A wavefront restoration method, system, device and storage medium

Abstract

The present invention discloses a wavefront restoration method, system, device and storage medium. During random diffusion, there is only a certain probability of diffusion each time, which avoids the accumulation of errors in one direction when recovering data containing measurement errors, resulting in stripes in one direction in the restored phase diagram; the phase is recorded as a complex number, and a difference of 2π corresponds to the same value, which avoids the problems caused by the restoration of vortex light; the argument of the sum of the complex numbers is taken in multiple restorations, which can reduce the deviation of a single wavefront restoration; more importantly, the present invention does not involve sparse matrix operations and is easy to write.

Description

Technical Field

[0001] The present invention relates to the field of optical information measurement technology, and in particular to a wavefront restoration method, system, device and storage medium. Background Art

[0002] A wavefront sensor is a modern optical measuring instrument that can measure phase information of light that is difficult to measure. It is mainly used to correct wavefront distortion in adaptive optics.

[0003] The most common Shack-Hartmann wavefront sensor in wavefront sensing or the wavefront sensor based on quantum weak measurement invented by the University of Science and Technology of China directly measures the wavefront gradient at discrete points in space, and a wavefront restoration algorithm is required to restore the wavefront phase.

[0004] Currently, common wavefront restoration algorithms include the regional method and the pattern method; however, they both involve sparse matrix operations, which not only increases the difficulty of algorithm writing, but also cannot properly restore vortex light with phase singularities, such as the beam with parameter l greater than 0 in the Laguerre-Gaussian mode. Summary of the Invention

[0005] The purpose of the present invention is to provide a wavefront restoration method, system, device and storage medium, which are based on random diffusion and use complex numbers to record phase values, and can restore a variety of wavefronts. It is particularly suitable for phase reconstruction of wavefronts with phase singularities, such as vortex light, and the restoration scheme is easy to write.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A wavefront restoration method, comprising:

[0008] Step S1, using a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region;

[0009] Step S2: Randomly select a point as the starting point. The starting point is the calculated point, and its phase value is recorded as 0. The remaining points are uncalculated points.

[0010] Step S3: List all currently calculated points and check whether the four points above, below, to the left, and to the right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; if they do, calculate the phase value of the corresponding point according to the set probability; when all calculated points have been checked and no point meets the calculation conditions, go to step S4, otherwise repeat step S3;

[0011] Step S4: Subtract the phase value of the preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value as a complex number;

[0012] Step S5: Repeat steps S2, S3, and S4 until the set number of times is reached, add the complex numbers recorded at each calculated point, and take the argument of the sum as the final phase value of the corresponding calculated point.

[0013] A wavefront restoration system, comprising:

[0014] The information acquisition unit is configured to execute step S1: using a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region;

[0015] The wavefront phase image restoration unit is used to perform the following steps: step S2, randomly select a point as the starting point, the starting point is used as the calculated point, its phase value is recorded as 0, and the remaining points are uncalculated points; step S3, list all currently calculated points, and check whether the four points above, below, left and right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; if they meet the conditions, the corresponding point is calculated according to the set probability. When all calculated points have been checked and there are no points that meet the calculation conditions, go to step S4, otherwise repeat step S3; step S4, subtract the phase value of a preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value using a complex number; step S5, repeat steps S2, S3 and S4 until the set number of times is reached, add the complex numbers recorded each time for each calculated point, and take the argument of the sum as the final phase value of the corresponding calculated point.

[0016] A processing device comprising: one or more processors; a memory for storing one or more programs;

[0017] When the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method.

[0018] A readable storage medium stores a computer program, which implements the aforementioned method when the computer program is executed by a processor.

[0019] It can be seen from the technical solution provided by the present invention that random diffusion occurs with only a certain probability each time, which avoids the accumulation of errors in one direction when recovering data containing measurement errors, resulting in stripes in one direction in the restored phase diagram; the phase is recorded as a complex number, and a difference of 2π corresponds to the same value, which avoids the problems caused by the restoration of vortex light; the angle of the sum of the complex numbers is taken for multiple restorations, which can reduce the deviation of a single wavefront restoration; more importantly, the present invention does not involve sparse matrix operations and is easy to write. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A flow chart of a wavefront restoration method provided by an embodiment of the present invention;

[0022] Figure 2 A horizontal slope diagram of the vortex phase light numerically simulated according to an embodiment of the present invention;

[0023] Figure 3 A vertical slope diagram of the vortex phase light numerically simulated according to an embodiment of the present invention;

[0024] Figure 4 The basis provided by the embodiment of the present invention Figure 2 and Figure 3 The wavefront phase image restored from the slope information;

