Method for manufacturing glass three-dimensional microstructure and apparatus for manufacturing glass three-dimensional microstructure

Abstract

The application provides a glass three-dimensional microstructure preparation method and device. The method comprises the following steps: obtaining a target three-dimensional structure to be prepared, and determining a target curved surface according to the target three-dimensional structure; determining the coordinates of a plurality of target light points according to the target curved surface; determining the phases corresponding to each target light point according to the coordinates of the target light points; determining a plurality of holographic phase patterns according to the phases of all the target light points; modulating a processing light beam through the holographic phase patterns, so that the processing light beam is modulated into a multifocal spot corresponding to each holographic phase pattern in sequence; ablating a base material through the multifocal spot, so as to form an ablation point at the position of each target light point inside the base material; and performing chemical corrosion on the base material, so as to connect the ablation points and form the target three-dimensional structure. Through laser ablation and chemical corrosion, the three-dimensional microstructure can be efficiently prepared. Through chemical corrosion, the surface roughness of the three-dimensional microstructure is reduced, and the smoothness of the surface is improved. Therefore, the high-precision glass three-dimensional microstructure can be efficiently prepared.

Description

Technical Field

[0001] This application relates to the field of laser processing technology, specifically to a method and apparatus for preparing glass three-dimensional microstructures. Background Technology

[0002] With the development of technology, the demand for miniaturization and high precision in equipment is increasing, making micro-nano fabrication technology increasingly important. Glass, with its excellent chemical stability and high-temperature resistance, has become the preferred material carrier for micro-nano structures.

[0003] Existing methods for micro / nano fabrication are generally divided into additive manufacturing and subtractive manufacturing. Additive manufacturing includes 3D printing and inkjet printing, but 3D printing is limited by the materials used, generally only able to fabricate micro / nano structures made of polymer materials such as ABS and PLA, and cannot fabricate three-dimensional glass structures. Furthermore, 3D printing is time-consuming and has a limited scope of application when fabricating large-area samples. Inkjet printing cannot accurately shape ink droplets, resulting in low precision of the fabricated micro / nano structures. Subtractive manufacturing includes diamond turning, laser direct writing, focused ion beam (FIB) machining, and photolithography. However, diamond turning is prone to stress damage when machining hard and brittle materials like glass; laser direct writing requires a displacement stage and a high-power laser beam for single-point processing, resulting in low processing efficiency and limitations due to the precision of the stage, making it difficult to fabricate high-precision micro / nano structures; focused ion beams lack penetrating power and cannot perform three-dimensional processing on the interior of glass; photolithography can only fabricate simple two-dimensional structural features in a single exposure, and the three-dimensional structures fabricated through multi-layer overlay processes are mostly stepped, unable to produce continuously changing true three-dimensional structures. In the existing technology, there is a lack of a method for high-precision processing of glass to efficiently prepare high-precision three-dimensional micro / nano structures on glass substrates. Summary of the Invention

[0004] To address the aforementioned issues, this application proposes a method and apparatus for preparing three-dimensional glass microstructures, which can efficiently produce high-precision three-dimensional glass microstructures.

[0005] The first aspect of this application provides a method for preparing a three-dimensional glass microstructure, the method comprising:

[0006] Obtain the target three-dimensional structure to be prepared, and determine the target surface based on the target three-dimensional structure, wherein the target surface is the upper or lower surface of the target three-dimensional structure;

[0007] The coordinates of multiple target light points are determined based on the target surface, wherein each target light point is a point on the target surface;

[0008] The phase corresponding to each target light point is determined based on the coordinates of the target light points;

[0009] Multiple holographic phase maps are determined based on the phase of all the target light points;

[0010] The processing beam is modulated sequentially by the multiple holographic phase maps to form a multifocal spot corresponding to each holographic phase map.

[0011] The substrate is ablated by the multi-focus light spot to form ablation points at the location of each target light spot inside the substrate.

[0012] The substrate is chemically etched to connect the ablation points and form the target three-dimensional structure.

[0013] In some embodiments, determining the coordinates of multiple target light points based on the target surface includes:

[0014] If the target surface is a rotationally symmetric surface, obtain the equation of the generatrix of the rotationally symmetric surface;

[0015] The coordinates of each target light point are determined based on the aforementioned generatrix equation.

[0016] In some embodiments, determining multiple holographic phase maps based on the phases of all the target light points includes:

[0017] When the target surface is a rotationally symmetric surface, a first holographic phase map is determined based on the phase corresponding to each target light point on the generatrix of the target surface;

[0018] The first holographic phase image is rotated according to a preset step angle to obtain multiple sets of the holographic phase images.

