A high-sensitivity waveform reconstruction method and device

Abstract

The present invention discloses a highly sensitive waveform reconstruction method and device. The method is applicable to a case where the focal plane of a CCD to be detected is provided with a plurality of collection areas, each collection area having at least one microlens aperture area. The method comprises: extracting the current centroid position coordinates from the microlens aperture areas contained in each collection area to obtain a plurality of current centroid position coordinates; calculating the position difference between each current centroid position coordinate and the corresponding ideal centroid position coordinate; facilitating the calculation of the restored wavefront phase of the waveform using the position difference; and substituting the restored wavefront phase into a waveform reconstruction algorithm to reconstruct the waveform. The present invention can effectively improve the accuracy of the reconstructed waveform and reduce the error caused by the deformed waveform. It can also improve the sensitivity and detection range of the wavefront detection. In addition, by blocking part of the centroid position to extract other centroid positions, the method of extracting the centroid of the light spot can also be simplified, thereby improving the accuracy of the centroid extraction.

Description

Technical Field

[0001] The present invention relates to the technical field of wavefront reconstruction, and in particular to a high-sensitivity waveform reconstruction method and device. Background Art

[0002] Wavefront detection is one of the core components of the adaptive optics system and directly determines the overall performance of the adaptive optics system.

[0003] The current main detection method is to use a Shack-Hartmann wavefront detector, which is mainly composed of a microlens array and a high-speed CCD. During detection, the detection wavefront is divided by the microlens array and focused onto the CCD focal plane. The center of mass of the light spot on the focal plane is then determined. Finally, the detection wavefront can be obtained based on the wavefront reconstruction algorithm and the center of mass position.

[0004] However, currently used detection methods have the following technical issues: When the detected wavefront is distorted, the spot distribution on the CCD focal plane also deviates from the ideal position, resulting in an irregular spot distribution. When the distorted wavefront is significantly deformed, the centroid of the spot may exceed the size of the microlens aperture or the positions of the centroids may overlap. Directly capturing the centroid position for waveform reconstruction results in a large error between the detected wavefront and the actual wavefront, resulting in low accuracy. Summary of the Invention

[0005] The present invention proposes a highly sensitive waveform reconstruction method and device, which can extract different center of mass positions multiple times, calculate the offset between the center of mass position and the ideal center of mass position, and perform wavefront reconstruction based on the offset to reduce the error of the reconstructed waveform and improve the accuracy of the constructed waveform.

[0006] A first aspect of an embodiment of the present invention provides a high-sensitivity waveform reconstruction method, which is applicable to a CCD focal plane to be detected, wherein the focal plane is provided with a plurality of set areas, each of which has at least one microlens aperture area. The method comprises:

[0007] Extracting the current centroid position coordinates from the microlens aperture area included in each of the set areas to obtain a plurality of current centroid position coordinates;

[0008] Calculating the position difference between each current center of mass position coordinate and the corresponding ideal center of mass position coordinate;

[0009] It is beneficial to calculate the restored wavefront phase of the waveform by the position difference;

[0010] The restored wavefront phase is substituted into the waveform reconstruction algorithm to reconstruct the waveform.

[0011] In a possible implementation of the first aspect, the position difference is calculated as shown in the following formula:

[0012]

[0013]

[0014] in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW x is the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

[0015] In a possible implementation of the first aspect, the calculation of the restored wavefront phase is shown in the following formula:

[0016]

[0017] Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

[0018] In a possible implementation of the first aspect, extracting the current centroid position coordinates from the microlens aperture area included in each of the set areas to obtain multiple current centroid position coordinates includes:

[0019] Selecting a set region to be extracted from the plurality of set regions in sequence, and blocking a plurality of non-extracted set regions;

[0020] Extracting the current centroid position coordinates from the microlens aperture area contained in each of the set areas to be extracted;

[0021] The current centroid position coordinates corresponding to each of the set areas to be extracted are overlapped on the CCD focal plane to obtain a plurality of current centroid position coordinates.

[0022] A second aspect of an embodiment of the present invention provides a highly sensitive waveform reconstruction device, wherein the device is adapted to detect a CCD focal plane having a plurality of collection areas, each collection area having at least one microlens aperture area, and the device comprises:

[0023] an extraction module, configured to extract the current centroid position coordinates from the microlens aperture area contained in each of the set areas to obtain a plurality of current centroid position coordinates;

[0024] A calculation module, configured to calculate the position difference between each of the current center of mass position coordinates and the corresponding ideal center of mass position coordinates;

[0025] A restoration module, configured to facilitate calculation of the position difference to restore the wavefront phase of the waveform;

[0026] The reconstruction module is used to substitute the restored wavefront phase into the waveform reconstruction algorithm to reconstruct the waveform.

