] As an optional embodiment, the front optical lens 207 further includes: a filter arranged along the incident optical path of the wavefront to be measured.

[0077] Specifically, the front optical lens 207 in the embodiment of the present invention may further include a filter arranged along the incident optical path of the wavefront to be measured, and thus the above filter can be used to select light of a specific wavelength and reduce the influence of stray light on wavefront measurement.

[0078] It is understandable that based on the first spot distribution map formed after the reflected wavefront recorded by the first detector 205 passes through the first microlens array 203 and the second spot distribution map formed after the transmitted wavefront recorded by the second detector 206 passes through the second microlens array 204, the wavefront to be measured can be reconstructed through data calculation, mathematical statistics or deep learning technology to obtain the phase information of the wavefront to be measured.

[0079] Specifically, grid division is performed on the first spot distribution map and the second spot distribution map respectively. A target number of grids of the same size are generated in the first spot distribution map, and a target number of grids of the same size are generated in the second spot distribution map. The target number is the total number of each type-I position and each type-II position in the blank matrix.

[0080] Each type-I position and each type-II position in the blank matrix are determined based on the arrangement of each reflection part and each transmission part in the semi-reflective and semi-transmissive mirror 202 of the wavefront sensor 201. The type-I position corresponds to the reflection part, and the type-II position corresponds to the transmission part.

[0081] The blank matrix in the embodiment of the present invention can be expressed by the following formula:

[0082]

[0083] In the blank matrix is a type-I position. Since each reflection part and each transmission part in the semi-reflective and semi-transmissive mirror 202 of the wavefront sensor 201 are alternately arranged in the horizontal direction and the vertical direction, any two type-I positions in the blank matrix are not adjacent.

[0084] Correspondingly, in the blank matrix is a type-II position, and any two type-II positions in the blank matrix are not adjacent.

[0085] Based on the distribution of each type-I position in the blank matrix, the grid corresponding to each type-I position is determined in the first spot distribution map. Based on the distribution of each type-II position in the blank matrix, the grid corresponding to each type-II position is determined in the second spot distribution map.

[0086] Figure 4 is a schematic diagram of the grid corresponding to the type-I position in the first spot distribution map in the wavefront measurement method provided by the present invention. As Figure 4 shown, the type-I position is located in the gray square, which is the grid corresponding to the type-I position in the first spot distribution map.

[0087] For each grid corresponding to each type of position, taking each side of the grid corresponding to each type of position as the hypotenuse, generate right triangles in the direction away from the grid corresponding to each type of position to obtain each right triangle corresponding to each type of position. For each grid corresponding to each second type of position, taking each side of the grid corresponding to each second type of position as the hypotenuse, generate right triangles in the direction away from the grid corresponding to each second type of position to obtain each right triangle corresponding to each second type of position.

[0088] Specifically, as Figure 4 shown, the black right triangles around the grid corresponding to the first type of position are the right triangles corresponding to the first type of position , right triangle , right triangle , right triangle and right triangle .

[0089] Write the position information of the light spots in the areas where the grids corresponding to each type of position and each right triangle in the first light spot distribution map are located to the positions of each type of position in the blank matrix. Write the position information of the light spots in the areas where the grids corresponding to each second type of position and each right triangle in the second light spot distribution map are located to the positions of each second type of position in the blank matrix.

[0090] Specifically, as Figure 4 shown, the position information of the light spots in the area where the grid corresponding to the first type of position and the right triangles corresponding to the first type of position , right triangle , right triangle , right triangle and right triangle are located can be written to the position of the first type of position in the blank matrix.

[0091] It should be noted that in the related art, the dynamic range of the Shack - Hartmann wavefront sensor 201 is the gray area in the first light spot distribution map. When the light spot is not in the gray area, it is impossible to determine which sub - aperture in the microlens array the above - mentioned light spot corresponds to.

[0092] Since the wavefront sensor 201 in the embodiment of the present invention is provided with a semi-reflective and semi-transmissive mirror 202, in the grids on both sides of the grid corresponding to a certain type of position in the first spot distribution map, there are no spots transmitted through the first microlens array 203. In the grids on both sides of the grid corresponding to a certain type of position in the second spot distribution map, there are no spots transmitted through the second microlens array 204. The spots in the regions where each right triangle corresponding to any type of position in the first spot distribution map is located can be determined to belong to the above-mentioned type of position, and the spots in the regions where each right triangle corresponding to any type of position in the second spot distribution map is located can be determined to belong to the above-mentioned type of position, thereby improving the dynamic range of wavefront measurement.