[0019] In some embodiments, the step of sequentially modulating the beam using the plurality of holographic phase maps includes:

[0020] When the target surface is a rotationally symmetric surface, a diffractive optical element is fabricated based on the first holographic phase map;

[0021] The light beam is modulated by the diffractive optical element to form a multifocal light spot distributed according to the generatrix of the target surface;

[0022] During the process of modulating the light beam through the diffractive optical element, the diffractive optical element is rotated at a preset rotation speed to make the multifocal spot rotate, forming the multifocal spot corresponding to the position of the generatrix of the target surface after rotation.

[0023] In some embodiments, determining the coordinates of multiple target light points based on the target surface includes:

[0024] When the target surface is a non-rotationally symmetric surface, a corresponding three-dimensional mesh is determined based on the target surface;

[0025] The coordinates of each target light point are determined based on the coordinates of each grid point in the three-dimensional mesh diagram.

[0026] In some embodiments, determining multiple holographic phase maps based on the phases of all the target light points includes:

[0027] When the target surface is a non-rotationally symmetric surface, the target light spot is divided into multiple subsets.

[0028] The holographic phase map corresponding to each of the sub-point sets is determined based on the phase of the target light point in each sub-point set.

[0029] In some embodiments, the step of sequentially modulating the beam using the plurality of holographic phase maps includes:

[0030] Multiple sets of the holographic phase images are loaded into a spatial light modulator, and each holographic phase image is played sequentially in the spatial light modulator to modulate the light beam into a multifocal spot corresponding to each holographic phase image.

[0031] In some embodiments, determining the phase corresponding to each target light point based on the coordinates of the target light points includes:

[0032] The deflection and focusing depth of the target light spot are determined based on its coordinates.

[0033] The first phase of the blazed grating required to deflect the processing beam to the target spot position is determined based on the deflection amount.

[0034] The second phase of the lens required to focus the processing beam at the target spot is determined based on the focusing depth.

[0035] The phase corresponding to the target light spot is determined based on the first phase and the second phase.

[0036] In some embodiments, before determining the phase corresponding to each of the target light points based on the coordinates of the target light points, the method further includes:

[0037] The coordinates of the target light spot are corrected based on the refractive index of the substrate.

[0038] A second aspect of this application provides an apparatus for fabricating three-dimensional glass microstructures, the apparatus comprising:

[0039] The controller is used to acquire the target three-dimensional structure to be prepared, determine the target surface based on the target three-dimensional structure, and determine the coordinates of multiple target light points based on the target surface. The controller is also used to determine the phase corresponding to each target light point based on the coordinates of the target light points and to determine multiple holographic phase maps based on the phases of all the target light points.

[0040] The beam shaping module includes a modulation unit and a focusing unit. The modulation unit is used to modulate the processing beam according to multiple holographic phase diagrams, and the focusing unit is used to focus the modulated processing beam to form a multifocal spot.

[0041] A stage for supporting the substrate, wherein the stage is positioned in the direction in which the focusing unit emits the multifocal light spot;

[0042] The etching module is used to chemically etch the ablated substrate to connect the ablation points and form the target three-dimensional structure.

[0043] This application provides a method and apparatus for fabricating a three-dimensional glass microstructure. The method includes: acquiring a target three-dimensional structure to be fabricated, and determining a target surface based on the target three-dimensional structure, wherein the target surface is the upper or lower surface of the target three-dimensional structure; determining the coordinates of multiple target light points based on the target surface, wherein each target light point is a point on the target surface; determining the phase corresponding to each target light point based on the coordinates of the target light points; determining multiple holographic phase maps based on the phases of all the target light points; sequentially modulating a processing beam using the multiple holographic phase maps to modulate the processing beam into a multifocal spot corresponding to each holographic phase map; ablating a substrate using the multifocal spot to form an ablation point at the position of each target light point within the substrate; and chemically etching the substrate to connect the ablation points to form the target three-dimensional structure. This application embodiment obtains the upper or lower surface of the target three-dimensional surface as the target surface, takes points from the target surface to obtain multiple target light points, and determines the coordinates of each target light point. Based on the coordinates of each target light point, it determines the phase modulation information required to generate the target light point. Based on the phase corresponding to each target light point, it generates multiple holographic phase maps. The processing beam is modulated sequentially using multiple holographic phase maps, and the processing beam is sequentially modulated into a multi-focal spot corresponding to each holographic phase map. The processing beam is then used to irradiate the substrate through the multi-focal spot, forming ablation points in the substrate. For three-dimensional microstructures of different shapes, only their corresponding target surfaces need to be obtained, thereby obtaining... The corresponding holographic phase map can be obtained, which improves the flexibility in preparing different three-dimensional microstructures. After the substrate is ablated and a large number of ablation points are distributed according to the target surface, the substrate is placed in the etching solution for etching, so that the ablation points are connected to form the target surface, thereby dividing the substrate and forming the target three-dimensional structure. Thus, the substrate is processed by laser ablation combined with chemical etching, without having to ablate the complete target surface from the surface to the interior of the substrate by a processing beam, which improves the processing efficiency. At the same time, the polishing effect of chemical etching can be used to reduce the surface roughness of the formed surface and ensure the surface quality of the prepared three-dimensional microstructure.