[0027] In a possible implementation manner of the second aspect, the position difference is calculated as shown in the following formula:

[0028]

[0029]

[0030] in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW x is the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

[0031] In a possible implementation of the second aspect, the calculation of the restored wavefront phase is shown in the following formula:

[0032]

[0033] Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

[0034] In a possible implementation of the second aspect, the extraction module is further configured to:

[0035] Selecting a set region to be extracted from the plurality of set regions in sequence, and blocking a plurality of non-extracted set regions;

[0036] Extracting the current centroid position coordinates from the microlens aperture area contained in each of the set areas to be extracted;

[0037] The current centroid position coordinates corresponding to each of the set areas to be extracted are overlapped on the CCD focal plane to obtain a plurality of current centroid position coordinates.

[0038] Compared with the prior art, the embodiments of the present invention provide a highly sensitive waveform reconstruction method and device, which have the following beneficial effects: the present invention can calculate the position difference between each centroid position and its corresponding ideal centroid position, which is beneficial to the position difference calculation of the restored wavefront phase of the waveform. When the restored wavefront phase is substituted into the reconstruction waveform algorithm to reconstruct the waveform, the accuracy of the reconstructed waveform can be effectively improved, and the error caused by the deformed waveform can be reduced. At the same time, the sensitivity and detection range of the wavefront detection can also be improved. In addition, by blocking part of the centroid position to extract other centroid positions, the spot centroid extraction method can also be simplified, thereby improving the accuracy of the centroid extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of a microlens array provided by one embodiment of the present invention;

[0040] Figure 2 1 is a structural diagram of light spot distribution provided by an embodiment of the present invention;

[0041] Figure 3 This is a flow chart of a high-sensitivity waveform reconstruction method provided by one embodiment of the present invention;

[0042] Figure 4 1 is a schematic structural diagram of a CCD focal plane provided by an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the structure of the set area to be extracted and the set area not to be extracted provided by an embodiment of the present invention. Figure 1 ;

[0044] Figure 6 This is a schematic diagram of the structure of the set area to be extracted and the set area not to be extracted provided by an embodiment of the present invention. Figure 2 ;

[0045] Figure 7 1 is a schematic structural diagram of the current centroid position coordinates after overlapping provided by an embodiment of the present invention;

[0046] Figure 8 It is a structural schematic diagram of a high-sensitivity waveform reconstruction device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe 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.

[0048] The current main detection method is to use a Shack-Hartmann wavefront detector, which is mainly composed of a microlens array and a high-speed CCD. During detection, the detection wavefront is divided by the microlens array and focused onto the CCD focal plane. The center of mass of the light spot on the focal plane is then determined. Finally, the detection wavefront can be obtained based on the wavefront reconstruction algorithm and the center of mass position.

[0049] Specifically, refer to Figure 1-2 , respectively showing a structural schematic diagram of a microlens array provided by an embodiment of the present invention and a structural schematic diagram of a light spot distribution provided by an embodiment of the present invention.

[0050] Reference Figure 1-2 It can be seen that the currently used detection method has the following technical problems: once the detection wavefront is distorted, the spot distribution on the CCD focal plane also deviates from the ideal position, resulting in an irregular spot distribution. When the distorted wavefront is significantly deformed, the center of mass of the spot may exceed the size of the microlens aperture or the positions of the individual center of mass may overlap and intersect. If the center of mass position is directly collected to reconstruct the waveform, the error between the detected wavefront and the actual wavefront will be large, and the accuracy will be low.

[0051] In order to solve the above problems, a high-sensitivity waveform reconstruction method provided by the embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0052] Reference Figure 3-4 , respectively showing a flow chart of a high-sensitivity waveform reconstruction method provided by an embodiment of the present invention.

[0053] In this embodiment, the high-sensitivity waveform reconstruction method is applicable when the CCD focal plane to be detected is provided with a plurality of collection areas, and each collection area has at least one microlens aperture area.

[0054] Specifically, refer to Figure 4 In an optional embodiment, the CCD focal plane is provided with four microlens aperture areas, namely ①, ②, ③, and ④; the two microlens aperture areas ① and ④ can be used as a collection area, and the two microlens aperture areas ② and ③ can be used as another collection area.

[0055] As an example, the high-sensitivity waveform reconstruction method may include:

[0056] S11. Extract the current centroid position coordinates from the microlens aperture area included in each of the set areas to obtain a plurality of current centroid position coordinates.

