A sheet light-gated multi-focal dynamic addressing three-dimensional micro-nano machining system and method

Abstract

This invention discloses a sheet-gated multi-focal dynamic addressing three-dimensional micro / nano fabrication system, comprising: a first optical path module, a second optical path module, and a sample processing module; in the first optical path module, a first continuous laser beam emitted by a first laser forms multiple exposure focal points via a digital micromirror device, a Fourier transform lens, a spatial filter aperture, and a beam-shrinking conjugate imaging component arranged sequentially; in the second optical path module, a second continuous laser beam emitted by a second laser of a different wavelength from the first continuous laser beam is incident on a sheet-gated shaping component to form a sheet-like gated light field; the multiple exposure focal points generated by the first optical path module and the sheet-like gated light field generated by the second optical path module are respectively incident on the sample surface within a two-step absorbing photoresist supported on a substrate in the sample processing module; the digital micromirror device and the three-dimensional motion submodule work together to achieve the overlapping and aggregation of the sheet-like gated light field and the multiple exposure focal points on the sample surface and their distribution according to a preset three-dimensional micro / nano structure.

Description

Technical Field

[0001] This invention belongs to the field of optical technology, specifically relating to a sheet-gated multifocal dynamic addressing three-dimensional micro / nano fabrication system and method. Background Technology

[0002] Laser micro / nano fabrication technology enables the fabrication of two-dimensional or three-dimensional micro / nano structures in photoresists, photosensitive resins, and other photoresponsive materials, with significant applications in micro / nano optics, microfluidic chips, three-dimensional mechanical metamaterials, biological scaffolds, and integrated photonic devices. Traditional high-resolution three-dimensional micro / nano fabrication typically employs a single-focus two-photon polymerization direct-write method. However, two-photon polymerization usually relies on femtosecond pulsed lasers and their associated dispersion management, beam transmission, and power control systems, resulting in high equipment costs and system complexity. Furthermore, single-focus two-photon polymerization requires point-by-point, line-by-line, and layer-by-layer scanning, leading to low overall processing efficiency and making it difficult to meet the demands of large-area micro / nano structures, arrayed micro / nano optics, and high-throughput three-dimensional manufacturing.

[0003] Chinese patent application CN112596349A discloses a two-photon parallel direct-writing device and method based on multi-point array generation and independent control. The device mainly includes three core components: a digital micromirror array (DMD), a spatial light modulator (SLM), and a microlens array (MLA). The DMD divides the effective pixel area into N×N units, with each unit corresponding to a light spot. The m×m micromirrors in each unit of the DMD are independently switched on and off to achieve independent control of the intensity and uniformity of the light spot in each unit. The SLM divides the effective pixel area into N×N units and corresponds one-to-one with the incident light spot in each unit, and performs phase control independently. The MLA is used to generate a focal array, and the number of microlenses N×N determines the number of points. This point array is then imaged onto the focal plane of the objective lens by a convex lens and an objective lens for processing.

[0004] In this type of multifocal parallel direct writing method based on microlens arrays, the axial light field distribution of each focal point is affected not only by the objective lens depth of focus, entrance pupil filling state, focal light intensity distribution, and photoresist aggregation threshold, but also by the microlens array aperture, focal length, aberration, array uniformity, and crosstalk between sub-beams. When the microlens array causes insufficient effective numerical aperture of sub-beams, inconsistent axial focal positions, or enhanced side lobes, the axial aggregation region may be further elongated. In thick photoresist layers, multilayer structures, or low nonlinear lithography systems, problems such as defocus exposure, axial trailing, and aggregation in non-target areas are still prone to occur.

[0005] Chinese patent application CN114779591A discloses a super-resolution lithography method based on a two-color, two-step absorption effect. This method utilizes the spectral absorption characteristics of the ground and triplet states of a benzoyl photoinitiator. It employs two laser beams, one with wavelengths matching the material's ground-state absorption range and the other with wavelengths matching the material's triplet absorption range, acting simultaneously on the material. By controlling the energy of both beams, a two-color, two-step absorption effect is achieved. Furthermore, by controlling their relative displacement, a writing linewidth less than the diffraction limit is obtained. This invention primarily achieves localized focusing control through two focused beams or their relative displacement, but it has not yet effectively combined the dynamic holographic addressing capability, multi-focus parallel exposure capability, and axial gating capability of a sheet-like optical field characteristic of digital micromirror devices. Summary of the Invention

[0006] The purpose of this invention is to provide a sheet-gated multi-focus dynamic addressing three-dimensional micro-nano fabrication system. This system can reduce defocus exposure, axial trailing, and non-target area aggregation, and realize dynamic addressing and parallel exposure of multiple exposure focuses to improve the fabrication efficiency of three-dimensional micro-nano structures.

