High-throughput super-resolution laser direct writing device and method based on superstructured surface

Abstract

The application discloses a high-flux super-resolution laser direct writing device and method based on a superstructure surface. The high-flux super-resolution laser direct writing device adopts a single superstructure surface to realize simultaneous shaping of excitation light and suppression light arrays through wavelength polarization multiplexing, replaces a complex independent shaping and beam combining optical path in a traditional scheme, greatly simplifies a system structure, and enables the generated excitation light and suppression light to completely propagate in a common path after passing through a DMD and to be shaped by a single superstructure surface, eliminates alignment errors and relative drift problems of two light beams, and guarantees stability of a super-resolution processing effect.

Description

Technical Field

[0001] This invention belongs to the field of optical technology, specifically relating to a high-throughput super-resolution laser direct writing device and method based on metasurfaces. Background Technology

[0002] Laser direct writing technology plays an increasingly crucial role in contemporary micro- and nano-fabrication, particularly excelling in integrated circuit manufacturing, optical microstructure devices, 3D smart sensors, and biophotonics applications. Advances in this technology directly drive the manufacturing capabilities of advanced chips and precision sensing devices.

[0003] Laser direct-write lithography has attracted much attention due to its high cost-effectiveness and user-friendly operating environment. However, traditional laser direct-write systems have two main technical bottlenecks: first, most systems use a single-source point-to-point serial scanning method, resulting in low processing efficiency and severely limited production capacity; second, due to the optical diffraction limit, conventional single-beam systems cannot achieve nanometer-level processing precision, failing to meet the ever-increasing demand for high-precision manufacturing.

[0004] In the field of optical microscopy, stimulated emission loss (STED) technology has successfully overcome the diffraction barrier, providing higher resolution imaging capabilities, meeting the observation needs of microstructures in materials science and biomedicine, and opening up a super-resolution path for laser direct writing. In a laser direct writing configuration, STED technology uses one excitation beam and the other is a vortex beam that controls the excitation. The latter, due to the presence of a sub-diffraction-limited dark area distribution in its focused field, can be used as a suppression or loss beam to indirectly optimize resolution.

[0005] Patent application CN112731776A discloses a dual-mask high-throughput, super-resolution laser direct writing method and apparatus. The main components include a polarization control module, a collimation and beam expansion system, an excitation beam array mask, a polarization beam splitter, a suppression light virtual mask formed by four-beam interference, a focusing high numerical aperture objective lens, and a three-dimensional controllable precision displacement stage. The spatial light modulator continuously loads different computational holograms in real time to achieve the switching of sub-beams in the excitation beam array, thereby realizing the direct writing of different patterns. The four beams interfere at certain angles to form an optical mask as a suppression light array, thus improving the direct writing resolution. This makes the direct writing effect of the system richer, and further improves the direct writing efficiency and resolution, effectively solving the problems of slow writing speed and low resolution in existing laser direct writing systems.

[0006] Patent application CN113189847A discloses a multi-channel parallel super-resolution direct-write lithography system based on a fiber optic mode-selective coupler. The system's laser direct-write process achieves photopolymerization of negative photoresist through the two-photon effect of the excitation light. A ring-shaped suppression beam is introduced to prevent photopolymerization of the photoresist in the edge region of the excitation light focal spot, enabling the minimum feature size of the direct-write lithography to break through the optical diffraction limit. Both the excitation beam and its corresponding ring-shaped suppression beam are generated by the same fiber optic mode-selective coupler, and the two beams naturally exhibit coaxial transmission characteristics when exiting the coupler. By multiplexing multiple fiber optic mode-selective couplers in the system, and coordinating the control of fiber optic switch arrays and other optical and mechanical components, it is expected to achieve large-scale parallel direct-write with over 10,000 beams, significantly improving the operating efficiency of the direct-write lithography system.

[0007] However, the systems disclosed in the aforementioned patent applications are quite complex, and the super-resolution effect needs to be further improved. Therefore, it is urgent to develop a multi-channel parallel direct writing strategy to meet the requirements of high-speed and high-resolution laser direct writing. Summary of the Invention

[0008] This invention provides a high-throughput super-resolution laser direct writing device based on metasurfaces. The super-resolution laser direct writing device has a relatively simple structure and achieves high throughput and super-resolution.

