Method for manufacturing asymmetrically distributed surface micro-hole off-focus lens based on femtosecond laser

Abstract

The application belongs to the technical field of femtosecond laser processing, and particularly relates to a preparation method of an asymmetric distribution surface micropore defocusing lens based on femtosecond laser. The required refractive change in optics is converted into material removal / bulging volume, and then the material volume of each layer processing is controlled by parameters such as laser single-pulse energy, single-point dwell pulse number, scanning speed and interlayer scanning spacing, so as to realize the depth and diameter of the target micropore through layer-by-layer scanning. The processing data of the micropore array is quantized by partitioning, and the quantized data can directly support the femtosecond laser process to realize efficient processing of the micropore array.

Description

Technical Field

[0001] This invention belongs to the field of femtosecond laser processing technology, specifically relating to a method for preparing a defocused lens with asymmetricly distributed surface micropores based on femtosecond lasers. Background Technology

[0002] Defocus lenses are mainly used to control the progression of myopia. They work by adjusting the position of light on the retina to reduce or counteract myopic defocus caused by axial elongation, thereby slowing down the progression of myopia.

[0003] A micro-aperture array is set on the defocused lens to set the defocusing amount. The existing femtosecond laser processing method for micro-apertures has the following drawbacks: Laser irradiation processing: Laser scanning uses a rotationally symmetric path, which cannot realize direct femtosecond laser processing of asymmetric micro-hole arrays; at the same time, existing laser irradiation processing methods are prone to axial misalignment when multi-layer structures are stacked, the single-point scanning method leads to low preparation efficiency, and there is a lack of adaptive scanning algorithms to adapt to multi-layer micro-hole stacking.

[0004] Mold processing: Existing mold manufacturing processes cannot process microholes of different depths. Summary of the Invention

[0005] In view of this, the present invention provides a method for fabricating asymmetric distributed surface micropore defocused lenses based on femtosecond lasers. The method converts the optically required refractive change into material removal / bulging volume, and then controls the material volume of each layer by parameters such as laser single-pulse energy, single-point dwell pulse number, scanning speed and interlayer scanning spacing. Thus, the depth and diameter of the target micropores are achieved by scanning layer by layer. The present invention performs partitioned digital quantization of the micropore array, and the quantized data can directly support the efficient processing of micropore arrays by femtosecond laser technology.

[0006] To achieve the above technical solution, the specific technical solution adopted by the present invention is as follows: A method for fabricating a defocused lens with asymmetricly distributed surface micropores based on femtosecond lasers includes: setting multiple optical zones on the lens; calculating the refractive power of the micropores in each optical zone based on the defocus amount of each optical zone; iteratively optimizing and determining the depth and diameter of the micropores after obtaining the refractive power; then converting the depth and diameter of the micropores into direct-write processing data for femtosecond laser processing; and continuously processing each micropore based on the direct-write processing data. The micropores are processed using a femtosecond laser layer-by-layer scanning method, and the femtosecond laser processing data for the micropores is obtained based on the following formula:

[0007] In the formula, Let be the depth of the micro-hole on the lens at a radius r from the optical center. The material bulging efficiency coefficient of the lens. E For femtosecond laser single pulse energy, The number of dwell pulses per point processed by a femtosecond laser focused spot. The normal scanning distance of the lens during femtosecond laser processing. v The scanning speed of the femtosecond laser spot. is the maximum radius of the lens, and r is the distance between the processed micro-hole and the optical center of the lens; The optical partitioning method includes the following steps: S101: Extract multiple feature regions from the retinal topography of the eyeball, the sum of which covers the fovea centralis or the edge of the optic disc in the retina of the eyeball; S102: Integrate corneal asymmetric morphological factors, retinal characteristic region axial length, and retinal characteristic region curvature data to construct a multi-dimensional biological parameter database; S103: Based on the information in the database, multiple optical zones are set on the lens, and a defocus amount is set for each optical zone to make the lens adapt to the correction defocus amount requirements and anisometropia defocus amount requirements of different areas of the eyeball.