[0007] A sheet-gated, multi-focal, dynamically addressed 3D micro / nano fabrication system includes: The first optical path module includes a first laser, a digital micromirror device, a Fourier transform lens, a spatial filter aperture, and a beam-shrinking conjugate imaging component arranged sequentially. The first continuous laser beam emitted by the first laser is incident on the digital micromirror device for binary amplitude holographic modulation. The modulated first continuous laser beam is subjected to Fourier transform by the Fourier transform lens and then the spatial filter aperture selects a target multifocal array. The target multifocal array is then shrunken and conjugated by the beam-shrinking conjugate imaging component to form multiple exposure focal points. The second optical path module includes a second laser and a sheet light shaping component arranged in sequence. The second continuous laser beam emitted by the second laser is incident on the sheet light shaping component to form a sheet-shaped gated optical field. The sample processing module includes a substrate and a three-dimensional motion submodule. The substrate carries a two-step absorption photoresist. Multiple exposure focal points generated by the first optical path module and a sheet-like gated light field generated by the second optical path module are respectively incident on the sample surface within the two-step absorption photoresist. The wavelengths of the first continuous laser beam and the second continuous laser beam correspond to the two absorption wavelengths of the two-step absorption photoresist. The digital micromirror device and the three-dimensional motion submodule work together to achieve the overlapping and aggregation of the sheet-like gated light field and multiple exposure focal points on the sample surface and their distribution according to a preset three-dimensional micro / nano structure.

[0008] Furthermore, a first beam expander is provided between the first laser and the digital micromirror device. The first beam expander includes two cemented doublet achromatic lenses. The first continuous laser beam emitted by the first laser is expanded by the first beam expander to cover the entire working target surface of the digital micromirror device. A second beam expander is provided between the second laser and the sheet light shaping assembly. The second beam expander includes two cemented doublet achromatic lenses. The second continuous laser beam emitted by the second laser is expanded by the second beam expander to meet the beam size requirements of the second objective lens.

[0009] Furthermore, the beam-shrinking conjugate imaging assembly includes a relay lens and a first objective lens, used to shrink and conjugate the target multifocal array to the sample surface within the two-step absorbing photoresist, forming multiple exposure focal points.

[0010] Furthermore, the first optical path module also includes an illumination observation optical path submodule, which is disposed between the spatial filter aperture and the beam-conjugate imaging component. The illumination observation optical path submodule includes a beam splitter, a non-polarizing beam splitter prism, a camera, a lens, and a light-emitting diode. The light-emitting diode emits illumination light, which is split by the non-polarizing beam splitter prism through the lens. One of the split illumination beams is incident on the sample surface within the two-step absorption photoresist in the sample processing module for illumination via the beam splitter and the beam-conjugate imaging component. The reflected light, scattered light, or fluorescence signal on the sample surface is transmitted through the beam-conjugate imaging component and the beam splitter, and then through the non-polarizing beam splitter prism to the camera for signal acquisition, used to observe the exposed area, the polymerization area, or the processed three-dimensional micro / nano structure in the two-step absorption photoresist.

[0011] Furthermore, the second optical path module also includes a second objective lens, used to introduce the sheet-like gated light field formed by the sheet light shaping component into the sample surface within the two-step absorption photoresist.

[0012] Preferably, the optical axis of the first objective lens intersects the optical axis of the second objective lens, and the optical axis direction of the first objective lens intersects the thickness direction of the sheet-like gated light field, so as to define the axial region in which the polymerization reaction occurs within the two-step absorption photoresist.

[0013] Furthermore, the sheet light shaping component is one of a cylindrical lens, a Powell lens, a cylindrical lens group, a scanning beam shaping component, a Bessel beam generating component, or a spatial light modulation component, used to form a sheet-like gated light field.

[0014] Furthermore, the sample processing module also includes a sample pool for containing two-step absorption photoresist.