[0009] This invention provides a high-throughput, super-resolution laser direct writing device based on metasurfaces, comprising: An excitation beam unit is used to generate an excitation beam and sequentially perform horizontal polarization, dispersion compensation, chromatic dispersion compensation and beam expansion on the excitation beam. A suppression beam unit is used to generate a suppression beam and sequentially vertically polarize and expand the suppression beam. A beam-forming unit, comprising a polarizing beam splitter, a DMD, a 4f system, and a metasurface according to the direction of light propagation, wherein the polarizing beam splitter is used to combine the expanded suppression beam and the excitation beam to obtain a combined beam; the DMD is used to spatially modulate the incident combined beam based on a loaded binary pattern sequence to obtain a composite beam array containing the excitation beam and the suppression beam; the composite beam array is irradiated onto the metasurface through the 4f system, wherein the metasurface is a wavelength polarization multiplexing phase plate; the metasurface is used to superimpose a secondary phase on the excitation beam array and focus it into a Gaussian beam array, and superimpose a vortex phase on the suppression beam array and focus it into a hollow annular beam array, thereby forming a composite beam array; A direct-write unit is used to image the composite spot array onto the sample surface of the displacement stage to form a super-resolution parallel direct-write dot matrix.

[0010] Preferably, the method for determining the size of the metasurface includes: The metasurface consists of periodically arranged metaunits, and the length and width of each metaunit are independently designed according to the target phase distribution; Among them, the phases of the suppression beam array and the excitation beam array under their respective working wavelengths and polarizations satisfy the preset target phase distribution, while satisfying the set transmittance target. Using electromagnetic simulation method, under the condition of fixed height and period of meta-unit, the length and width parameters of each meta-unit are scanned to establish a Jones matrix database covering the complete phase space. The dimensions of the metasurface are obtained by retrieving and selecting the parameter combination of length and width of each metaunit that corresponds to the minimum deviation between the Jones matrix and the target phase distribution.

[0011] By searching the entire database, we find a structure that minimizes the total error and place it at a specific location on the metasurface, thereby making the phase distribution of the output light close to the target phase while meeting the manufacturing process limitations of the metasurface.

[0012] More preferably, for the excitation beam array, the phase at the metasurface is an array of multiple secondary phase periods arranged in a specific pattern, and the phase distribution provided by the metasurface in each secondary phase region of the corresponding array is... for: in, k 1 = 2π / λ1, where λ1 is the center wavelength of the excitation beam array. f Focal length r The radial distance from the sampling point to the center of the secondary phase is given. The periodic arrangement of the phases provided by this invention enables all incident excitation beam arrays to be focused into a regularly arranged Gaussian beam array.

[0013] More preferably, for the beam suppression array, the phase at the metasurface is an array of lens phases periodically arranged from multiple superimposed vortices. Only this array can form a hollow annular beam array. The phase distribution provided by the metasurface at the lens phase of each superimposed vortex in the corresponding array... for: in, l For topological load number, θ The azimuth angle of the sampling point relative to the lens phase center of the superimposed vortex. k 2 = 2π / λ², where λ² is the center wavelength of the suppression beam array. f Focal length rThis is the radial distance from the sampling point to the center of the lens phase of the superimposed vortex. The periodic arrangement of the phases provided by this invention enables all incident suppressed beam arrays to be focused into a regularly arranged hollow ring-shaped beam array.

[0014] Preferably, the metasurface includes a substrate and metaunits periodically arranged on the substrate, each metaunit being a rectangular nanopillar, the substrate material being fused silica, and the material of the rectangular nanopillars being selected from titanium dioxide (TiO2), silicon nitride (Si3N4), or single-crystal silicon, etc.

[0015] The rectangular nanopillars selected in this invention are made of a medium material with high refractive index and low absorption loss in the operating wavelength range.

[0016] More preferably, the height of the rectangular nanopillars is set between 500 nm and 1000 nm, and the period between the rectangular nanopillars is set between 320 nm and 500 nm. The specific values ​​of the above parameters are adapted and optimized based on the optical properties of the selected material and the manufacturing process requirements.