[0025] Figure 5 A horizontal slope diagram of the vortex phase light measured by a wavefront sensor based on quantum weak measurement provided by an embodiment of the present invention;

[0026] Figure 6 A vertical slope diagram of vortex phase light measured by a wavefront sensor based on quantum weak measurement provided by an embodiment of the present invention;

[0027] Figure 7 The basis provided by the embodiment of the present invention Figure 5 and Figure 6 The wavefront phase image restored from the slope information;

[0028] Figure 8 A schematic diagram of a wavefront restoration system provided by an embodiment of the present invention;

[0029] Figure 9 A schematic diagram of a processing device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] First, the following terms may be used in this article:

[0032] The terms "include," "comprises," "contains," "has," or other similar expressions should be interpreted as non-exclusive. For example, "including certain technical features (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products, or manufactured articles, etc.) should be interpreted as including not only the technical features explicitly listed, but also other technical features known in the art that are not explicitly listed.

[0033] The following describes a wavefront restoration solution provided by the present invention in detail. Any details not described in the examples of the present invention are prior art known to those skilled in the art. For any conditions not specified in the examples of the present invention, the procedures were performed according to conventional conditions in the art or the conditions recommended by the manufacturer. For any reagents or instruments used in the examples of the present invention, for which the manufacturer is not specified, all are commercially available conventional products.

[0034] Example 1

[0035] like Figure 1 As shown, a wavefront restoration method mainly includes the following steps:

[0036] Step S1: Use a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region.

[0037] In an embodiment of the present invention, the wavefront sensor may be a Shack-Hartmann wavefront sensor, a wavefront sensor based on quantum weak measurement, or other wavefront sensors that can measure wavefront phase gradient distribution.

[0038] In the embodiment of the present invention, the spatial region is a square grid region, and the goal is to detect the wavefront at each point in the spatial region.

[0039] Step S2: Randomly select a point as the starting point. The starting point is the calculated point, and its phase value is recorded as 0. The remaining points are uncalculated points.

[0040] Step S3: List all currently calculated points and check whether the four points above, below, left, and right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; if they meet the conditions, the phase value of the corresponding point is calculated according to the set probability.

[0041] In the embodiment of the present invention, the calculated point position is recorded as (i, j), and the phase value is recorded as Wavefront phase gradient k x With k y The distribution at position (i, j) is recorded as kx；i,j With k y；i,j ; When calculating the phase value, different methods are used for points at different positions:

[0042] If it is the upper point, the phase value calculation formula is:

[0043] If it is the lower point, the phase value calculation formula is:

[0044] If it is the left point, the phase value calculation formula is:

[0045] If it is the right point, the phase value calculation formula is:

[0046] Where h is the grid unit length, k x is the x-direction partial derivative of the wavefront phase, k y is the y-direction partial derivative of the wavefront phase, i and j are the horizontal and vertical position numbers in the square grid area, respectively.

[0047] For example, points that meet the conditions may be subjected to phase calculation with a probability of 1 / 2.

[0048] In this step, when all calculated points have been checked and there are no points that meet the calculation conditions, the process proceeds to step S4, otherwise, step S3 is repeated.

[0049] Step S4: Subtract the phase value of the preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value as a complex number.

[0050] In the embodiment of the present invention, a fixed point is pre-selected as a reference zero phase point, and the phase value of the fixed point obtained by this calculation is recorded as The phase value of the calculated point at position (i, j) is recorded as The phase value and After subtraction, the complex number record is expressed as: Among them, e represents a natural constant and the positive form i is an imaginary unit.

[0051] Step S5: Repeat steps S2, S3, and S4 until the set number of times is reached, add the complex numbers recorded at each point, and take the argument of the sum as the final phase value of the corresponding point.

[0052] In the embodiment of the present invention, each time step S2, step S3 and step S4 are repeatedly executed, the order of listing all currently calculated points is different and may be a random order.

[0053] In the embodiment of the present invention, there is no limit on the number of repetitions; however, in order to ensure the recovery effect, the number of repetitions is usually more than 100 times.

[0054] The above-mentioned solution of the embodiment of the present invention can solve the problems existing in the prior art that conventional algorithms cannot normally restore vortex light with phase singularities and are difficult to write; the beneficial effects obtained include: random diffusion has only a certain probability of diffusion each time, which avoids the accumulation of errors in one direction when recovering data containing measurement errors, resulting in stripes in one direction in the restored phase diagram; the phase is recorded as a complex number, and a difference of 2π corresponds to the same value, which avoids the problems caused by the restoration of vortex light. The multiple restorations take the angle of the sum of the complex numbers to reduce the deviation of the single wavefront restoration. More importantly, the present invention does not involve sparse matrix operations and is easy to write.