[0044] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0045] Figure 1 This is a flowchart of a method for preparing a three-dimensional glass microstructure according to an embodiment of this application;

[0046] Figure 2 yes Figure 1Sub-flowchart of step S102;

[0047] Figure 3 yes Figure 1 Sub-flowchart of step S102;

[0048] Figure 4 This is a flowchart illustrating another method for preparing three-dimensional glass microstructures proposed in this application.

[0049] Figure 5 yes Figure 1 Sub-flowchart of step S103;

[0050] Figure 6 yes Figure 1 Sub-flowchart of step S104;

[0051] Figure 7 yes Figure 1 Sub-flowchart of step S104;

[0052] Figure 8 yes Figure 1 Sub-flowchart of step S105;

[0053] Figure 9 This is a schematic diagram of the structure of a glass three-dimensional microstructure fabrication device proposed in the embodiments of this application;

[0054] Figure 10 This is a schematic diagram of another glass three-dimensional microstructure fabrication device proposed in the embodiments of this application;

[0055] Figure 11 This is a schematic cross-sectional view of a hemispherical structure prepared by the glass three-dimensional microstructure preparation method proposed in the embodiments of this application;

[0056] Figure 12 This is a schematic cross-sectional view of a conical structure prepared by the glass three-dimensional microstructure preparation method proposed in the embodiments of this application;

[0057] Figure 13 This is a cross-sectional schematic diagram of a square pyramid structure prepared by the glass three-dimensional microstructure preparation method proposed in the embodiments of this application;

[0058] Figure 14 This is a schematic cross-sectional view of an elliptical hemispherical structure prepared by the glass three-dimensional microstructure preparation method proposed in the embodiments of this application;

[0059] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0061] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0063] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0064] Reference Figure 1 The first aspect of this application provides a method for preparing a three-dimensional glass microstructure, comprising:

[0065] Step S101: Obtain the target three-dimensional structure to be prepared, and determine the target surface based on the target three-dimensional structure. The target surface is the upper or lower surface of the target three-dimensional structure.

[0066] Step S102: Determine the coordinates of multiple target light points based on the target surface, wherein each target light point is a point on the target surface;

[0067] Step S103: Determine the phase corresponding to each target light point based on the coordinates of the target light points;

[0068] Step S104: Determine multiple holographic phase maps based on the phases of all target light points;

[0069] Step S105: The processing beam is modulated sequentially by multiple holographic phase images to modulate the processing beam into a multifocal spot corresponding to each holographic phase image.

[0070] Step S106: The substrate is ablated by multi-focus light spots to form ablation points at the location of each target light spot inside the substrate;

[0071] Step S107: Chemically etch the substrate to connect the ablation points and form the target three-dimensional structure.

[0072] In step S101 of some embodiments, the target three-dimensional structure refers to a three-dimensional microstructure to be formed by processing the glass substrate. Specifically, it can be a three-dimensional structure formed by the remaining glass substrate after removing a portion of the material, such as a substrate with irregular grooves on the surface or a substrate with a specific optical surface. Alternatively, the target three-dimensional structure can be a three-dimensional structure presented by the portion detached from the glass substrate, such as a micro-concave lens, a convex lens, or a micro-cylinder. It is understood that the glass substrate can be a cuboid-shaped substrate. Based on the target three-dimensional structure, its upper or lower surface is obtained as the target surface. It is understood that when the target three-dimensional structure is the portion remaining in the glass substrate, the target surface is the upper surface of the target three-dimensional structure, and when the target three-dimensional structure is the portion detached from the glass substrate, the target surface is the lower surface of the target three-dimensional structure.