[0008] Furthermore, the depth and diameter of the micropores are calculated based on the following formula:

[0009] in: The refractive power of the micropore; For optical partition (i, j), the positive defocus amount is given. The refractive index of the lens material; The radius of curvature of the lens at a distance r from the optical center; This is the pore size diffraction correction factor for the micropores. , The theoretical focal length of the micropore. ; is the depth gradient coefficient of the micropore; The diameter of the micro-hole located at a radius r from the optical center of the lens; is the diameter gradient coefficient of the micropores.

[0010] Furthermore, in order to achieve continuous processing of each optical zone on the lens, when processing each of the micro-holes, after each zone has completed femtosecond direct-write processing, a white light interferometer is used for detection. The detection result of the white light interferometer is used for: When the depth error of the microhole is >5%, adjust the Z-axis compensation amount when machining the microhole with laser pulse. When the tilt angle deviation of the micro-hole is >2°, adjust the number of circular scans when processing the micro-hole with laser pulse; Generate a topology map of each micropore.

[0011] Furthermore, in order to achieve secondary processing of micropores, when secondary processing of micropores is required, the laser scanning starting point is set on the edge of a polygon 10 μm inside the maximum diameter of the micropore in a plane 10 μm above the bottom layer of the existing micropores, using the topology map as data support; the secondary processing is used to enlarge the diameter of the existing micropores or deepen the depth of the existing micropores.

[0012] Furthermore, in order to improve the adaptability to processing different materials, the wavelength range of the femtosecond laser includes: 1010-1070nm, 510-550nm, 330-350nm and 250-260nm; the single pulse energy of the femtosecond laser is 1-60μJ, the repetition frequency is 20Hz-1MHz, and the average power is 1-30W.

[0013] Furthermore, in order to achieve a non-centrosymmetric processing scanning trajectory, the path planning algorithm used for processing each of the microholes is an Archimedean spiral basic trajectory, with the basic spiral radius R = αθ; where θ is the polar angle and α is the proportionality coefficient; α = 0.1-0.5 μm / rad, used to achieve a laser irradiation fill factor of >95% and a laser uniform energy distribution with fluctuation of <5%.

[0014] Furthermore, to support closed-loop control throughout the entire processing, the following real-time feedback mechanism is implemented during the processing of the microholes: After every 5 layers of laser irradiation, a confocal microscopy system is used to detect the curvature error and interlayer misalignment of the micropores.

[0015] By adopting the above technical solution, the present invention can bring the following beneficial effects: This invention employs a method that first sets the defocus amount based on the retinal topography map, then substitutes it into the formula to calculate the refractive power of each micropore, and then determines the depth and diameter through iterative optimization. This method digitally quantifies the non-rotationally symmetric micropore array model, filling the gap in existing technologies that cannot process non-rotationally symmetric micropore arrays. This invention uses layer-by-layer scanning to process micropores, which can avoid the formation of modified zones or molten layers; This invention incorporates white light interferometry to avoid depth and tilt angle errors during the fabrication of micro-holes. This invention establishes a topological map and integrates it into the micro-hole processing process, laying the foundation for continuous processing of each micro-hole, secondary processing of specific micro-holes, and the creation of new micro-holes. During the micropore processing, the present invention also uses a confocal microscope to monitor the micropore curvature error and interlayer misalignment in real time, thereby realizing the closed-loop control of the automatic continuous processing of the micropore array of the present invention. This invention selects characteristic regions based on retinal topography and integrates data such as corneal asymmetry factors to establish a non-rotationally symmetric human eye optical model. Compared with existing reference models for defocused lenses, the model establishment method is more reasonable. Consequently, the defocused lenses prepared based on this invention have better corrective effects for patients. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the overall design and processing flow of a method for fabricating asymmetrically distributed surface microporous defocused lenses based on femtosecond lasers in a specific embodiment of the present invention. Figure 2 This is a logic diagram of the micropore processing technology of the present invention. Detailed Implementation