[0017] Preferably, the 4f system is composed of a fifth lens and a sixth lens. The DMD is located on the object-side focal plane of the 4f system composed of the fifth and sixth confocal lenses, and the metasurface is located on the image-side focal plane of the 4f system, thereby conjugating the pattern formed on the DMD to the metasurface and ensuring the accurate transmission of modulation information.

[0018] Preferably, the system further includes a computer equipped with a preset control synchronization algorithm. This algorithm calculates the binary pattern sequence of the DMD during the scanning process in real time based on preset graphic data and the scanning path, sends the binary pattern sequence to the DMD, and synchronously controls the displacement stage to move the sample. This invention utilizes the aforementioned control synchronization algorithm to achieve the linkage between the spatial amplitude modulation of the DMD and the movement of the displacement stage, enabling high-throughput, super-resolution continuous direct writing of the sample.

[0019] Preferably, the displacement stage is a high-precision displacement stage driven by piezoelectric or motor, which can accurately control the position of the sample in three-dimensional space.

[0020] Preferably, the DMD has high reflectivity in the visible light band and a maximum refresh rate of 23kHz to support high-speed parallel direct writing.

[0021] Preferably, the excitation beam unit includes a first laser, a first polarization control module, a dispersion compensation module, and a chromatic aberration compensation module according to the direction of light propagation. The first laser is used to generate an excitation beam, the first polarization control module is used to adjust the excitation beam to horizontal polarization, the dispersion compensation module is used to introduce negative dispersion into the excitation beam to achieve pre-compensation for beam broadening, and the chromatic aberration compensation module is used to generate pre-compensated chromatic aberration and expand the beam.

[0022] More preferably, the first polarization control module includes a first half-wave plate and a first polarizer according to the direction of light propagation. The half-wave plate is fixed on a rotatable optical frame, and the polarization direction of the incident laser can be continuously changed by rotating the half-wave plate around the optical axis. The polarizer is fixed on the optical frame and is used to purify the polarization state, ensuring that the transmitted laser is linearly polarized light with a high extinction ratio.

[0023] More preferably, the dispersion compensation module consists of a pair of parallel gratings and a roof prism. By adjusting the spacing of the pair of parallel gratings, negative dispersion is introduced into the polarized excitation beam to pre-compensate the dispersion introduced by the broadening of the femtosecond laser pulse, ensuring that the time width and spectral distribution of the laser pulse remain in the optimal state during the generation of the excitation beam array.

[0024] More preferably, the pair of parallel gratings are a first grating and a second grating. After the polarized excitation beam is diffracted by the first grating, different wavelength components are spatially separated. The separated beam is then diffracted by the second grating and reflected back by the roof prism. The returned beam passes through the second grating and the first grating again, and is re-beamed before being emitted, thereby introducing negative dispersion and achieving pre-compensation for femtosecond laser pulse broadening that may be introduced by subsequent elements.

[0025] More preferably, the piezoresistive compensation module includes a transmissive blazed grating and a pair of confocal lenses in the direction of light propagation. The transmissive blazed grating is used to generate pre-compensated piezoresistive dispersion that matches the inherent piezoresistive dispersion of the DMD. The pair of confocal lenses are used to enlarge the beam spot radius to facilitate beam expansion, which is beneficial to cover the entire effective area of ​​the DMD and make full use of its modulation performance.

[0026] Preferably, the suppression beam unit includes a second laser, a second polarization control module, and a beam expander module according to the direction of light propagation. The second laser generates a suppression beam, the second polarization control module is used to adjust the suppression beam to vertical polarization, and the beam expander module is used to expand the vertically polarized suppression beam.

[0027] More preferably, the second polarization control module includes a second half-wave plate and a second polarizer according to the direction of light propagation. The second half-wave plate is fixed on a rotatable optical frame, and the polarization direction of the incident laser can be continuously changed by rotating the half-wave plate around the optical axis. The second polarizer is fixed on the optical frame to purify the polarization state, ensuring that the transmitted laser is linearly polarized light with a high extinction ratio.