[0093] When the distance between the microlens units in the first microlens array 203 and the second microlens array 204 is x the side length of the grid in the first spot distribution map and the second spot distribution map is x . In the related art, the dynamic range of the Shack-Hartmann wavefront sensor 201 is a square with a side length of x , while the dynamic range of the wavefront sensor 201 in the embodiment of the present invention is extended to a square with as the side length, and the dynamic range area is doubled.

[0094] After obtaining the above target matrix, based on the above target matrix, the first spot distribution map and the second spot distribution map, the wavefront slope matrix of each spot in the first spot distribution map and the wavefront slope matrix of each spot in the second spot distribution map can be calculated respectively. Furthermore, the above two wavefront slope matrices can be combined to obtain a complete wavefront slope matrix.

[0095] Based on the above complete wavefront slope matrix, the wavefront to be measured can be reconstructed to obtain the phase information of the wavefront to be measured.

[0096] The wavefront sensor in the embodiments of the present invention includes a semi-reflective and semi-transmissive mirror, a first microlens array, a second microlens array, a first detector, and a second detector. The incident wavefront to be measured is separated into a reflected wavefront and a transmitted wavefront by the semi-reflective and semi-transmissive mirror. Then, two spot distribution diagrams can be obtained respectively through two sets of identical microlens arrays and detectors, which can significantly improve the measurement ability of the wavefront sensor for high-curvature and large-amplitude wavefront distortions without reducing the sensitivity of the wavefront sensor. By introducing a semi-reflective and semi-transmissive mirror and another set of microlens arrays and detectors, more spot position information can be obtained, the corresponding relationship between the spots and the microlens array can be obtained more accurately, the accuracy of wavefront measurement can be improved, while expanding the dynamic range of the wavefront sensor, excessive hardware complexity is avoided, the feasibility and cost-effectiveness of the wavefront sensor are ensured, the real-time wavefront measurement requirements can be met, the application range of the wavefront sensor is expanded, and the higher requirements for optical measurement can be satisfied.

[0097] Figure 5 It is a schematic flowchart of the wavefront measurement method provided by the present invention. The wavefront measurement method provided by the present invention is implemented based on the above-mentioned wavefront sensor 201. As Figure 5 shown, the method includes the following: Step 501, obtain a first spot distribution diagram and a second spot distribution diagram, and the first spot distribution diagram and the second spot distribution diagram are generated based on the wavefront sensor 201 as described above.

[0098] It should be noted that the execution subject of the embodiments of the present invention is a wavefront measurement device, and the above-mentioned wavefront measurement device can be configured in an electronic device such as a computer or a server.

[0099] It should be noted that the first spot distribution diagram and the second spot distribution diagram in the embodiments of the present invention can be generated based on the wavefront sensor 201 in the above text, and the specific generation methods of the first spot distribution diagram and the second spot distribution diagram in the embodiments of the present invention will not be elaborated herein.

[0100] In the embodiments of the present invention, the first spot distribution diagram and the second spot distribution diagram can be obtained through the interaction of control instructions.

[0101] Step 502, reconstruct the wavefront to be measured based on the first spot distribution diagram and the second spot distribution diagram, and obtain the phase information of the wavefront to be measured.

[0102] Specifically, after obtaining the first spot distribution diagram and the second spot distribution diagram, the wavefront to be measured can be reconstructed based on the first spot distribution diagram and the second spot distribution diagram through methods such as numerical calculation, mathematical statistics, or deep learning technology to obtain the phase information of the wavefront to be measured.

[0103] As an optional embodiment, based on the first spot distribution map and the second spot distribution map, the wavefront to be measured is reconstructed to obtain the phase information of the wavefront to be measured, including: recording the spot positions in the first spot distribution map at a first type of positions in the blank matrix, and recording the spot positions in the second spot distribution map at a second type of positions in the blank matrix, to obtain a target matrix. The first type of positions and the second type of positions in the blank matrix are determined based on the arrangements of the reflection parts and the transmission parts in the semi-reflective and semi-transmissive mirror 202 of the wavefront sensor 201. The first type of positions correspond to the reflection parts, and the second type of positions correspond to the transmission parts.

[0104] Specifically, the blank matrix in the embodiments of the present invention can be expressed by the following formula:

[0105]

[0106] In the blank matrix are the first type of positions. Since the reflection parts and the transmission parts in the semi-reflective and semi-transmissive mirror 202 of the wavefront sensor 201 are arranged alternately in the horizontal direction and the vertical direction, any two first type of positions in the blank matrix are not adjacent.