[0018] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0019] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0020] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0021] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The illustrations only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0022] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0023] In one embodiment of the present invention, a method for fabricating a surface microporous defocusing lens based on asymmetric distribution of femtosecond laser is provided, such as... Figure 1 , 2 As shown, it includes the following steps: S101: Extract multiple feature regions from the retinal topography of the eyeball, the sum of which covers the fovea centralis or the edge of the optic disc in the retina of the eyeball; S102: Integrate corneal asymmetric morphology factors, retinal feature region axial length and / or retinal feature region curvature data to construct a multi-dimensional bioparameter database; S103: Based on the information in the database, multiple optical zones are set on the lens, and a defocus amount is set for each optical zone to make the lens adapt to the correction defocus amount requirements and anisometropy defocus amount requirements of different areas of the eyeball. S104: Based on the calculated defocus amount of each optical zone, calculate the refractive power of each micropore in different regions, and then iteratively optimize to determine the depth and diameter of the micropore after obtaining the refractive power; S105: The depth and diameter of the micro-holes are converted into direct-write processing data for femtosecond laser processing, and each of the micro-holes is continuously processed based on the direct-write processing data.

[0024] In this embodiment, in order to improve the overall performance of the lens, the factors for setting the defocus amount of each zone include the corneal asymmetry morphology factor of the eyeball, the axial length of the retinal characteristic region, and the retinal curvature. The defocus amount of each partition is used to adapt to the corrective defocus amount requirements and anisometropic defocus amount requirements of different areas of the eyeball.

[0025] In the retinal topography map of this embodiment, the grid for dividing the feature regions is generally square or circular sector-shaped; each optical zone in this embodiment also adopts a square or circular sector-shaped grid. For ease of design, multiple grids can be included in one optical zone. The defocus amount of each optical zone in this embodiment is calculated considering the corneal asymmetry morphology factor, the axial length of the retinal feature region, and the retinal curvature.

[0026] In this embodiment, the depth and diameter of the micropore are calculated based on the following formula:

[0027] in: The refractive power of the micropore; For optical partition (i, j), the positive defocus amount is given. The refractive index of the lens material; The radius of curvature of the lens at a distance r from the optical center; This is the pore size diffraction correction factor for the micropores. , The theoretical focal length of the micropore. ; is the depth gradient coefficient of the micropore; The diameter of the micro-hole located at a radius r from the optical center of the lens; is the diameter gradient coefficient of the micropores.

[0028] In this embodiment, the defocus amount is first set in sections on the lens according to the retinal topography map, then the refractive power of each micropore is calculated by substituting into the above formula, and then the depth and diameter of the micropore are determined by iterative optimization.

[0029] This embodiment uses a mathematical model to directly map the positive defocus of the optical partition to the refractive power of the microaperture, and then further derives the depth and diameter of the microaperture. Several correction factors are introduced in the above formula to adapt to the asymmetric characteristics of the human eye.

[0030] In this embodiment, the micropores are processed by femtosecond laser layer-by-layer scanning, and the femtosecond laser processing data of the micropores is obtained based on the following formula:

[0031] in The material bulging efficiency coefficient (µm) of the lens 3 / µJ), E The energy of a single femtosecond laser pulse (µJ) The number of pulses that remain at a single point during focused spot processing. Normal scan spacing (µm) The scanning speed is denoted as (mm / s).

[0032] In this embodiment, the micro-hole depth and diameter calculated in S104 are used as input, and the laser parameters are derived by using a formula. The processing formula converts the micro-hole depth and diameter, among other specifications, into laser processing parameters, including single-pulse energy, pulse number, scanning interval, and speed. The formula in this embodiment takes material properties into account to eliminate processing errors.

[0033] In this embodiment, in order to achieve continuous processing of each optical zone on the lens, when processing each of the micro-holes, after each zone completes femtosecond direct-write processing, white light interferometer detection is performed, and the detection results of the white light interferometer are obtained: When the depth error of the microhole is >5%, adjust the Z-axis compensation amount when machining the microhole with laser pulse. When the tilt angle deviation of the micro-hole is >2°, adjust the number of circular scans when processing the micro-hole with laser pulse; Generate a topology map of each micropore, record the coordinates and historical processing parameters of each micropore, and support subsequent iterations.