[0028] More preferably, the beam expanding module is a beam expanding system composed of a third lens and a fourth lens with a confocal surface, which expands the beam to match the effective target surface size of the DMD.

[0029] Preferably, the direct writing unit includes a seventh lens, an objective lens, and a displacement stage according to the direction of light propagation. The composite light spot array enters a 4f system composed of a confocal seventh lens and an objective lens, and is imaged by the objective lens onto the sample surface of the displacement stage to form a super-resolution parallel direct writing array.

[0030] This invention also provides a high-throughput super-resolution laser direct writing method based on metasurfaces, employing the aforementioned high-throughput super-resolution laser direct writing device based on metasurfaces, comprising: An excitation beam is generated by the excitation light unit, and the excitation beam is sequentially subjected to horizontal polarization, dispersion compensation, chromatic dispersion compensation and beam expansion. The suppression beam is generated by the suppression light unit, and the suppression beam is then vertically polarized and expanded in sequence. The beam-forming unit combines the expanded suppression beam and the excitation beam to obtain a beam-combined beam. Based on the loaded binary pattern sequence, the incident beam-combined beam is spatially amplitude modulated to obtain a composite beam array containing the excitation beam and the suppression beam. The composite beam array is then irradiated onto a metasurface, which is used to superimpose a secondary phase on the excitation beam array to form a Gaussian beam array and superimpose a vortex phase on the suppression beam array to form a hollow annular beam array, thereby forming a composite beam array. The composite spot array is imaged onto the sample surface of the displacement stage using a direct-write unit, forming a super-resolution parallel direct-write dot matrix.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses a single metasurface to achieve simultaneous shaping of excitation and suppression light arrays through wavelength polarization multiplexing, replacing the complex independent shaping and beam combining optical paths in the traditional scheme, which greatly simplifies the system structure.

[0032] (2) In this invention, the excitation light and the suppression light propagate in the same path after passing through the DMD and are shaped by a single metasurface. Compared with the prior art, which requires adjusting the phase of each light path to obtain different phases and then combining the two beams, and then aligning the phases of the two beams to align the center of the hollow spot and the center of the Gaussian beam, the light generated by the single metasurface provided by this invention is combined and aligned, and no further beam combining is required. This eliminates the alignment error and relative drift problem of the two beams and ensures the stability of the super-resolution processing effect.

[0033] (3) This invention utilizes the high-speed refresh characteristics of DMD to generate a large-scale beam array, realizing parallel processing. Compared with traditional single-point scanning technology, the direct writing efficiency can be greatly improved, realizing high-throughput laser direct writing. At the same time, by controlling the DMD to load dynamic pattern sequences through computer control, each processing point in the parallel array can be independently controlled to "on / off". Combined with the synchronous movement of the three-dimensional displacement stage, it is possible to flexibly and efficiently manufacture any complex graphics. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the optical path of the laser direct writing device of the present invention.

[0035] Among them: 1-First laser, 2-First half-wave plate, 3-First polarizer, 4-First total reflection mirror, 5-First grating, 6-Second grating, 7-Roof prism, 8-Second total reflection mirror, 9-Third grating, 10-First lens, 11-Second lens, 12-Second laser, 13-Second half-wave plate, 14-Second polarizer, 15-Third lens, 16-Fourth lens, 17-Third total reflection mirror, 18-Polarizing beam splitter, 19-Fourth total reflection mirror, 20-DMD, 21-Fifth lens, 22-Sixth lens, 23-Metasurface, 24-Seventh lens, 25-Objective lens, 26-Three-dimensional adjustable precision displacement stage, 27-Control computer.

[0036] Figure 2 The intensity distribution of the excitation beam array.

[0037] Figure 3 The intensity distribution of the beam array is shown in the diagram.

[0038] Figure 4 This is a schematic diagram of the metasurface unit structure of the present invention.

[0039] Figure 5 This is a schematic diagram of the metasurface structure of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should all be covered within the protection scope of this invention.

[0041] A specific embodiment of the present invention provides a high-throughput super-resolution laser direct writing device based on metasurfaces, such as... Figure 1 As shown, the device includes an excitation light unit, a suppression light unit, a light spot forming unit, and a direct writing unit.