[0057] In actual operation, by dividing the collection areas at different heights and extracting the centroid position coordinates of the light spots within the area, the centroids of adjacent light spots can be avoided from being confused, thereby improving the accuracy of the acquisition.

[0058] As described above, when the detected wavefront is a distorted detection wavefront, the spot distribution on the CCD focal plane not only deviates from the ideal position, but also the centroids of adjacent or different spots overlap and intersect with each other. For example, the centroid of spot a is distributed in the microlens aperture area of ​​spot d, misleading the user into thinking that the centroid of the microlens aperture area of ​​spot d is the same as that of spot d.

[0059] To avoid the above situation, as an example, step S11 may include the following sub-steps:

[0060] S111 , sequentially selecting a set region to be extracted from the plurality of set regions, and blocking a plurality of non-extracted set regions.

[0061] S112. Extract the current centroid position coordinates from the microlens aperture area included in each of the set areas to be extracted.

[0062] S113 , overlapping the current centroid position coordinates corresponding to each of the set areas to be extracted on the CCD focal plane to obtain a plurality of current centroid position coordinates.

[0063] Specifically, Figure 4 The four microlens aperture areas are used as an actual example to illustrate.

[0064] Reference Figure 5-7 , respectively showing the structure of the set area to be extracted and the set area not to be extracted provided by an embodiment of the present invention Figure 1 , a schematic diagram of the structure of the set area to be extracted and the set area not to be extracted provided by an embodiment of the present invention Figure 2 and a schematic structural diagram of the current centroid position coordinates after overlapping provided by an embodiment of the present invention.

[0065] In actual operation, the two micro-holes ② and ③ can be blocked, and the two holes ① and ④ can be transparent, so that the light spot can be located in the micro-lens aperture area of ​​① and ④ or the micro-lens aperture area near them, and then the distorted wavefront light spot and the center of mass position of the light spot can be recorded. Figure 5 As shown;

[0066] Then, block the two micro-holes ① and ④, and let the two micro-holes ②③② and ③ pass through. Record the distorted wavefront spot and the centroid position of the spot at this time, as shown in the following figure: Figure 6 As shown;

[0067] Finally, the two sets of centroid positions are spliced ​​together, such as Figure 7 shown.

[0068] Through the above operation method, it is possible to avoid misleading the user due to the centroid being located in different microlens aperture areas, and further improve the accuracy of subsequent reconstruction.

[0069] S12. Calculate the position difference between each current center of mass position coordinate and the corresponding ideal center of mass position coordinate.

[0070] Specifically, the position of each centroid and the center position of the microlens aperture area in which it is located (the ideal position of the centroid) are calculated respectively.

[0071] In an optional embodiment, the position difference is calculated as follows:

[0072]

[0073]

[0074] in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW x is the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

[0075] S13, facilitating calculation of the position difference to restore the wavefront phase of the waveform.

[0076] In one embodiment, the calculation of the restored wavefront phase is shown as follows:

[0077]

[0078] Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

[0079] S14. Substitute the restored wavefront phase into a waveform reconstruction algorithm to reconstruct a waveform.

[0080] In this embodiment, the embodiment of the present invention provides a high-sensitivity waveform reconstruction method, which has the beneficial effect of: the present invention can calculate the position difference between each centroid position and its corresponding ideal centroid position, which is beneficial to the position difference calculation of the restored wavefront phase of the waveform, and when the restored wavefront phase is substituted into the reconstruction waveform algorithm to reconstruct the waveform, it can effectively improve the accuracy of the reconstructed waveform, reduce the error caused by the deformed waveform, and also improve the sensitivity and detection range of the wavefront detection. In addition, by blocking part of the centroid position to extract other centroid positions, the spot centroid extraction method can also be simplified, thereby improving the accuracy of the centroid extraction.

[0081] The embodiment of the present invention also provides a high-sensitivity waveform reconstruction device, see Figure 8 , which shows a structural schematic diagram of a high-sensitivity waveform reconstruction device provided by an embodiment of the present invention.

[0082] The device is suitable for detecting a CCD focal plane provided with a plurality of collection areas, and each combination area has at least one microlens aperture area.

[0083] As an example, the high-sensitivity waveform reconstruction device may include:

[0084] An extraction module 801 is configured to extract the current centroid position coordinates from the microlens aperture area contained in each of the set areas to obtain a plurality of current centroid position coordinates;

[0085] A calculation module 802 is configured to calculate a position difference between each of the current mass center position coordinates and the corresponding ideal mass center position coordinates;

[0086] Restoration module 803, used to facilitate the calculation of the position difference waveform to restore the wavefront phase;

[0087] The reconstruction module 804 is used to substitute the restored wavefront phase into the waveform reconstruction algorithm to reconstruct the waveform.