[0107] Correspondingly, in the blank matrix are the second type of positions, and any two second type of positions in the blank matrix are not adjacent.

[0108] After obtaining the first spot distribution map, based on the distribution of the spots in the first spot distribution map, the first type of position corresponding to each spot can be determined, and then the position of each spot in the first spot distribution map can be recorded at the first type of position corresponding to each spot in the blank matrix.

[0109] Similarly, after obtaining the second spot distribution map, based on the distribution of the spots in the second spot distribution map, the second type of position corresponding to each spot can be determined, and then the position of each spot in the second spot distribution map can be recorded at the second type of position corresponding to each spot in the blank matrix.

[0110] As an optional embodiment, recording the spot positions in the first spot distribution map at the first type of positions in the blank matrix, and recording the spot positions in the second spot distribution map at the second type of positions in the blank matrix, to obtain a target matrix, includes: respectively performing grid division on the first spot distribution map and the second spot distribution map, generating a target number of grids of the same size in the first spot distribution map, and generating a target number of grids of the same size in the second spot distribution map. The target number is the total number of the first type of positions and the second type of positions in the blank matrix.

[0111] Based on the distribution of each first - type position in the blank matrix, determine the grid corresponding to each first - type position in the first spot distribution map. Based on the distribution of each second - type position in the blank matrix, determine the grid corresponding to each second - type position in the second spot distribution map.

[0112] As Figure 4 shown, the gray square where the first - type position is located is the grid corresponding to the first - type position in the first spot distribution map.

[0113] For the grid corresponding to each first - type position, using each side of the grid corresponding to each first - type position as the hypotenuse, generate right - angled triangles in the direction away from the grid corresponding to each first - type position to obtain each right - angled triangle corresponding to each first - type position. For the grid corresponding to each second - type position, using each side of the grid corresponding to each second - type position as the hypotenuse, generate right - angled triangles in the direction away from the grid corresponding to each second - type position to obtain each right - angled triangle corresponding to each second - type position.

[0114] Specifically, as Figure 4 shown, the black right - angled triangles around the grid corresponding to the first - type position are the right - angled triangles corresponding to the first - type position i.e., right - angled triangle , right - angled triangle , right - angled triangle and right - angled triangle .

[0115] Write the position information of the spots in the area of the grid and each right - angled triangle corresponding to each first - type position in the first spot distribution map to the position of each first - type position in the blank matrix. Write the position information of the spots in the area of the grid and each right - angled triangle corresponding to each second - type position in the second spot distribution map to the position of each second - type position in the blank matrix.

[0116] Specifically, as Figure 4 shown, the position information of the spots in the area of the grid corresponding to the first - type position and the right - angled triangles corresponding to the first - type position , right - angled triangle , right - angled triangle and right - angled triangle can be written to the position of the first - type position in the blank matrix.

[0117] It should be noted that the dynamic range of the Shack-Hartmann wavefront sensor 201 in the related art is the gray area in the first spot distribution diagram. When the spot is not in the gray area, it is impossible to determine which sub-aperture in the microlens array the above spot corresponds to.

[0118] Since the wavefront sensor 201 in the embodiment of the present invention is provided with a semi-reflective and semi-transmissive mirror 202, there are no spots transmitted through the first microlens array 203 in the grids on both sides of the grid corresponding to a certain type of position in the first spot distribution diagram, and there are no spots transmitted through the second microlens array 204 in the grids on both sides of the grid corresponding to the second type of position in the second spot distribution diagram. The spots in the area where each right triangle corresponding to any type of position in the first spot distribution diagram is located can be determined to belong to the above type of position, and the spots in the area where each right triangle corresponding to any second type of position in the second spot distribution diagram is located can be determined to belong to the above second type of position, thereby improving the dynamic range of wavefront measurement.

[0119] When the distance between the microlens units in the first microlens array 203 and the second microlens array 204 is x, the side length of the grid in the first spot distribution diagram and the second spot distribution diagram is x. The dynamic range of the Shack-Hartmann wavefront sensor 201 in the related art is a square with a side length of x, while the dynamic range of the wavefront sensor 201 in the embodiment of the present invention is extended to a square with as the side length, and the dynamic range area is doubled.

[0120] Based on the target matrix, the wavefront to be measured is reconstructed to obtain the phase information of the wavefront to be measured.