[0042] The excitation light unit provided in the specific embodiment of the present invention includes a first laser 1, a first polarization control module, a dispersion compensation module and a chromatic aberration compensation module according to the direction of light propagation. The first polarization control module includes a first half-wave plate 2 and a first polarizer 3. The dispersion compensation module includes a first grating 5, a second grating 6 and a roof prism 7. The chromatic aberration compensation module includes a third grating 9, a first lens 10 and a second lens 11. The excitation light unit also includes a first total reflection mirror 4 and a second total reflection mirror 8.

[0043] In one embodiment, the first laser 1 is a femtosecond laser, outputting excitation light with a center wavelength of 780 nm. This excitation light is first adjusted to horizontal polarization by a polarization control unit composed of a first half-wave plate 2 and a first polarizer 3. Subsequently, this horizontally polarized light is reflected by a first total reflection mirror 4 and enters a dispersion compensation module composed of a first grating 5, a second grating 6, and a roof prism 7. In this module, the excitation light is diffracted by the first grating 5, and different wavelength components are spatially separated. The separated beam is then diffracted by the second grating 6 and reflected back by the roof prism 7. The returned beam passes through the second grating 6 and the first grating 5 again, is re-combined, and then emitted, thereby introducing negative dispersion to pre-compensate for femtosecond laser pulse broadening that may be introduced by subsequent components. The amount of dispersion compensation can be adjusted by changing the grating pair distance. The compensated beam is reflected by a second total reflection mirror 8 and enters a dispersion compensation module composed of a third grating 9, a first lens 10, and a second lens 11. This module pre-compensates for the angular dispersion that the DMD20 may introduce. At the same time, the first lens 10 and the second lens 11 of the confocal surface constitute a beam expanding system to expand the beam so that its spot completely covers the effective target surface of the DMD20.

[0044] The suppression beam unit provided in the specific embodiment of the present invention includes a second laser 12, a second polarization control module and a beam expansion module according to the direction of light propagation. The second laser 12 generates a suppression beam, the second polarization control module is used to adjust the suppression beam to vertical polarization, and the beam expansion module is used to expand the vertically polarized suppression beam.

[0045] The second polarization control module provided in this embodiment includes a second half-wave plate 13 and a second polarizer 14. The beam expansion module expands the beam of the beam expansion system composed of a third lens 15 and a fourth lens 16 with a confocal surface to match the effective target surface size of the DMD.

[0046] In one embodiment, the second laser 12 is a continuous laser that outputs a laser beam with a center wavelength of 532 nm, which is a suppressed beam. This suppressed beam is first adjusted to vertical polarization by a polarization control unit composed of a second half-wave plate 13 and a second polarizer 14. Subsequently, the suppressed beam is expanded by a beam-expanding system composed of a third lens 15 and a fourth lens 16 with confocal surfaces to match the effective target size of the DMD 20. The expanded suppressed beam is then reflected by a third total reflection mirror 17.

[0047] The light spot forming unit provided in a specific embodiment of the present invention includes a polarizing beam splitter 18, a DMD 20, a 4f system, and a metasurface 23 according to the direction of light propagation. The 4f system includes a fifth lens 21 and a sixth lens 22. The light spot forming unit also includes a third total reflection mirror 17 and a fourth total reflection mirror 19. In one embodiment, the horizontally polarized excitation beam emitted from the angular dispersion compensation module is transmitted through the polarizing beam splitter 18, while the vertically polarized suppression beam reflected from the third total reflection mirror 17 is reflected by the polarizing beam splitter 18, thereby combining the two beams into one beam and propagating along the same optical path. After being reflected by the fourth total reflection mirror 19, the combined beam is incident on the effective target surface of the DMD 20 at a certain incident angle. In one embodiment, the incident angle is 24°. The DMD 20 acts as a binary spatial light modulator. A preset binary image sequence is loaded by the control computer 27 to perform spatial amplitude modulation on the incident combined beam, forming a composite beam array containing excitation and suppression beams.