[0034] When adding micropores in this embodiment: in the unprocessed area, micropores are added at a spacing ≥50μm according to the new refractive data; This embodiment extends the depth by etching the existing micropores, reducing the energy to 8-12 μJ and increasing the depth by 50-100 μm, corresponding to the change from h to h' in the figure. In this embodiment, when performing hole shape correction, femtosecond laser direct writing is used to correct the sidewall roughness (Ra<0.1μm).

[0035] In this embodiment, when secondary processing of micropores is required, the topology map is used as data support, and the laser scanning starting point is set on the edge of a polygon 10 μm inside the maximum diameter of the existing micropores in a plane 10 μm above the bottom layer; the secondary processing is used to enlarge the diameter of the existing micropores or deepen the depth of the existing micropores.

[0036] In this embodiment, in order to improve the adaptability to processing different materials, the wavelength range of the femtosecond laser includes: 1010-1070nm, 510-550nm, 330-350nm and 250-260nm; the single pulse energy of the femtosecond laser is 1-60μJ, the repetition frequency is 20Hz-1MHz and the average power is 1-30W.

[0037] In this embodiment, in order to achieve a non-centrosymmetric processing scanning trajectory, the path planning algorithm used to process each of the micro-holes is an Archimedean spiral basic trajectory, with the basic spiral radius R = αθ; where θ is the polar angle and α is the proportionality coefficient; α = 0.1-0.5 μm / rad, achieving a laser irradiation fill factor of >95% and a laser uniform energy distribution with fluctuation of <5%; at the same time, when performing femtosecond laser processing, this embodiment adopts a multi-focus parallel scanning method with 10-20 focal points for synchronous processing.

[0038] In this embodiment, to support closed-loop control throughout the entire processing, the following real-time feedback mechanism is implemented when processing the microholes: After every 5 layers of laser irradiation, the curvature error (<3%) and interlayer misalignment (±0.2μm in XY direction, ±0.1μm in Z direction) of the micropores were detected using a confocal microscopy system (axial resolution 0.1μm).

[0039] In this embodiment, the dynamic adjustment range of single-point defocus amount reaches ±3.00D (the traditional solution is ≤±0.50D), and it supports more than 1000 iterative correction processes.

[0040] This embodiment achieves an XY direction error of ±0.2μm and a Z direction error of ±0.1μm based on a micron-level multi-axis galvanometer displacement platform, and suppresses multi-layer superposition distortion by combining closed-loop feedback system control.

[0041] In this embodiment, the processing time for 50-layer stacking is ≤15min (the traditional single-layer processing takes 30min), and the efficiency is improved by 3-5 times through multi-focus parallel scanning (10-20 focus simultaneous processing).

[0042] The overall technical advantages of this embodiment are: Multi-parameter collaborative optimization: Achieving a dual breakthrough in material adaptability and processing precision through dynamic matching of wavelength, energy, and spacing; Intelligent path planning: The spiral path combined with high-precision three-dimensional femtosecond laser direct writing technology ensures the optical consistency of the high-density microlens array; Closed-loop manufacturing system: Based on white light interferometer detection, a closed loop of "processing-inspection-correction" is formed to overcome the irreversible defects of traditional processes.

[0043] This embodiment solves the core problems in traditional microlens processing, such as insufficient dynamic adjustment capability, poor interlayer consistency, and accumulation of interlayer misalignment, through the innovative integration of femtosecond laser direct writing technology, providing a full-cycle solution for personalized refractive correction.

[0044] The following explanation is based on the simplified 9-zone lens design. Figure 2As shown, the nine optical zones include a central circle (corresponding to the central area of ​​the eyeball) and eight annular sectors set outside the central circle. Together, the nine optical zones form a circular structure.