[0121] Specifically, after obtaining the above target matrix, based on the above target matrix, the first spot distribution diagram and the second spot distribution diagram, the wavefront slope matrix of each spot in the first spot distribution diagram and the wavefront slope matrix of each spot in the second spot distribution diagram can be calculated respectively. Furthermore, the above two wavefront slope matrices can be combined to obtain a complete wavefront slope matrix.

[0122] Based on the above complete wavefront slope matrix, the wavefront to be measured can be reconstructed to obtain the phase information of the wavefront to be measured.

[0123] As an optional embodiment, before obtaining the first spot distribution diagram and the second spot distribution diagram, the method further includes: calibrating the wavefront sensor 201 based on a standard parallel light source to establish the coaxial relationship between the components in the wavefront sensor 201.

[0124] Based on the content of the above embodiments, a wavefront measurement system includes: the wavefront sensor 201 and the electronic device as described above; the electronic device is electrically connected to the first detector 205 and the second detector 206 in the wavefront sensor 201 respectively.

[0125] The electronic device is configured to obtain the first spot distribution map recorded by the first detector 205 and the second spot distribution map recorded by the second eye sidewall, and then reconstruct the wavefront to be measured based on the first spot distribution map and the second spot distribution map to obtain the phase information of the wavefront to be measured.

[0126] The wavefront measurement system provided by the present invention, through the semi-reflective semi-transmissive mirror and the optimized data processing flow, significantly improves the measurement ability of high curvature and large-amplitude wavefront distortion on the basis of not significantly increasing the system complexity, improves the accuracy of wavefront measurement, can obtain the distribution images of all spots in one exposure, can complete wavefront reconstruction without multiple exposures and complicated algorithms, can save a large amount of measurement time, improves the efficiency of wavefront measurement, can meet the real-time wavefront measurement requirements, expands the application range of the wavefront sensor, ensures the feasibility and cost-effectiveness of wavefront measurement, and can meet the higher requirements of optical measurement.

[0127] Figure 6 An example of the physical structure diagram of an electronic device is shown as Figure 6 As shown, the electronic device may include: a processor 610, a communications interface 620, a memory 630, and a communication bus 640. Among them, the processor 610, the communications interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call the logical instructions in the memory 630 to execute the wavefront measurement method, which includes: obtaining the first spot distribution map and the second spot distribution map, where the first spot distribution map and the second spot distribution map are generated based on the above wavefront sensor; reconstructing the wavefront to be measured based on the first spot distribution map and the second spot distribution map to obtain the phase information of the wavefront to be measured.

[0128] In addition, when the logical instructions in the above-mentioned memory 630 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0129] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the wavefront measurement method provided by each of the above methods. The method includes: obtaining a first spot distribution map and a second spot distribution map, where the first spot distribution map and the second spot distribution map are generated based on the above-mentioned wavefront sensor; based on the first spot distribution map and the second spot distribution map, reconstructing the wavefront to be measured to obtain the phase information of the wavefront to be measured.

[0130] In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the wavefront measurement method provided by each of the above methods. The method includes: obtaining a first spot distribution map and a second spot distribution map, where the first spot distribution map and the second spot distribution map are generated based on the above-mentioned wavefront sensor; based on the first spot distribution map and the second spot distribution map, reconstructing the wavefront to be measured to obtain the phase information of the wavefront to be measured.

[0131] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0132] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wavefront sensor, characterized in that: include: A semi-reflective and semi-transmissive mirror, a first microlens array, a second microlens array, a first detector and a second detector; The first microlens array and the second microlens array are the same microlens array; the first detector and the second detector are the same detector; The semi-reflective and semi-transmissive mirror is composed of a plurality of reflective parts and a plurality of transmissive parts, the reflective parts and the transmissive parts are both rectangular and have equal areas, the reflective parts and the transmissive parts are alternately arranged in the horizontal direction and the vertical direction, and the semi-reflective and semi-transmissive mirror is used to separate the incident wavefront to be measured into a reflected wavefront and a transmitted wavefront; The first microlens array is perpendicular to the reflection light path of the semi-reflective and semi-transmissive mirror and is arranged on the focal plane of the reflection light path of the semi-reflective and semi-transmissive mirror; The second microlens array is perpendicular to the transmission light path of the semi-reflective and semi-transmissive mirror and is arranged on the focal plane of the transmission light path of the semi-reflective and semi-transmissive mirror; The first detector is coaxially arranged with the first microlens array, and the first detector is used to record a first light spot distribution diagram formed after the reflected wavefront passes through the first microlens array; The second detector is coaxially arranged with the second microlens array, and is used for recording a second light spot distribution diagram formed after the transmitted wavefront passes through the second microlens array, so that the electronic device can reconstruct the wavefront to be measured based on the first light spot distribution diagram and the second light spot distribution diagram to obtain the phase information of the wavefront to be measured.