[0048] In a specific embodiment of the present invention, the composite beam array exiting the DMD 20 enters a 4f system composed of a fifth lens 21 and a sixth lens 22. The DMD 20 is located on the front focal plane of the fifth lens 21, and the metasurface 23 is located on the rear focal plane of the sixth lens 22, thereby imaging the pattern formed on the DMD 20 onto the metasurface 23. This metasurface 23 is a wavelength polarization multiplexed phase plate; when a horizontally polarized excitation beam array is incident, it superimposes a secondary phase onto it, focusing it as shown in the image. Figure 2 The Gaussian beam array shown; when the vertically polarized suppressed beam array is incident, a vortex phase is superimposed on it, so that it is focused as shown. Figure 3 The hollow ring-shaped light spot array shown.

[0049] Specific embodiments of the present invention provide a method for determining the dimensions of the metasurface, including: The metasurface comprises periodically arranged metaunits, each of which has its length L and width W independently designed according to a target phase distribution, thus obtaining... Figure 5 The metasurface array shown; Among them, the phases of the suppression beam array and the excitation beam array under their respective working wavelengths and polarizations satisfy the preset target phase distribution, while also satisfying the set transmittance target. Using electromagnetic simulation methods, under the condition of fixed height and period of the meta-unit, the length and width parameters of each meta-unit are traversed and scanned to establish a Jones matrix database covering the complete phase space.

[0050] The dimensions of the metasurface are obtained by retrieving and selecting the parameter combination of length and width of each metaunit that corresponds to the minimum optical deviation between the Jones matrix and the target phase distribution.

[0051] In a specific embodiment of the present invention, the phase at the metasurface is an array of multiple quadratic phases arranged periodically. This array is necessary to form a Gaussian spot array. The multiple quadratic phase lenses are periodically arranged, and the phase distribution provided by the metasurface in each quadratic phase region of the corresponding array... for: in, k 1 = 2π / λ1, where λ1 is the wavelength of the excitation beam array. f Focal length r The radial distance from the sampling point to the center of the secondary phase is given. The periodic arrangement of the phases provided by the present invention enables all incident excitation beam arrays to be focused into a regularly arranged Gaussian beam array. In one embodiment, the center wavelength of the excitation beam array is 780 nm.

[0052] This invention specifically addresses beam suppression arrays. The phase at the metasurface is an array of lenses with periodically arranged superimposed vortices. Only this array can form a hollow annular beam array. The phase distribution provided by the metasurface in the lens phase region of each superimposed vortex in the corresponding array... for: Where l is the topological charge number, and θ is the azimuth angle of the sampling point relative to the lens phase center of the superimposed vortex. k 2 = 2π / λ², where λ² is the wavelength of the suppression beam array. f Focal length r This is the radial distance from the sampling point to the center of the lens phase of the superimposed vortex. The periodic arrangement of the phases provided by the present invention enables all incident suppression beam arrays to be focused into a regularly arranged hollow ring-shaped beam array. In one embodiment, the center wavelength of the suppression beam array is 532 nm.

[0053] like Figure 4 As shown, the metasurface provided in a specific embodiment of the present invention includes a substrate and metasurface units periodically arranged on the substrate. Period is the period size of the unit structure. Each metasurface unit is a rectangular nanopillar. The substrate material is fused silica, and the material of the rectangular nanopillars is selected from titanium dioxide (TiO2), silicon nitride (Si3N4), or single crystal silicon, etc.

[0054] The rectangular nanopillars selected in this invention are made of a medium material with high refractive index and low absorption loss in the operating wavelength range.

[0055] In a specific embodiment of the present invention, the height H of the rectangular nanopillars is set between 500 nm and 1000 nm, and the period between the rectangular nanopillars is set between 320 nm and 500 nm. The specific values ​​of the above parameters are adapted and optimized based on the optical properties of the selected material and the manufacturing process requirements.

[0056] The direct writing unit provided in the specific embodiment of the present invention includes a seventh lens 24, an objective lens 25 and a displacement stage 26 according to the direction of light propagation. The composite light spot array enters the 4f system composed of the seventh lens and the objective lens with a confocal surface, and is imaged by the objective lens onto the sample surface of the displacement stage to form a super-resolution parallel direct writing array.