[0073] In step S102 of some embodiments, the target light spot refers to a point falling on the target curved surface. The coordinates of the target light spot refer to the coordinates of the target light spot in a coordinate system constructed with the origin of the modulated processing beam emission point as the origin (i.e., the intersection of the objective lens exit surface and the principal optical axis as the origin), the normal direction of the upper surface of the substrate as the z-direction, and any two orthogonal directions on the upper surface of the substrate as the x-direction and y-direction. It can be understood that the coordinates of all target light spots are determined based on the same spatial coordinate system. By taking points on the target curved surface, the coordinates of multiple target light spots can be obtained. When all target light spots are connected with other adjacent target light spots, a target curved surface can be formed. It can be understood that, in order to ensure the accuracy of the processed three-dimensional microstructure of glass, it is necessary to ensure that the distance between the target light spot and other adjacent target light spots is small enough. For example, the distance between two adjacent target light spots should be less than a set threshold. Specifically, since the energy of the laser is relatively concentrated at the positions before and after the focal point, this will cause the processing beam to produce a certain ablation effect on the position before and after the focal point in the axis of the processing beam when ablating the substrate. This will make the ablation point spindle-shaped in the axis of the processing beam. In this embodiment, the axis of the processing beam is the z-direction. Based on this, the maximum distance between two adjacent target light spots in the z-direction can be less than 8 micrometers, and the maximum distance in the horizontal direction can be less than 3 micrometers. In this way, the distance between the ablation points formed in the axis and horizontal direction of the processing beam is relatively small, which can ensure that the ablation points formed can form an ablation surface that is consistent with the shape of the target surface after being connected, thereby separating the substrate and forming the target three-dimensional structure.

[0074] In step S103 of some embodiments, based on the coordinates of each target light point, the phase information required to refract the light from the exit point to the target light point can be calculated. Specifically, based on the coordinates of the target light point, the first phase of the diffraction grating required to deflect the processing beam toward the target light point and the second phase of the Fresnel lens required to focus the processing beam at the target light point to form an ablation point can be calculated. The first phase and the second phase are then superimposed to obtain the phase information required to focus the processing beam at the coordinates of the target light point, that is, to obtain the phase corresponding to the target light point.

[0075] In step S104 of some embodiments, multiple holographic phase maps can be determined based on the phase of the target light spot. It is understood that to fabricate high-precision three-dimensional microstructures on a substrate, the processing beam needs to be modulated based on the phase of the target light spot, so that the modulated laser is focused at the position of each target light spot to ablate the substrate, thereby forming a large number of ablation points from the surface to the interior of the substrate. In this embodiment, to improve processing speed, a holographic phase map can be determined based on the phases of multiple target light spots. This holographic phase map contains the phase information of multiple target light spots, and modulating the processing beam based on this holographic phase map can form a multi-focal spot. Understandably, due to the large number of target light spots required for processing high-precision three-dimensional microstructures on a substrate, it is impossible to encompass the phases corresponding to all target light spots with a single holographic phase image. Therefore, multiple holographic phase images are needed, each carrying the phases corresponding to multiple target light spots. For example, each holographic phase image may include the phases corresponding to 15 target light spots. Based on this holographic phase image, the processing beam is modulated so that the emitted beam forms 15 focal spots, which ablate the 15 target light spots. It is also understood that the phase information carried by each holographic phase image is unique; that is, each holographic phase image corresponds to a different set of target light spots.

[0076] In steps S105 and S106 of some embodiments, after obtaining multiple holographic phase images, the processing beam is modulated sequentially using each holographic phase image, so that the modulated processing beam has a target light field distribution corresponding to the holographic phase image. This sequentially modulates the processing beam into a multifocal spot corresponding to each holographic phase image. It is understood that the processing beam can be a Gaussian linearly polarized pulsed laser emitted by an ultrafast laser. In one embodiment, the center wavelength of the Gaussian linearly polarized pulsed laser emitted by the ultrafast laser is 1030 nanometers, and the pulse width of the processing beam can be between 3 picoseconds and 3000 femtoseconds. It is understood that the diameter of the processing beam emitted by the ultrafast laser is... The process is relatively small. A beam expansion and collimation module can be set at the output end of the ultrafast laser to expand the processing beam emitted by the ultrafast laser before modulating the processing beam. After the modulated processing beam is emitted, it is focused by the objective lens and will focus at the position of multiple target light spots corresponding to the holographic phase map. The material at the position is ablated to form ablation points. By switching the holographic phase map at a rated frequency, the processing beam is sequentially modulated into a multi-focal spot corresponding to each holographic phase map. In this way, after the processing beam is modulated sequentially through all holographic phase maps, a large number of ablation points corresponding to the target light spots are ablated in the glass substrate. These ablation points are distributed from the surface to the interior of the substrate according to the shape of the target surface. Based on this, for different target 3D structures, only the upper or lower surface needs to be obtained as the target surface. Points are then taken from this target surface to obtain the coordinates of the target light points. The phase corresponding to each target light point is then determined based on these coordinates, and multiple holographic phase maps are thus established. The processing beam is then modulated using these holographic phase maps, which can form a large number of ablation points distributed along the target surface from the surface to the interior of the substrate. This significantly improves the flexibility in fabricating glass 3D microstructures of different shapes. Furthermore, by modulating the processing beam using the holographic phase map formed by the phases of multiple target light points, a multi-focal spot is created to ablate the substrate, allowing for the simultaneous formation of multiple ablation points and resulting in higher processing efficiency.