2. The wavefront sensor according to claim 1, characterized in that: Also includes: A front optical lens; the front optical lens comprises at least one of a beam reducer, a beam expander and a collimator arranged along the incident light path of the wavefront to be measured; The front optical lens is coaxially arranged with the semi-reflective and semi-transmissive mirror, and the front optical lens and the semi-reflective and semi-transmissive mirror are arranged in sequence along the incident light path of the wavefront to be measured.

3. The wavefront sensor according to claim 2, characterized in that: The front optical lens further includes: a filter arranged along the incident light path of the wavefront to be measured.

4. The wavefront sensor according to any one of claims 1 to 3, characterized in that: The first detector and the second detector are both high-speed charge-coupled device (CCD) detectors or complementary metal oxide semiconductor (CMOS) detectors.

5. A wavefront measurement method, characterized in that: include: Acquire a first light spot distribution map and a second light spot distribution map, wherein the first light spot distribution map and the second light spot distribution map are generated based on the wavefront sensor according to any one of claims 1 to 4; The wavefront to be measured is reconstructed based on the first light spot distribution map and the second light spot distribution map to obtain phase information of the wavefront to be measured.

6. The wavefront measurement method according to claim 5, characterized in that: The reconstructing the wavefront to be measured based on the first light spot distribution map and the second light spot distribution map to obtain the phase information of the wavefront to be measured includes: Record the light spot positions in the first light spot distribution map at a type-one position in a blank matrix, and record the light spot positions in the second light spot distribution map at a type-two position in the blank matrix, to obtain a target matrix, wherein each of the type-one position and each of the type-two positions in the blank matrix is ​​determined based on the arrangement of each reflecting part and each transmitting part in the semi-reflective and semi-transmissive mirror in the wavefront sensor, wherein the type-one position corresponds to the reflecting part, and the type-two position corresponds to the transmitting part; Based on the target matrix, the wavefront to be measured is reconstructed to obtain phase information of the wavefront to be measured.

7. The wavefront measurement method according to claim 6, characterized in that: The step of recording the light spot positions in the first light spot distribution map at a first type of position in a blank matrix and recording the light spot positions in the second light spot distribution map at a second type of position in the blank matrix to obtain a target matrix comprises: Performing grid division on the first spot distribution map and the second spot distribution map respectively, generating a target number of grids of the same size in the first spot distribution map, and generating a target number of grids of the same size in the second spot distribution map, wherein the target number is the total number of each of the first type of positions and each of the second type of positions in the blank matrix; Based on the distribution of each of the first type of positions in the blank matrix, determine the grid corresponding to each of the first type of positions in the first light spot distribution map; based on the distribution of each of the second type of positions in the blank matrix, determine the grid corresponding to each of the second type of positions in the second light spot distribution map; For each grid corresponding to the first type of position, a right triangle is generated in a direction away from the grid corresponding to the first type of position with each side of the grid corresponding to the first type of position as a hypotenuse, so as to obtain each right triangle corresponding to the first type of position; for each grid corresponding to the second type of position, a right triangle is generated in a direction away from the grid corresponding to the second type of position with each side of the grid corresponding to the second type of position as a hypotenuse, so as to obtain each right triangle corresponding to the second type of position; The grids corresponding to each type of position in the first light spot distribution diagram and the position information of the light spots in the area where each right triangle is located are written into each type of position in the blank matrix, and the grids corresponding to each type of position in the second light spot distribution diagram and the position information of the light spots in the area where each right triangle is located are written into each type of position in the blank matrix.

8. The wavefront measurement method according to any one of claims 5 to 7, characterized in that: Before acquiring the first light spot distribution map and the second light spot distribution map, the method further includes: The wavefront sensor is calibrated based on a standard parallel light source, and a coaxial relationship between components in the wavefront sensor is established.

9. A wavefront measurement system, characterized in that: include: The wavefront sensor and electronic device according to any one of claims 1 to 4; the electronic device is electrically connected to the first detector and the second detector in the wavefront sensor respectively; The electronic device is used to reconstruct the wavefront to be measured based on the first light spot distribution map and the second light spot distribution map to obtain phase information of the wavefront to be measured.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the wavefront measurement method according to any one of claims 5 to 8 is implemented.

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