[0015] Furthermore, the three-dimensional motion submodule includes one of a three-dimensional moving platform, a piezoelectric moving platform, and an inertial piezoelectric platform, used to adjust the substrate to achieve micron- or nanometer-level displacement.

[0016] Furthermore, the three-dimensional micro / nano structure includes one of the following: microlens, microlens array, diffractive optical element, grayscale phase device, multilayer micro / nano optical device, microfluidic structure, three-dimensional mechanical metamaterial, or supported metasurface.

[0017] This invention also provides a sheet-gated multi-focus dynamic addressing three-dimensional micro / nano fabrication method. The multi-focus dynamic addressing three-dimensional micro / nano fabrication method using the above-mentioned multi-focus dynamic addressing three-dimensional micro / nano fabrication system includes: S1. Generate a binary amplitude hologram arranged in time sequence based on the three-dimensional micro-nano structure, place the two-step absorption photoresist on the substrate, and simultaneously start the first laser and the second laser to emit the first continuous light laser beam and the second continuous light laser beam corresponding to the two-step absorption wavelength of the two-step absorption photoresist, respectively. S2. The first continuous laser beam is incident on the digital micromirror device and subjected to binary amplitude holographic modulation based on the binary amplitude hologram. The modulated first continuous laser beam is incident on the Fourier transform lens for Fourier transform, and then the target multifocal array is selected by the spatial filter aperture. The target multifocal array is reduced and conjugated by the beam-shrinking conjugate imaging component to form multiple exposure focal points. The second continuous laser beam is incident on the sheet light shaping component to form a sheet-like gated light field. S3. The multiple exposure focal points and the sheet-like gated light field are respectively incident on the sample surface in the dual-step absorption photoresist. The digital micromirror device and the three-dimensional motion submodule work together to make the sheet-like gated light field and the multiple exposure focal points overlap on the sample surface according to the binary amplitude hologram, and the polymerization reaction only occurs in the overlapping area. S4. The digital micromirror device performs binary amplitude holographic modulation on the first continuous laser beam by switching binary amplitude holograms in a time sequence, and dynamically adjusts the substrate based on the three-dimensional motion submodule to complete the processing of the three-dimensional micro-nano structure one by one.

[0018] Furthermore, the first continuous laser beam and the second continuous laser beam have different wavelengths. The two wavelengths are respectively matched to the two-step absorption response process of the two-step absorption photoresist, so that the polymerization efficiency of the two-step absorption photoresist when the first continuous laser beam and the second continuous laser beam of different wavelengths work together is higher than the polymerization efficiency when either continuous laser beam works alone. Furthermore, the sheet-like gated light field formed by the second continuous laser beam is used to define the axial region within the two-step absorption photoresist where polymerization reactions can occur, thereby reducing the probability of defocusing exposure, axial trailing, and polymerization reactions occurring in non-target areas.

[0019] Furthermore, the three-dimensional micro / nano structure slice is divided into multiple two-dimensional processing layers, and each two-dimensional processing layer is discretized into multiple target exposure points. Based on the position of the target exposure points, the corresponding binary amplitude hologram is calculated to form a binary amplitude hologram arranged in time sequence.

[0020] Furthermore, a carrier grating phase is superimposed on the binary amplitude hologram to spatially separate the target diffraction order and the zeroth order light at the target multifocal point array on the focal plane of the Fourier transform lens.

[0021] Furthermore, the digital micromirror device, based on a time-sequentially arranged binary amplitude hologram, adjusts the exposure dose at different exposure focal points independently or in zones by changing the distribution of activated micromirrors, the number of hologram frames, the exposure duty cycle, the number of repeated exposures, or the exposure sequence. The exposure dose is compensated based on the preset local height, curvature, boundary position, local fill rate, adjacent exposure history, or morphological error of the three-dimensional micro / nano structure to reduce the adjacent exposure effect and improve the morphological accuracy of the continuous height micro / nano structure.

[0022] Preferably, the exposure mode of the multiple exposure focal points is one of the following: dot matrix, line array, sparse array, checkerboard, zoned, snake pattern, random, or jump point.