[0077] Specifically, multiple holographic phase images can be loaded into the modulation unit, which can be a spatial light modulator. Each holographic phase image is played sequentially in the modulation unit to modulate the processing beam into a multi-focal spot corresponding to each holographic phase image. Specifically, a spatial light modulator is a device that can perform wavefront modulation on an incident laser beam, thereby adjusting the light field distribution of the incident laser by changing the phase and amplitude of the incident laser. It includes a large number of independent micro-pixels, each of which can be used to change the phase of the laser. After the holographic phase images are loaded into the spatial light modulator, the spatial light modulator will adjust the state of each micro-pixel according to the loaded holographic phase images, simulating the phase with the loaded holographic phase images in space. This causes the injected processing beam to be emitted and deflected according to the shape corresponding to the holographic phase images, and then focused by the objective lens at the target light point. In some embodiments, a 4f transmission system consisting of two opposing plano-convex lenses with the same focal length can also be set between the modulation unit and the objective lens to move the processing beam emitted from the spatial light modulator to the objective lens with high fidelity. In this embodiment, each holographic phase image contains the phases of multiple target light points. Modulating the processing beam based on these holographic phase images allows for beam splitting and simultaneous focusing at the positions of the multiple target light points corresponding to the holographic phase images, forming multifocal spots. After loading multiple holographic phase images onto a spatial light modulator, the playback function of the spatial light modulator can switch the holographic phase images used to modulate the processing beam at a certain frequency, modulating the wavefront phase of the processing beam to match the phase information contained in the corresponding holographic phase image, thereby sequentially forming multifocal spots consistent with the phase information of each holographic phase image. It is understood that multiple reflectors can also be set in the propagation optical path of the processing beam to fold the propagation optical path, thereby reducing the overall size of the glass three-dimensional microstructure fabrication device.

[0078] In step S107 of some embodiments, the processing beam is modulated using multiple holographic phase maps to form a large number of ablation points from the surface to the interior of the substrate. The substrate is then placed in an etching solution for etching. Under the chemical etching action and concentration stress of the etching solution, the ablation points can connect with each other. When all the ablation points are connected, a continuous surface with the same shape as the target surface is formed from the surface to the interior of the substrate. This surface divides the substrate into two parts: a part surrounded by the target surface and detached from the substrate, and a part remaining in the substrate. One of these parts is the desired target three-dimensional structure. Specifically, if the target surface is the lower surface of the target three-dimensional structure, the part detached from the substrate is the target three-dimensional structure; if the target surface is the upper surface of the target three-dimensional structure, the part remaining in the substrate is the target three-dimensional structure. It should be noted that the glass structure formed by chemical etching in this embodiment has relatively low surface roughness, and the surface quality of the prepared three-dimensional microstructure is higher than that of the three-dimensional microstructure formed by laser direct writing ablation. Based on this, in this embodiment, by using multi-focus spot ablation of the substrate in conjunction with chemical etching, the processing beam does not need to process the complete target surface from the surface to the interior of the substrate, but only needs to form multiple ablation points distributed according to the target surface. This greatly reduces the difficulty of the laser ablation process and saves processing time. Furthermore, by utilizing the polishing effect of chemical etching, the roughness of the target surface is reduced, and high-quality three-dimensional microstructures are prepared.