[0045] Geometric parameter formulas:

[0046] Pick , , , , The calculation results are shown in Table 1.

[0047] Table 1 Calculation results of micropore size

[0048] Since r is consistently set to 30mm in this example, it can be seen that under the same radius, the micropore depth and diameter are basically the same, while the radius of curvature is different. When r takes different values, the micropore depth and diameter will change under different radii, which is consistent with the design concept.

[0049] Based on the calculation results of the micropores above, perform the following steps: Equipment and material preparation: Provide resin or PC lens substrates, set up a femtosecond laser system (wavelength coverage of 1010-1070nm near-infrared, 510-550nm green light, 330-350nm ultraviolet, and 250-260nm deep ultraviolet bands), equipped with a Z-axis piezoelectric platform (10nm resolution), a white light interferometer (detection accuracy ±0.5μm), and a galvanometer scanning system; fix the lens on a five-axis worktable to ensure surface flatness error <0.1μm; initialize the parameter database, including sector division, laser energy, and scanning point spacing configuration.

[0050] Asymmetric partitioned scanning execution: The lens is divided into 9 optical zones according to specific needs; the high-density zone is set with a laser energy of 22-25 μJ and a scanning point spacing of 80 µm (density 120 points / cm²), and the low-density zone is set with a laser energy of 16-18 μJ and a point spacing of 120 μm (density 70 points / cm²); the Archimedean spiral trajectory is scanned layer by layer (basic spiral radius R=aθ, a=0.1-0.5 μm / rad, fill factor>95%). =1µm), ensuring uniform energy distribution (fluctuation <5%). Topography closed-loop detection and correction: After each sector is processed, a white light interferometer is triggered to detect the micro-hole structure: If the micro-hole depth error is >5% (e.g., the target depth is 200μm, but the measured depth is >210μm), the Z-axis compensation is adjusted to ±10μm; if the sidewall tilt angle deviation is >2° (e.g., the target depth is 75°, but the measured tilt angle is >77°), the number of ring scans is optimized (increased from 3 to 5); a micro-hole topology map is generated, and the coordinates, depth, tilt angle and historical processing parameters of each hole are recorded (stored in the database) to support subsequent iterative operations.

[0051] Iterative modification operation: Dynamic adjustment is performed based on new refractive data: When adding micropores, new pores are added in the unprocessed area (safe spacing ≥ 50 μm) according to the new parameters (dot spacing and energy are adapted to the target density); when the depth is extended, existing micropores are etched (laser energy is reduced to 8-12 μJ, and the depth is increased by 50-100 μm); when the hole shape is corrected, femtosecond laser direct writing (wavelength 515 nm, energy 1 μJ) is used to trim the sidewalls, and the roughness is controlled at Ra < 0.1 μm; after processing every 5 layers, the confocal microscopy system is started to detect curvature error (<3%) and interlayer misalignment (XY ± 0.2 μm, Z ± 0.1 μm), and the parameters of subsequent layers are adjusted in real time (pulse energy ± 10%, scanning spacing ± 5 nm).

[0052] Real-time feedback and efficiency optimization: Integrated half-wave plate-PBS energy controller and galvanometer displacement platform to achieve closed-loop control; multi-focus parallel scanning (10-20 focus synchronization) improves efficiency, 50-layer processing time ≤15min; after processing, verify the dynamic adjustment range of defocus amount ±3.00D (supports 1000 iterations), surface roughness Ra<0.1μm, light transmittance ≥97%, and complete lens output.