[0055] To facilitate understanding, two examples are given below.

[0056] Example 1

[0057] In this example, the incident laser wavefront used is a Laguerre-Gaussian wavefront with parameter l equal to 1. The simulated wavefront slope distributions in the horizontal and vertical directions are as follows: Figure 2 and Figure 3 As shown, the wavefront slope of the point (pixel) at the (i, j) position is recorded as k x；i,j With k y；i,j , that is, the wavefront phase gradient k x With k y The distribution at position (i, j). Through the above steps S2 to S5, the Laguerre-Gaussian light wavefront can be restored. The reconstructed (recovered) wavefront phase diagram is as follows Figure 4 shown.

[0058] Example 2

[0059] In this example, the incident laser wavefront used is a Laguerre-Gaussian wavefront with parameter l equal to 1. The wavefront slope distributions in the horizontal and vertical directions measured by the weak measurement wavefront sensor are as follows: Figure 5 and Figure 6 As shown, the wavefront phase diagram can be reconstructed through the aforementioned steps S2 to S5, as shown in Figure 7 shown.

[0060] Example 2

[0061] The present invention also provides a wavefront restoration system, which is mainly implemented based on the method provided in the above embodiment. Figure 8 As shown, the system mainly includes:

[0062] The information acquisition unit is configured to execute step S1: using a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region;

[0063] The wavefront phase image restoration unit is used to perform the following steps: step S2, randomly select a point as the starting point, the starting point is used as the calculated point, its phase value is recorded as 0, and the remaining points are uncalculated points; step S3, list all currently calculated points, and check whether the four points above, below, left and right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; if they meet the conditions, the corresponding point is calculated according to the set probability. When all calculated points have been checked and there are no points that meet the calculation conditions, go to step S4, otherwise repeat step S3; step S4, subtract the phase value of a preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value using a complex number; step S5, repeat steps S2, S3 and S4 until the set number of times is reached, add the complex numbers recorded each time for each calculated point, and take the argument of the sum as the final phase value of the corresponding calculated point.

[0064] In an embodiment of the present invention, the wavefront sensor is a Shack-Hartmann wavefront sensor, a wavefront sensor based on quantum weak measurement, or other wavefront sensors that can measure wavefront phase gradient distribution.

[0065] In the embodiment of the present invention, the calculated point position is recorded as (i, j), and the phase value is recorded as Wavefront phase gradient k x With k y The distribution at position (i, j) is recorded as k x；i,j With k y；i,j ; When calculating the phase value, different methods are used for points at different positions:

[0066] If it is the upper point, the phase value calculation formula is:

[0067] If it is the lower point, the phase value calculation formula is:

[0068] If it is the left point, the phase value calculation formula is:

[0069] If it is the right point, the phase value calculation formula is:

[0070] Among them, the spatial area is a square grid area, h is the grid unit length, k x is the x-direction partial derivative of the wavefront phase, k y is the y-direction partial derivative of the wavefront phase, i and j are the horizontal and vertical position numbers in the square grid area, respectively.

[0071] In the embodiment of the present invention, the subtracting the phase value of each calculated point from the phase value of the preset reference zero phase point and recording the calculated phase value using a complex number includes:

[0072] A fixed point is pre-selected as the reference zero phase point. The phase value of this fixed point obtained in this calculation is

[0073] The phase value of the calculated point at position (i, j) is recorded as

[0074] The phase value and After subtraction, the complex number record is expressed as: Among them, e represents a natural constant and the positive form i is an imaginary unit.

[0075] Those skilled in the art will clearly understand that for the convenience and brevity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0076] Example 3

[0077] The present invention also provides a processing device, such as Figure 9 As shown, it mainly includes: one or more processors; a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the method provided by the aforementioned embodiment.

[0078] Furthermore, the processing device further includes at least one input device and at least one output device; in the processing device, the processor, memory, input device, and output device are connected via a bus.

[0079] In the embodiment of the present invention, the specific types of the memory, input device, and output device are not limited; for example:

[0080] The input device can be a touch screen, image acquisition device, physical button or mouse;

[0081] The output device may be a display terminal;

[0082] The memory may be a random access memory (RAM) or a non-volatile memory, such as a disk memory.

[0083] Example 4

[0084] The present invention also provides a readable storage medium storing a computer program, which implements the method provided in the above embodiment when the computer program is executed by a processor.

[0085] In the embodiments of the present invention, the computer-readable storage medium may be provided in the aforementioned processing device, for example, as a memory in the processing device. Alternatively, the computer-readable storage medium may be a USB flash drive, a removable hard drive, a read-only memory (ROM), a magnetic disk, or an optical disk, among other media capable of storing program code.