[0079] In this embodiment, the upper or lower surface of the target three-dimensional structure is used as the target surface. Points are taken from the target surface to obtain multiple target light points and determine the coordinates of each target light point. Based on the coordinates of each target light point, the phase modulation information required to generate the target light point is determined. Based on the phase corresponding to each target light point, multiple holographic phase maps are generated. The processing beam is modulated sequentially using the multiple holographic phase maps, and the processing beam is sequentially modulated into a multi-focal spot corresponding to each holographic phase map. The multi-focal spot is then used to irradiate the substrate, forming ablation points in the substrate. For three-dimensional microstructures of different shapes, only their corresponding target surfaces need to be obtained. This allows for the acquisition of the corresponding holographic phase map, improving the flexibility in fabricating different three-dimensional microstructures. After ablation of the substrate to obtain a large number of ablation points distributed according to the target surface, the substrate is then placed in an etching solution for further etching. This allows the ablation points to connect with each other to form the target surface, thereby segmenting the substrate and forming the target three-dimensional structure. Thus, the substrate is processed by combining laser ablation with chemical etching, eliminating the need to ablate the entire target surface from the surface to the interior of the substrate using a processing beam. This improves processing efficiency. At the same time, the polishing effect of chemical etching can be used to reduce the surface roughness of the formed surface, ensuring the surface quality of the fabricated three-dimensional microstructure.

[0080] Reference Figure 2In some embodiments, step S102 includes, but is not limited to, the following steps S201 to S202.

[0081] Step S201: If the target surface is a rotationally symmetric surface, obtain the generatrix equation of the rotationally symmetric surface;

[0082] Step S202: Determine the coordinates of each target light point according to the generatrix equation.

[0083] It is understandable that a rotationally symmetric surface is a surface obtained by rotating a straight line or curve around a given axis of symmetry, such as the lateral surface of a sphere, cone, or cylinder. By analyzing the target surface, it can be determined whether it is a rotationally symmetric surface. If so, its axis of rotation is obtained, and a plane can be extended from this axis of rotation. The equation of the intersection line between this plane and the target surface is the generatrix equation of the rotationally symmetric surface. Specifically, the extended plane can be a plane parallel to the xOz plane. In this case, the y-values ​​of all points on the generatrix equation are equal. At this time, the generatrix equation of the rotationally symmetric surface can be expressed as z = f(x). Thus, determining the coordinates of the target light point from a three-dimensional surface can be simplified to determining the coordinates of the target light point from a two-dimensional curve, effectively reducing the complexity of determining the coordinates of the target light point from the target surface. It is understood that the spatial coordinate system used in this embodiment can refer to the spatial coordinate system mentioned in step S102 of the above embodiment, and will not be repeated here.

[0084] In step S202 of some embodiments, after obtaining the generatrix equation of the rotationally symmetric surface, the coordinates of multiple target light points can be determined based on the generatrix equation. Specifically, in this embodiment, the generatrix equation of the rotationally symmetric surface can be expressed as z = f(x). For any x within a given range, the corresponding z value can be obtained. Thus, the coordinates of multiple target light points can be obtained based on the generatrix equation of the rotationally symmetric surface, wherein the coordinates of the j-th target light point can be expressed as (x... j ,z jSpecifically, the lower limit X1 and upper limit X2 can be determined based on the generatrix equation of the rotationally symmetric surface. Points are taken at given intervals t within the interval [X1, X2] to obtain a set of x-coordinates [X1, X1+t, X1+2t, X1+3t, ..., X2]. These x-coordinates are then substituted into the generatrix equation of the rotationally symmetric surface to determine the z-coordinate corresponding to each x-coordinate. In this way, the coordinates of a set of target light points can be determined based on the generatrix equation of the rotationally symmetric surface. This reduces the difficulty of determining the coordinates of target light points from the target surface and ensures that the obtained target light points are uniformly distributed on the target surface. This results in uniformly ablated points distributed according to the generatrix shape of the target surface in the substrate, improving the smoothness of the target surface formed after etching. It is understandable that, in this embodiment, the lower limit Z1 and upper limit Z2 can also be determined based on the generatrix equation of the rotationally symmetric surface, and points can be taken in the z-direction at given intervals t. These points are then substituted into the generatrix equation to determine the x-value corresponding to each z-value, thereby determining the coordinates of the target light point. It should be noted that the given interval t should be small enough to ensure that the distance between two adjacent target light points is small, so that the obtained target light points are distributed according to the shape of the target surface. In a feasible embodiment, the given interval t can also be determined in conjunction with the slope of the generatrix of the target surface. For example, when taking the x-coordinate from the interval [X1, X2] based on the interval t, and then substituting the x-coordinate into the generatrix equation to calculate the corresponding z-coordinate of each point, for intervals with a larger slope, when the x-coordinate changes by t, the corresponding z-coordinate changes by a relatively larger margin. At this time, the distance between two adjacent target light points is also larger, so the value of t needs to be reduced to reduce the distance between two adjacent target light points, ensuring that the connected target light points can present the shape of the generatrix of the target surface. For intervals with a smaller slope, when the x-coordinate changes by t, the corresponding z-coordinate changes by a relatively smaller margin. At this time, appropriately increasing the value of t will still result in a smaller distance between two adjacent target light points, and the connected target light points can still present the shape of the generatrix of the target surface. Increasing the interval t can reduce the number of target light points obtained. Thus, while maintaining processing accuracy, the number of points to be ablated can be reduced, the time required for ablation of the substrate can be shortened, and the efficiency of preparing three-dimensional glass microstructures can be improved. It is understandable that, when taking the z-coordinate from the interval [Z1, Z2] according to the interval t, and then substituting the z-coordinate into the generatrix equation to calculate the corresponding x-coordinate of each point, the value of the interval t can be determined by combining the magnitude of the change of the x-coordinate with the z-coordinate. For details, please refer to the above embodiment, which will not be repeated here.