[0053] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for fabricating a defocused lens with asymmetrically distributed surface micropores based on femtosecond laser, characterized in that, include: Multiple optical zones are set on the lens. Based on the defocus amount of each optical zone, the refractive power of the micro-hole in each optical zone is calculated by region. After obtaining the refractive power, the depth and diameter of the micro-hole are determined by iterative optimization. Then, the depth and diameter of the micro-hole are converted into direct-write processing data for femtosecond laser processing. Based on the direct-write processing data, each micro-hole is continuously processed. The micropores are processed using a femtosecond laser layer-by-layer scanning method, and the femtosecond laser processing data for the micropores is obtained based on the following formula: In the formula, Let be the depth of the micro-hole on the lens at a radius r from the optical center. The material bulging efficiency coefficient of the lens. E For femtosecond laser single pulse energy, The number of dwell pulses per point processed by a femtosecond laser focused spot. The normal scanning distance of the lens during femtosecond laser processing. v The scanning speed of the femtosecond laser spot. is the maximum radius of the lens, and r is the distance between the processed micro-hole and the optical center of the lens; The optical partitioning method includes the following steps: S101: Extract multiple feature regions from the retinal topography of the eyeball, the sum of which covers the fovea centralis or the edge of the optic disc in the retina of the eyeball; S102: Integrate corneal asymmetric morphology factors, retinal feature region axial length, and retinal feature region curvature data to construct a multi-dimensional biological parameter database; S103: Based on the information in the database, multiple optical zones are set on the lens, and a defocus amount is set for each optical zone to make the lens adapt to the correction defocus amount requirements and anisometropia defocus amount requirements of different areas of the eyeball.

2. The method for fabricating asymmetrically distributed surface micropore defocusing lens based on femtosecond laser according to claim 1, characterized in that, The depth and diameter of the micropores are calculated based on the following formula: in: The refractive power of the micropore; For optical partition (i, j), the positive defocus amount is given. The refractive index of the lens material; The radius of curvature of the lens at a distance r from the optical center; This is the pore size diffraction correction factor for the micropores. , The theoretical focal length of the micropore. ; is the depth gradient coefficient of the micropore; The diameter of the micro-hole located at a radius r from the optical center of the lens; is the diameter gradient coefficient of the micropores.

3. The method for fabricating asymmetrically distributed surface micropore defocusing lens based on femtosecond laser according to claim 1, characterized in that, During the fabrication of each of the aforementioned micro-holes, after each partition has completed femtosecond direct-write fabrication, a white light interferometer is used for detection. The detection results from the white light interferometer are then obtained as follows: When the depth error of the microhole is >5%, adjust the Z-axis compensation amount when machining the microhole with laser pulse. When the tilt angle deviation of the micro-hole is >2°, adjust the number of circular scans when processing the micro-hole with laser pulse; Generate a topology map of each micropore.

4. The method for fabricating asymmetrically distributed surface micropore defocusing lens based on femtosecond laser according to claim 3, characterized in that, When performing secondary processing on the micropores on the lens, the topology map is used as data support, and the laser scanning starting point is set on the edge of a polygon 10 μm inside the maximum diameter of the micropore in a plane 10 μm above the bottom layer of the existing micropore; the secondary processing is used to enlarge the diameter of the existing micropore or deepen the depth of the existing micropore.

5. The method for fabricating a defocused lens with asymmetric surface micropores based on femtosecond laser according to claim 1, characterized in that, The wavelength range of the femtosecond laser includes: 1010-1070nm, 510-550nm, 330-350nm and 250-260nm; the single pulse energy of the femtosecond laser is 1-60μJ, the frequency is 20Hz-1MHz and the average power is 1-30W.

6. The method for fabricating a defocused lens with asymmetric surface micropores based on femtosecond laser according to claim 1, characterized in that, When processing the microholes with femtosecond laser, the laser scanning path used is the basic trajectory of the Archimedean spiral, and the radius of the basic spiral is R = αθ; where θ is the polar angle and α is the proportionality coefficient; α = 0.1-0.5 μm / rad, which is used to achieve a laser irradiation fill factor of >95% and a uniform laser energy distribution with fluctuation of <5%.

7. The method for fabricating asymmetrically distributed surface micropore defocusing lens based on femtosecond laser according to claim 1, characterized in that, The following real-time feedback mechanism is set up when processing the micropores: After every 5 layers of laser irradiation, a confocal microscopy system is used to detect the curvature error and interlayer misalignment of the micropores.

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