[0057] Specifically, the composite spot array modulated by the metasurface 23 enters the 4f system composed of the seventh lens 24 with a confocal surface and the objective lens 25. Finally, the objective lens 25 images the sample surface placed on the three-dimensional adjustable precision displacement stage 26, forming a super-resolution parallel direct-write dot array composed of a Gaussian spot array and a hollow annular spot array. The focused spot array generated by the metasurface 23 is located at the front focal plane of the seventh lens 24, and the direct-write position is located at the rear focal plane of the objective lens 25.

[0058] The high-throughput, super-resolution laser direct writing device based on metasurfaces provided in this specific embodiment of the invention also includes a computer 27, which has a preset control synchronization algorithm. This algorithm calculates and generates a binary pattern sequence of the DMD 20 during the scanning process in real time based on preset graphic data and scanning path, and synchronously controls the three-dimensional adjustable precision displacement stage 26 to move the sample, thereby achieving high-throughput, super-resolution continuous direct writing of the sample.

[0059] This invention also provides a high-throughput super-resolution laser direct writing method based on metasurfaces, employing the aforementioned high-throughput super-resolution laser direct writing device based on metasurfaces, comprising: An excitation beam is generated by the excitation light unit, and the excitation beam is sequentially subjected to horizontal polarization, dispersion compensation, chromatic dispersion compensation and beam expansion. The suppression beam is generated by the suppression light unit, and the suppression beam is then vertically polarized and expanded in sequence. The beam-forming unit combines the expanded suppression beam and the excitation beam to obtain a combined beam. Based on the loaded binary pattern sequence, the incident combined beam is spatially amplitude modulated to obtain a composite beam array containing the excitation beam and the suppression beam. The composite beam array is then irradiated onto a metasurface, which is used to superimpose a secondary phase on the excitation beam array to form a Gaussian beam array and superimpose a vortex phase on the suppression beam array to form a hollow annular beam array, thereby forming a composite beam array. The composite spot array is imaged onto the sample surface of the displacement stage using a direct-write unit, forming a super-resolution parallel direct-write dot matrix.

[0060] The present invention provides a method for generating a suppressed beam array: after a continuous laser beam passes through a polarization control module and a beam expander, it is reflected by a polarization beam splitter and combined with the excitation beam, and then incident on a DMD for spatial amplitude modulation to form the desired suppressed beam array.

[0061] The present invention provides a method for generating an excitation beam array: after a femtosecond laser beam passes through a polarization control module, a dispersion compensation module, and a chromatic dispersion compensation module, it is transmitted through a polarization beam splitter and combined with the suppression beam, and then incident on a DMD for spatial amplitude modulation to form an excitation beam array that meets the array distribution requirements.

[0062] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-throughput, super-resolution laser direct-writing device based on metasurfaces, characterized in that, include: An excitation beam unit is used to generate an excitation beam and sequentially perform horizontal polarization, dispersion compensation, chromatic dispersion compensation and beam expansion on the excitation beam. A suppression beam unit is used to generate a suppression beam and sequentially vertically polarize and expand the suppression beam. A beam-forming unit, comprising a polarizing beam splitter, a DMD, a 4f system, and a metasurface according to the direction of light propagation, wherein the polarizing beam splitter is used to combine the expanded suppression beam and the excitation beam to obtain a combined beam; the DMD is used to spatially modulate the incident combined beam based on a loaded binary pattern sequence to obtain a composite beam array containing the excitation beam and the suppression beam; the composite beam array is irradiated onto the metasurface through the 4f system, wherein the metasurface is a wavelength polarization multiplexing phase plate; the metasurface is used to superimpose a secondary phase on the excitation beam array and focus it into a Gaussian beam array, and superimpose a vortex phase on the suppression beam array and focus it into a hollow annular beam array, thereby forming a composite beam array; A direct-write unit is used to image the composite spot array onto the sample surface of the displacement stage to form a super-resolution parallel direct-write dot matrix. For the excitation beam array, the phase at the metasurface is an array of multiple secondary phase periods arranged in a specific pattern. The phase distribution provided by the metasurface in each secondary phase region of the corresponding array... for: ,in, k 1 = 2π / λ1, where λ1 is the center wavelength of the excitation beam array. f Focal length r The radial distance from the sampling point to the center of the secondary phase; For the beam suppression array, the phase at the metasurface is an array of lens phases periodically arranged from multiple superimposed vortices. The phase distribution provided by the metasurface in the lens phase region of each superimposed vortex in the corresponding array is... for: ,in, l For topological load number, θ The azimuth angle of the sampling point relative to the lens phase center of the superimposed vortex. k 2 = 2π / λ², where λ² is the center wavelength of the suppression beam array. f Focal length r The radial distance from the sampling point to the lens phase center of the superimposed vortex.

2. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 1, characterized in that, The method for determining the dimensions of the metasurface includes: The metasurface consists of periodically arranged metaunits, and the length and width of each metaunit are independently designed according to the target phase distribution; Among them, to ensure that the phase distribution of the suppression beam array and the excitation beam array under their respective working wavelengths and polarizations meets the preset target phase distribution, and at the same time meets the set transmittance target, the electromagnetic simulation method is used to scan the length and width parameters of each meta-unit under the condition of fixed height and period, and to establish a Jones matrix database covering the complete phase space. The dimensions of the metasurface are obtained by retrieving and selecting the parameter combination of length and width of each metaunit that corresponds to the minimum deviation between the Jones matrix and the target phase distribution.

3. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 1, characterized in that, The metasurface includes a substrate and metaunits periodically arranged on the substrate. Each metaunit is a rectangular nanopillar. The substrate is made of fused silica, and the rectangular nanopillars are made of titanium dioxide, silicon nitride, or single-crystal silicon.

4. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 1, characterized in that, The excitation beam unit includes a first laser, a first polarization control module, a dispersion compensation module, and a chromatic dispersion compensation module according to the direction of light propagation. The first laser is used to generate an excitation beam, the first polarization control module is used to adjust the excitation beam to horizontal polarization, the dispersion compensation module is used to introduce negative dispersion into the excitation beam to achieve pre-compensation for beam broadening, and the chromatic dispersion compensation module is used to generate pre-compensated chromatic dispersion and expand the beam.

5. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 4, characterized in that, The dispersion compensation module consists of a pair of parallel gratings and a roof prism. By adjusting the spacing of the pair of parallel gratings, negative dispersion is introduced into the polarized excitation beam to pre-compensate the dispersion introduced by the broadening of the femtosecond laser pulse.

6. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 4, characterized in that, The spectral dispersion compensation module includes a transmissive blazed grating and a pair of confocal lenses in the direction of light propagation. The transmissive blazed grating is used to generate pre-compensated spectral dispersion that matches the inherent spectral dispersion of the DMD, and the pair of confocal lenses are used to expand the beam spot radius to facilitate beam expansion.

7. The high-throughput super-resolution laser direct writing device based on metasurfaces according to claim 1, characterized in that, The suppression beam unit includes a second laser, a second polarization control module, and a beam expander module according to the direction of light propagation. The second laser generates a suppression beam, the second polarization control module is used to adjust the suppression beam to vertical polarization, and the beam expander module is used to expand the vertically polarized suppression beam.

8. A high-throughput super-resolution laser direct writing method based on metasurfaces, employing the high-throughput super-resolution laser direct writing apparatus based on metasurfaces as described in any one of claims 1-7, characterized in that, include: An excitation beam is generated by the excitation light unit, and the excitation beam is sequentially subjected to horizontal polarization, dispersion compensation, chromatic dispersion compensation and beam expansion. The suppression beam is generated by the suppression light unit, and the suppression beam is then vertically polarized and expanded in sequence. The beam-forming unit combines the expanded suppression beam and the excitation beam to obtain a beam-combined beam. Based on the loaded binary pattern sequence, the incident beam-combined beam is spatially amplitude modulated to obtain a composite beam array containing the excitation beam and the suppression beam. The composite beam array is then irradiated onto a metasurface, which is used to superimpose a secondary phase on the excitation beam array to form a Gaussian beam array and superimpose a vortex phase on the suppression beam array to form a hollow annular beam array, thereby forming a composite beam array. The composite spot array is imaged onto the sample surface of the displacement stage using a direct-write unit, forming a super-resolution parallel direct-write dot matrix.

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