[0023] The beneficial effects of this invention are: This invention employs two continuous laser beams of different wavelengths to act on a two-step absorption photoresist, causing the two-step absorption photoresist to undergo a polymerization reaction in the overlapping area of ​​the two different wavelength light fields. One of the continuous laser beams forms a sheet-like gated light field through a sheet light shaping component, which limits the axial region within the two-step absorption photoresist where a polymerization reaction can occur, thereby reducing the probability of defocus exposure, axial trailing, and polymerization reactions occurring in non-target areas. This invention also utilizes digital micromirror devices for binary amplitude holographic modulation, performs Fourier transform through Fourier transform lenses, and then selects the target multifocal array using a spatial filter aperture. The target multifocal array is then reduced and conjugated to the sample surface within the double-step absorption photoresist by a beam-shrinking conjugate imaging component to form multiple exposure focal points. Therefore, dynamic addressing and parallel exposure of multiple exposure focal points are realized, improving the processing efficiency of three-dimensional micro-nano structures. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the device structure of a sheet-gated multi-focus dynamic addressing three-dimensional micro / nano fabrication system provided in an embodiment of the present invention.

[0025] Figure 2 This is a comparative schematic diagram of a target 8×8 laser beam array and a Fourier surface reconstruction beam array provided in an embodiment of the present invention. (Schematic diagram of the target 8×8 laser beam array) Figure 2(A) Schematic diagram of Fourier surface reconstruction beam array ( Figure 2 (B) in the middle.

[0026] Figure 3 The binary amplitude hologram for generating an 8×8 laser beam array is provided in an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the light field distribution formed by the second continuous laser beam being focused by the sheet light shaping component and the second objective lens, as provided in an embodiment of the present invention. (e.g., a schematic diagram of the sheet-gated light field). Figure 4 (A) , schematic diagram of the light field distribution on the yz plane of the second objective lens focal plane (as shown in Figure 1). Figure 4 (B) , Schematic diagram of the light field distribution on the xz plane of the second objective lens focal plane (as shown in Figure 1). Figure 4 (C) in the middle.

[0028] Figure 5 This is a schematic diagram illustrating the effect of fabricating a three-dimensional micro / nano structure during the writing process provided in an embodiment of the present invention. It also includes a schematic diagram of the fabricated three-dimensional micro / nano structure. Figure 5 (A) in the diagram, current dot matrix distribution diagram ( Figure 5 (B) is a schematic diagram of the trajectory of a certain focal point in the current dot matrix using a snake-like scanning method. Figure 5 (C) in the middle.

[0029] Reference numerals: 101, First laser; 102, First beam expander lens; 103, Second beam expander lens; 104, Reflector; 105, Digital micromirror device; 106, Fourier transform lens; 107, Spatial filter aperture; 108, Beam splitter; 109, Non-polarizing beam splitter prism; 110, Camera; 111, Lens; 112, Light emitting diode; 113, Relay lens; 114, First objective lens; 201, Second laser; 202, Third beam expander lens; 203, Fourth beam expander lens; 204, Sheet beam shaping assembly; 205, Second objective lens; 301, Sample cell; 302, Substrate; 303, Three-dimensional motion submodule. Detailed Implementation

[0030] like Figure 1 As shown in the figure, an embodiment of the present invention provides a sheet-gated multi-focus dynamic addressing three-dimensional micro-nano fabrication system, which includes a first optical path module, a second optical path module and a sample processing module.

[0031] The first optical path module includes a first laser 101, a first beam expander 102, a second beam expander 103, a reflector 104, a digital micromirror device 105, a Fourier transform lens 106, a spatial filter stop 107, a relay lens 113, and a first objective lens 114 arranged sequentially.

[0032] The first beam expander lens 102 and the second beam expander lens 103 are cemented doublet achromatic lenses, and the first beam expander lens 102 and the second beam expander lens 103 form the first beam expander assembly.

[0033] The first continuous laser beam with a wavelength of 450 nm emitted by the first laser 101 is expanded sequentially by the first beam expander lens 102 and the second beam expander lens 103. After expansion, it is emitted to the digital micromirror device 105 via the reflector 104. The digital micromirror device 105 loads a binary amplitude hologram corresponding to the target multifocal array to perform binary amplitude holographic modulation on the incident first continuous laser beam. The modulated first continuous laser beam undergoes Fourier transform by the Fourier transform lens 106, and a diffraction field containing the target multifocal array is formed on the focal plane of the Fourier transform lens 106. Then, the spatial filter aperture 107 selects the target diffraction order where the target multifocal array is located, blocking the zero-order light and non-target diffraction orders. The target multifocal array selected by the spatial filter aperture 107 is reduced and conjugated to the sample surface within the dual-step absorption photoresist supported by the substrate 302 in the sample processing module to form multiple exposure focal points, so as to realize dynamic addressing and parallel exposure of multiple exposure focal points and improve the processing efficiency of three-dimensional micro-nano structures. The beam-conjugate imaging assembly includes a relay lens 113 and a first objective lens 114.