[0088] Optionally, the position difference is calculated as shown in the following formula:

[0089]

[0090]

[0091] in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW xis the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

[0092] Optionally, the calculation of the restored wavefront phase is shown in the following formula:

[0093]

[0094] Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

[0095] Optionally, the extraction module is further configured to:

[0096] Selecting a set region to be extracted from the plurality of set regions in sequence, and blocking a plurality of non-extracted set regions;

[0097] Extracting the current centroid position coordinates from the microlens aperture area contained in each of the set areas to be extracted;

[0098] The current centroid position coordinates corresponding to each of the set areas to be extracted are overlapped on the CCD focal plane to obtain a plurality of current centroid position coordinates.

[0099] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0100] Furthermore, an embodiment of the present application also provides 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 program, the high-sensitivity waveform reconstruction method as described in the above embodiment is implemented.

[0101] Furthermore, an embodiment of the present application also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the high-sensitivity waveform reconstruction method described in the above embodiment.

[0102] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high-sensitivity waveform reconstruction method, characterized in that: The method is applicable to a case where the CCD focal plane to be detected is provided with a plurality of collection areas, each collection area having at least one microlens aperture area, and the method comprises: Extracting the current centroid position coordinates from the microlens aperture area included in each of the set areas to obtain a plurality of current centroid position coordinates; Calculating the position difference between each current center of mass position coordinate and the corresponding ideal center of mass position coordinate; Calculating the restored wavefront phase of the waveform using the position difference; Substituting the restored wavefront phase into a waveform reconstruction algorithm to reconstruct a waveform; The current centroid position coordinates are extracted from the microlens aperture area included in each of the set areas to obtain multiple current centroid position coordinates, including: Selecting a set region to be extracted from the plurality of set regions in sequence, and blocking a plurality of non-extracted set regions; Extracting the current centroid position coordinates from the microlens aperture area contained in each of the set areas to be extracted; The current centroid position coordinates corresponding to each of the set areas to be extracted are overlapped on the CCD focal plane to obtain a plurality of current centroid position coordinates.

2. The high-sensitivity waveform reconstruction method according to claim 1, characterized in that: The position difference is calculated as follows: in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW x is the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

3. The high-sensitivity waveform reconstruction method according to claim 1, characterized in that: The calculation of the restored wavefront phase is shown in the following formula: Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

4. A highly sensitive waveform reconstruction device, characterized in that: The device is suitable for detecting a CCD focal plane with a plurality of collection areas, each collection area having at least one microlens aperture area, and the device comprises: an extraction module, configured to extract the current centroid position coordinates from the microlens aperture area contained in each of the set areas to obtain a plurality of current centroid position coordinates; A calculation module, configured to calculate the position difference between each of the current center of mass position coordinates and the corresponding ideal center of mass position coordinates; A restoration module, configured to calculate a restored wavefront phase of the waveform using the position difference; A reconstruction module, used for substituting the restored wavefront phase into a waveform reconstruction algorithm to reconstruct a waveform; The extraction module is further configured to: Selecting a set region to be extracted from the plurality of set regions in sequence, and blocking a plurality of non-extracted set regions; Extracting the current centroid position coordinates from the microlens aperture area contained in each of the set areas to be extracted; The current centroid position coordinates corresponding to each of the set areas to be extracted are overlapped on the CCD focal plane to obtain a plurality of current centroid position coordinates.

5. The high-sensitivity waveform reconstruction device according to claim 4, characterized in that: The position difference is calculated as follows: in, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, ΔW x is the offset distance of the incident wavefront in the x-axis direction, ΔW y is the offset distance of the incident wavefront in the y-axis direction, S x is the wavefront slope in the x-axis direction, S y is the wavefront slope in the y-axis direction, f represents the focal length of the lens, D is the diameter of the aperture area of ​​a single microlens, △x is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the x-direction after the incident wavefront passes through the microaperture, and △y is the offset of the center of mass of the distorted light spot relative to the center of mass of the ideal light spot in the y-direction after the incident wavefront passes through the microaperture.

6. The high-sensitivity waveform reconstruction device according to claim 4, characterized in that: The calculation of the restored wavefront phase is shown below: Where ΔW(x,y) is the actual wavefront phase, is the X-axis direction of the incident wavefront, is the y-axis direction of the incident wavefront, i is the unit vector in the x-direction, and j is the unit vector in the y-direction.

7. 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 program, the high-sensitivity waveform reconstruction method according to any one of claims 1 to 3 is implemented.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the high-sensitivity waveform reconstruction method according to any one of claims 1 to 3.

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