[0086] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A wavefront restoration method, characterized in that: include: Step S1, using a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region; Step S2: Randomly select a point as the starting point. The starting point is the calculated point, and its phase value is recorded as 0. The remaining points are uncalculated points. Step S3: List all currently calculated points and check whether the four points above, below, left, and right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; If it is satisfied, the phase value of the corresponding point is calculated according to the set probability; when all calculated points are checked and there is no point that meets the calculation conditions, the process goes to step S4, otherwise repeat step S3; the position of the calculated point is recorded as (i, j), and the phase value is recorded as Wavefront phase gradient k x With k y The distribution at position (i, j) is recorded as k x；i,j With k y；i,j ; When calculating the phase value, different methods are used for points at different positions: If it is the upper point, the phase value calculation formula is: If it is the lower point, the phase value calculation formula is: If it is the left point, the phase value calculation formula is: If it is the right point, the phase value calculation formula is: Among them, the spatial area is a square grid area, h is the grid unit length, k x is the x-direction partial derivative of the wavefront phase, k y is the y-direction partial derivative of the wavefront phase, i and j are the serial numbers of the horizontal and vertical positions in the square grid area respectively; Step S4: Subtract the phase value of the preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value as a complex number; Step S5: Repeat steps S2, S3, and S4 until the set number of times is reached, add the complex numbers recorded at each calculated point, and take the argument of the sum as the final phase value of the corresponding calculated point.

2. A wavefront restoration method according to claim 1, characterized in that: The wavefront sensor is a Shack-Hartmann wavefront sensor, a wavefront sensor based on quantum weak measurement, or other wavefront sensors capable of measuring wavefront phase gradient distribution.

3. The wavefront restoration method according to claim 1, characterized in that: The phase value of each calculated point is subtracted from the phase value of the preset reference zero phase point, and the calculated phase value is recorded as a complex number, including: A fixed point is pre-selected as the reference zero phase point, and the phase value of this fixed point obtained by this calculation is recorded as The phase value of the calculated point at position (i, j) is recorded as The phase value and After subtraction, the complex number record is expressed as: Among them, e represents a natural constant and the positive form i is an imaginary unit.

4. A wavefront restoration system, characterized in that: include: The information acquisition unit is configured to execute step S1: using a wavefront sensor to obtain the distribution of the wavefront phase gradient at each point in the spatial region; The wavefront phase image restoration unit is configured to perform the following steps: Step S2, randomly selecting a point as a starting point, wherein the starting point is a calculated point and its phase value is recorded as 0, and the remaining points are uncalculated points; Step S3, listing all currently calculated points and checking whether the four points above, below, to the left, and to the right of each calculated point meet the calculation conditions: they are uncalculated points and are not outside the boundary; If satisfied, the phase value of the corresponding point is calculated according to the set probability; when all calculated points have been checked and there is no point that meets the calculation conditions, go to step S4, otherwise repeat step S3; step S4, subtract the phase value of the preset reference zero phase point from the phase value of each calculated point, and record the calculated phase value using a complex number; step S5, repeat steps S2, S3 and S4 until the set number of times is reached, add the complex numbers recorded each time for each calculated point, and take the argument of the sum as the final phase value of the corresponding calculated point; wherein, the position of the calculated point is recorded as (i, j), and the phase value is recorded as Wavefront phase gradient k x With k y The distribution at position (i, j) is recorded as k x；i,j With k y；i,j ; When calculating the phase value, different methods are used for points at different positions: If it is the upper point, the phase value calculation formula is: If it is the lower point, the phase value calculation formula is: If it is the left point, the phase value calculation formula is: If it is the right point, the phase value calculation formula is: Among them, the spatial area is a square grid area, h is the grid unit length, k x is the x-direction partial derivative of the wavefront phase, k y is the y-direction partial derivative of the wavefront phase, i and j are the horizontal and vertical position numbers in the square grid area, respectively.

5. The wavefront restoration system according to claim 4, characterized in that: The wavefront sensor is a Shack-Hartmann wavefront sensor, a wavefront sensor based on quantum weak measurement, or other wavefront sensors capable of measuring wavefront phase gradient distribution.

6. The wavefront restoration system according to claim 4, characterized in that: The phase value of each calculated point is subtracted from the phase value of the preset reference zero phase point, and the calculated phase value is recorded as a complex number, including: A fixed point is pre-selected as the reference zero phase point, and the phase value of this fixed point obtained by this calculation is recorded as The phase value of the calculated point at position (i, j) is recorded as The phase value and After subtraction, the complex number record is expressed as: Among them, e represents a natural constant and the positive form i is an imaginary unit.

7. A processing device, characterized in that include: one or more processors; a memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 3.

8. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.

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