[0034] The first optical path module introduces an illumination observation optical path submodule, which is located between the spatial filter aperture 107 and the beam-conjugate imaging component. The illumination observation optical path submodule includes a beam splitter 108, a non-polarizing beam splitter prism 109, a camera 110, a lens 111, and a light-emitting diode 112. The illumination light emitted by the light-emitting diode 112 is split by the non-polarizing beam splitter prism 109 after passing through the lens 111. One of the split illumination beams is incident on the sample surface in the two-step absorption photoresist in the sample processing module through the beam splitter 108 and the beam-conjugate imaging component for illumination. Subsequently, the reflected light, scattered light, or fluorescence signal on the sample surface passes through the beam-conjugate imaging component and the beam splitter 108, and then passes through the non-polarizing beam splitter prism 109 to the camera 110 for signal acquisition, which is used to observe the exposed area, the polymerization area, or the processed three-dimensional micro-nano structure in the two-step absorption photoresist.

[0035] The second optical path module includes a second laser 201, a third beam expander 202, a fourth beam expander 203, a sheet light shaping assembly 204, and a second objective lens 205 arranged sequentially.

[0036] Among them, the third beam expander lens 202 and the fourth beam expander lens 203 are cemented doublet achromatic lenses, and the third beam expander lens 202 and the fourth beam expander lens 203 form the second beam expander assembly.

[0037] The second continuous laser beam with a wavelength of 640 nm emitted by the second laser 201 is sequentially expanded by the third beam expander lens 202 and the fourth beam expander lens 203. The expanded second continuous laser beam is incident on the sheet light shaping component 204 and introduced into the sample surface within the two-step absorption photoresist supported on the substrate 302 in the sample processing module via the second objective lens 205 to form a sheet-like gated light field. In this embodiment, the sheet light shaping component is a Powell prism.

[0038] The sample processing module includes a sample cell 301, a substrate 302, and a three-dimensional motion submodule 303. The sample cell 301 is used to contain the two-step absorption photoresist, and the substrate 302 is used to support the two-step absorption photoresist. In this embodiment, the three-dimensional motion submodule 303 is a three-dimensional piezoelectric moving platform used to dynamically adjust the substrate to achieve micron- or nanometer-level displacement.

[0039] When multiple exposure focal points generated by the first optical path module and the sheet-gated light field generated by the second optical path module are incident on the sample surface within the dual-step absorption photoresist, the digital micromirror device 105 and the three-dimensional motion submodule 303 work together to achieve the overlap of the sheet-gated light field and multiple exposure focal points on the sample surface. In the overlapping area, an effective polymerization reaction occurs under the combined action of two different wavelength continuous laser beams, and the particles are distributed according to the preset three-dimensional micro-nano structure.

[0040] By intersecting the optical axis of the first objective lens 114 of the first optical path module with the optical axis of the second objective lens 205 of the second optical path module, and by intersecting the optical axis direction of the first objective lens 114 with the thickness direction of the sheet-like gated light field, the axial region where the polymerization reaction occurs within the dual-step absorption photoresist is defined, thereby reducing the probability of defocus exposure, axial trailing, and polymerization reactions occurring in non-target areas.

[0041] This invention also provides a multi-focus dynamic addressing three-dimensional micro / nano fabrication method with sheet-gated technology. The multi-focus dynamic addressing three-dimensional micro / nano fabrication method using the multi-focus dynamic addressing three-dimensional micro / nano fabrication system provided in the above embodiments includes: S1. Generate a binary amplitude hologram arranged in time sequence according to the preset three-dimensional micro-nano structure, and place the two-step absorption photoresist on the substrate 302. Simultaneously start the first laser 101 and the second laser 201 to emit the first continuous light laser beam and the second continuous light laser beam corresponding to the two-step absorption wavelength of the two-step absorption photoresist, respectively.