[0085] Reference Figure 3 In some embodiments, step S102 may include, but is not limited to, step S301.

[0086] Step S301: If the target surface is a non-rotationally symmetric surface, determine the corresponding three-dimensional mesh based on the target surface;

[0087] Step S302: Determine the coordinates of each target light point based on the coordinates of each grid point in the three-dimensional grid diagram.

[0088] Understandably, when the target surface is non-rotationally symmetric, the coordinates of the target light point cannot be determined by analyzing the generatrix equation. In this case, the target surface can be divided into multiple tiny sub-surfaces, and these sub-surfaces can be sequentially pieced together to form a 3D mesh corresponding to the target surface. The vertices of each sub-surface are the coordinates of the mesh points in this 3D mesh, and these mesh point coordinates can be used as the coordinates of the target light point. Specifically, a 3D mesh composed of numerous tiny volume elements can be given. This 3D mesh contains many straight lines along the x, y, or z directions. Placing this 3D mesh and the target surface in the same spatial coordinate system, the straight lines in the 3D mesh will intersect with the target surface, forming intersection points. Connecting these intersection points with other adjacent intersection points along the path of the target surface divides the target surface into multiple sub-surfaces, forming a 3D mesh corresponding to the target surface. The coordinates of these intersection points can be regarded as the coordinates of the target light point obtained from the target surface. Yes, in this embodiment, each volume element can be a cuboid, the length, width and height of which are all less than a set threshold. For example, the length, width and height of the cuboid are all less than 1 μm. In this way, the distance between the straight line in the three-dimensional mesh and the adjacent parallel line along the same direction is also small enough. The distance between two adjacent intersection points formed by the intersection of the target surface and the three-dimensional mesh will also be limited to a range less than the length of the volume diagonal of the volume element. Based on this, by taking the intersection point of the three-dimensional mesh and the target surface as the target light point, it can be ensured that the target light points present the shape of the target surface after being connected to each other.

[0089] Reference Figure 4 In some embodiments, step S103 may include, but is not limited to, step S401.

[0090] Step S401: Correct the coordinates of the target light point according to the refractive index of the substrate.

[0091] Understandably, after the processing beam exits the objective lens, it propagates a certain distance in the air before entering the substrate. However, due to refraction at the interface between the air and the substrate, the focal point of the processing beam shifts. This prevents the beam from accurately ablating the target spot. Therefore, to eliminate this shift caused by the change in the beam's propagation interface, the coordinates of the target spot should be corrected based on the refractive index of the substrate before calculating the corresponding phase. Specifically, refer to the following formula:

[0092] z mz =z m *n;

[0093] In the formula, z m It is the z-coordinate of the m-th target light spot before correction, z mz is the z-coordinate of the m-th target spot after correction, and n is the refractive index of the substrate.

[0094] In this embodiment of the application, before calculating the corresponding phase based on the coordinates of the target light spot, the z-coordinate of the target light spot is first corrected based on the refractive index of the substrate. This eliminates the spot focus shift caused by light refraction due to interface changes during the process of the processing beam entering the substrate from the air, so that the modulated processing beam can accurately ablate the target light spot.

[0095] Reference Figure 5 In some embodiments, step S103 may include, but is not limited to, steps S501 to S504.

[0096] Step S501: Determine the deflection and focusing depth of the target light point based on its coordinates;

[0097] Step S502: Determine the first phase of the blazed grating required to deflect the processing beam to the target spot position based on the deflection amount;

[0098] Step S503: Determine the second phase of the lens required to focus the processing beam at the target spot position based on the focusing depth;

[0099] Step S504: Determine the phase corresponding to the target light spot based on the first phase and the second phase.

[0100] In step S501 of some embodiments, the amount of deflection and the depth of focus required to deflect the processing beam emitted from the objective lens to the target light point can be calculated based on the coordinates of the target light point. Specifically, the coordinates of the m-th target light point are (x m ,y m ,z m For example, the deflection of the processing beam in the x-direction is x. m The deflection in the y direction is y m The depth of focus is z m .