[0042] The two-step absorption photoresist comprises the monomer dipentaerythritol hexaacrylate (DPEHA) at a mass percentage of 98.7 wt.%, the photoinitiator 2,3-butanedione (Biacetyl) at a mass percentage of 1.1 wt.%, and the radical modulator (2,2,6,6-tetramethylpiperidin-1-yl)oxy radical (TEMPO) at a mass percentage of 0.2 wt.%. The continuous laser beams emitted by the first laser 101 and the second laser 201 have wavelengths of 450 nm and 640 nm, respectively.

[0043] Specifically, the three-dimensional micro / nano structure slice is divided into multiple two-dimensional processing layers, and each two-dimensional processing layer is discretized into multiple target exposure points. These target exposure points are arranged according to a preset rule to form a target 8×8 laser beam array, such as... Figure 2 As shown in (A) in the diagram.

[0044] Based on the position of the target exposure point, the complex amplitude optical field corresponding to the target 8×8 laser beam array is calculated, and an inverse Fourier transform is performed on the complex amplitude optical field to obtain the holographic optical field distribution required by the digital micromirror device 105. Since each micromirror of the digital micromirror device 105 can usually only be in an on or off state, the holographic optical field distribution is binarized to obtain a binary amplitude hologram, such as... Figure 3 As shown.

[0045] Each two-dimensional processing layer is processed sequentially to form a binary amplitude hologram arranged in time sequence. A carrier grating phase is superimposed on the binary amplitude hologram to spatially separate the target diffraction order and the zeroth order light of the target 8×8 laser beam array on the focal plane of the Fourier transform lens.

[0046] S2. The first continuous light laser beam is incident on the digital micromirror device 105 and is subjected to binary amplitude holographic modulation based on the binary amplitude hologram. The modulated first continuous light laser beam is incident on the Fourier transform lens 106 for Fourier transform and then the target multifocal array is selected by the spatial filter aperture 107. The target multifocal array is reduced and conjugated by the beam shrinking conjugate imaging component to form multiple exposure focal points. The second continuous light laser beam is incident on the sheet light shaping component 204 to form a sheet-like gated light field.

[0047] Specifically, the first continuous laser beam is expanded sequentially by the first beam expander lens 102 and the second beam expander lens 103, and then emitted to the digital micromirror device 105 through the reflector 104. The digital micromirror device 105 loads a binary amplitude hologram corresponding to the target 8×8 laser beam array to perform binary amplitude holographic modulation on the incident first continuous laser beam. The modulated first continuous laser beam undergoes a Fourier transform through the Fourier transform lens 106, and a reconstructed Fourier surface reconstructed beam array containing the target 8×8 laser beam array is formed at the focal plane of the Fourier transform lens 106, such as... Figure 2 As shown in (B) in the diagram.

[0048] This indicates that the Fourier surface reconstruction beam array and the target 8×8 laser beam array have the same spatial distribution, the focal positions are regularly arranged, and the focal intensity is relatively uniform. Furthermore, the light intensity uniformity of the Fourier surface reconstruction beam array is greater than 97%, which shows that the binary amplitude hologram can effectively generate a uniform multi-focal exposure array.

[0049] The spatial filter stop 107 is used to select the target diffraction order where the target multifocal array is located, blocking the zero-order light and non-target diffraction orders. The Fourier reconstructed beam array is passed through the spatial filter stop 107 to select the target multifocal array. The target multifocal array is reduced and conjugated to the sample surface within the double-step absorption photoresist by the relay lens 113 and the first objective lens 114 to form multiple exposure focal points, so as to realize dynamic addressing and parallel exposure of multiple exposure focal points, thereby improving the processing efficiency of three-dimensional micro-nano structures.

[0050] like Figure 4 As shown in (A), the second continuous light laser beam is expanded sequentially by the third beam expander lens 202 and the fourth beam expander lens 203. The expanded second continuous light laser beam is incident on the sheet light shaping component 204 and introduced into the sample surface in the double-step absorption photoresist through the second objective lens 205 to form a sheet-like gated light field.

[0051] like Figure 4 As can be seen in (B) and (C), the second continuous laser beam maintains a continuous intensity distribution after being shaped by the sheet light shaping component 204, and its energy is mainly concentrated near the optical axis. Furthermore, near the focal plane of the second objective lens 205, the sheet-gated light field has a large coverage area in the lateral direction, while the effective area along the optical axis is limited. In the light field distribution near the focal planes of the yz and xz planes, it can be observed that the sheet-gated light field forms a thin axial intensity distribution near the focal plane region, and its energy is mainly concentrated within a certain thickness range near the focal plane.

[0052] S3. Multiple exposure focal points and sheet-like gated light fields are incident on the sample surface within the dual-step absorption photoresist. The digital micromirror device and the three-dimensional motion submodule work together to achieve the overlap of the sheet-like gated light field and multiple exposure focal points on the sample surface based on the binary amplitude hologram, and the polymerization reaction only occurs in the overlapping area.

[0053] Specifically, when multiple exposure focal points generated by the first optical path module and the sheet-like gated light field generated by the second optical path module are incident on the sample surface within the dual-step absorption photoresist, and act on different absorption processes of the dual-step absorption photoresist, the polymerization efficiency of the dual-step absorption photoresist when the first and second continuous laser beams of different wavelengths act together is higher than the polymerization efficiency when either continuous laser beam acts alone. Furthermore, the sheet-like gated light field formed by the second continuous laser beam defines the axial region within the dual-step absorption photoresist where polymerization can occur, reducing the probability of defocus exposure, axial trailing, and polymerization reactions occurring in non-target areas.

[0054] The digital micromirror device 105 and the three-dimensional motion submodule 303 work synergistically to achieve the overlap of a sheet-like gated light field with multiple exposure focal points on the sample surface. In the overlapping region, an effective polymerization reaction occurs under the combined action of two continuous laser beams of different wavelengths, and the resulting structures are distributed according to a pre-defined three-dimensional micro / nano structure. Figure 5 As shown in (A) in the diagram.

[0055] like Figure 5 As shown in (B) in the diagram, this represents the current distribution of the dot matrix; as... Figure 5 As shown in (C), the trajectory of a certain focal point in the current dot matrix is ​​scanned using a snake-like exposure method.

[0056] S4. The digital micromirror device 105 performs binary amplitude holographic modulation on the first continuous laser beam by switching binary amplitude holograms in sequence, and dynamically adjusts the substrate based on the three-dimensional motion submodule 303 to complete the fabrication of three-dimensional micro-nano structures one by one.

Claims

1. A sheet-gated, multi-focal, dynamically addressed 3D micro / nano fabrication system, characterized in that, include: The first optical path module includes a first laser, a digital micromirror device, a Fourier transform lens, a spatial filter aperture, and a beam-conjugate imaging component arranged sequentially. The first continuous laser beam emitted by the first laser is incident on the digital micromirror device for binary amplitude holographic modulation. The modulated first continuous laser beam is subjected to Fourier transform by the Fourier transform lens and then the target multifocal array is selected by the spatial filter aperture. The target multifocal array is reduced and conjugated by the beam shrinking and conjugating component to form multiple exposure focal points. The second optical path module includes a second laser and a sheet light shaping component arranged in sequence. The second continuous laser beam emitted by the second laser is incident on the sheet light shaping component to form a sheet-shaped gated optical field. The sample processing module includes a substrate and a three-dimensional motion submodule. The substrate carries a two-step absorption photoresist. Multiple exposure focal points generated by the first optical path module and a sheet-like gated light field generated by the second optical path module are respectively incident on the sample surface within the two-step absorption photoresist. The wavelengths of the first continuous laser beam and the second continuous laser beam correspond to the two absorption wavelengths of the two-step absorption photoresist. The digital micromirror device and the three-dimensional motion submodule work together to achieve the overlapping and aggregation of the sheet-like gated light field and multiple exposure focal points on the sample surface and their distribution according to a preset three-dimensional micro / nano structure.

2. The multi-focal dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, A first beam expander is provided between the first laser and the digital micromirror device, and the first continuous laser beam emitted by the first laser is expanded by the first beam expander. A second beam expander is provided between the second laser and the sheet light shaping component, and the second continuous laser beam emitted by the second laser is expanded by the second beam expander.

3. The multi-focus dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, The first optical path module further includes an illumination and observation optical path submodule, which is disposed between the spatial filter aperture and the beam-conjugate imaging component. The illumination and observation optical path submodule includes a beam splitter, a non-polarizing beam splitter prism, a camera, a lens, and a light-emitting diode. The light-emitting diode emits illumination light, which is split by the non-polarizing beam splitter prism through the lens. One of the split illumination beams is incident on the sample surface within the two-step absorption photoresist in the sample processing module for illumination through the beam splitter and the beam-conjugate imaging component. The reflected light, scattered light, or fluorescence signal on the sample surface passes through the beam-conjugate imaging component and the beam splitter, and then through the non-polarizing beam splitter prism to the camera for signal acquisition, which is used to observe the exposed area, the polymerization area, or the processed three-dimensional micro / nano structure in the two-step absorption photoresist.

4. The multi-focus dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, The beam-conjugate imaging component of the first optical path module includes a relay lens and a first objective lens; The second optical path module also includes a second objective lens, which is used to introduce the sheet-like gated light field formed by the sheet light shaping component into the sample surface within the two-step absorption photoresist; The optical axis of the first objective lens intersects the optical axis of the second objective lens, and the optical axis direction of the first objective lens intersects the thickness direction of the sheet-like gated light field.

5. The multi-focal dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, The sheet light shaping component is one of a cylindrical lens, a Powell lens, a cylindrical lens group, a scanning beam shaping component, a Bessel beam generating component, or a spatial light modulation component.

6. The multi-focus dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, The sample processing module also includes a sample cell for accommodating the two-step absorption photoresist.

7. The multi-focus dynamic addressing three-dimensional micro / nano fabrication system according to claim 1, characterized in that, The three-dimensional motion submodule includes one of the following: a three-dimensional moving platform, a piezoelectric moving platform, or an inertial piezoelectric platform.

8. A method for multi-focus dynamic addressing three-dimensional micro / nano fabrication with sheet-gated light, characterized in that, The multi-focus dynamic addressing three-dimensional micro / nano fabrication system according to any one of claims 1-7, wherein the multi-focus dynamic addressing three-dimensional micro / nano fabrication method comprises: S1. Generate a binary amplitude hologram arranged in time sequence based on the three-dimensional micro-nano structure, place the two-step absorption photoresist on the substrate, and simultaneously start the first laser and the second laser to emit the first continuous light laser beam and the second continuous light laser beam corresponding to the two-step absorption wavelength of the two-step absorption photoresist, respectively. S2. The first continuous laser beam is incident on the digital micromirror device and subjected to binary amplitude holographic modulation based on the binary amplitude hologram. The modulated first continuous laser beam is incident on the Fourier transform lens for Fourier transform, and then the target multifocal array is selected by the spatial filter aperture. The target multifocal array is reduced and conjugated by the beam-shrinking conjugate imaging component to form multiple exposure focal points. The second continuous laser beam is incident on the sheet light shaping component to form a sheet-like gated light field. S3. The multiple exposure focal points and the sheet-like gated light field are respectively incident on the sample surface in the double-step absorption photoresist. The digital micromirror device and the three-dimensional motion submodule work together to realize that the sheet-like gated light field and the multiple exposure focal points overlap on the sample surface according to the binary amplitude hologram, and convergence only occurs in the overlapping area. S4. The digital micromirror device performs binary amplitude holographic modulation on the first continuous laser beam by switching binary amplitude holograms in a time sequence, and dynamically adjusts the substrate based on the three-dimensional motion submodule to complete the processing of the three-dimensional micro-nano structure one by one.

9. The multi-focus dynamic addressing three-dimensional micro / nano fabrication method according to claim 8, characterized in that, The first and second continuous laser beams have different wavelengths, and the two wavelengths are respectively matched to the two-step absorption response process of the two-step absorption photoresist, so that the polymerization efficiency of the two-step absorption photoresist when the first and second continuous laser beams of different wavelengths work together is higher than the polymerization efficiency when either continuous laser beam works alone. Furthermore, the sheet-like gated light field formed by the second continuous laser beam is used to define the axial region within the two-step absorption photoresist where polymerization reactions can occur, thereby reducing the probability of defocusing exposure, axial trailing, and polymerization reactions occurring in non-target areas.

10. The multi-focus dynamic addressing three-dimensional micro / nano fabrication method according to claim 8, characterized in that, The three-dimensional micro / nano structure slice is divided into multiple two-dimensional processing layers, and each two-dimensional processing layer is discretized into multiple target exposure points. Based on the position of the target exposure points, the corresponding binary amplitude hologram is calculated to form a binary amplitude hologram arranged in time sequence. The carrier grating phase is superimposed on the binary amplitude hologram to spatially separate the target diffraction order and the zeroth order light at the target multifocal point array on the focal plane of the Fourier transform lens.

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