[0101] In step S502 of some embodiments, the phase of the desired blazed grating can be calculated based on the deflection amount. Specifically, the diffraction angle of the desired grating can be calculated based on the deflection amount. Based on the diffraction angle, combined with the wavelength of the processing beam and the focal length of the objective lens that focuses the processing beam, the first phase of the blazed grating can be calculated.

[0102] In step S503 of some embodiments, the focusing depth reflects the actual focal length required for the processing beam to form a focal point at the target light spot after being focused by the objective lens. Since the focal length of the objective lens itself is fixed, to ensure that the processing beam forms a focal spot at different focusing depths after passing through the objective lens, it can be first focused by a lens and then propagated to the objective lens for secondary focusing. It can be understood that the focusing effect of the lens is actually the effect of specific wavefront modulation of the beam after passing through the lens. Based on this, the processing beam can be modulated by calculating the phase of a Fresnel lens with a corresponding focal length, so that the modulated processing beam has the wavefront phase of the beam after being focused by the lens once. Specifically, after modulation and focusing by the objective lens, the processing beam is equivalent to being focused twice by the Fresnel lens and the objective lens, and the total effect of these two focusing can be considered as the focusing depth z. m Given that the focal length of the objective lens is a known fixed value, the focal length of the corresponding Fresnel lens can be calculated according to the lens imaging formula, and thus the second phase of the corresponding Fresnel lens can be calculated.

[0103] In step S504 of some embodiments, after calculating the first phase of the corresponding blazed grating and the second phase of the Fresnel lens based on the coordinates of the target light point, the two are superimposed to obtain the phase modulation information required to focus the processing beam at the target light point to form a focal spot. Specifically, refer to the following formula:

[0104]

[0105] In the formula, That is, the phase corresponding to the m-th target light spot. It is the first phase of the blazed grating required to deflect the processing beam toward the target spot. It is the second phase of the Fresnel lens required to make the processing beam form a focal spot at the focusing depth of the target light point.

[0106] In this embodiment, the beam deflection and focusing depth required to generate the target light point are determined based on the coordinates of the target light point. Then, the first phase of the blazed grating required to generate the corresponding deflection of the processing beam and the second phase of the Fresnel lens required to form a focal point at the corresponding focusing depth are determined. The two are superimposed to obtain the phase corresponding to each target light point. Thus, the wavefront of the processing beam can be accurately modulated so that the processing beam forms a corresponding multifocal spot after being focused by the objective lens.

[0107] Reference Figure 6 In some embodiments, step S104 includes, but is not limited to, steps S601 to S602.

[0108] Step S601: When the target surface is a rotationally symmetric surface, determine the first holographic phase map based on the phase corresponding to each target light point on the generatrix of the target surface.

[0109] Step S602: Rotate the first holographic phase image according to a preset step angle to obtain multiple holographic phase images.

[0110] In step S601 of some embodiments, when the target surface is a rotationally symmetric surface, referring to the above embodiments, the coordinates of multiple target light points can be determined according to the generatrix equation of the rotationally symmetric surface. Then, based on the coordinates of the target light points, the first phase of the diffraction grating required to deflect the processing beam toward the target light point and the second phase of the Fresnel lens required to focus the processing beam at the coordinates of the target light point to form an ablation point can be determined. The phase corresponding to each target light point can be determined. Based on the phases of all target light points on a generatrix of the target surface, a holographic phase map can be constructed. Specifically, the first holographic phase map can be obtained by superimposing the phases of all target light points on the generatrix of the target surface, referring to the following formula (1):

[0111]

[0112] In the formula, It is the holographic phase map corresponding to the generatrix of the target surface. It is the phase of the m-th target light point on the bus, M is the number of target light points on the bus, e is the natural base, and i is the imaginary unit.

[0113] In some embodiments, when the number of target light points obtained based on the generatrix equation of the target surface is large, on the one hand, the number of focal points that the spatial light modulator can load at the same time is limited; on the other hand, the target light points obtained based on the generatrix equation of the surface are relatively uniformly distributed. This uniform distribution of target light points will cause moiré patterns in the holographic phase image. Moiré patterns will cause secondary focusing of the processing beam, making it impossible to generate an ideal multifocal spot. Based on this, the target light points can be divided into multiple subsets to destroy the uniformity of the multifocal spot and eliminate the moiré patterns in the holographic phase image. Then, based on the phase of all target light points in each subset, a first holographic phase image corresponding to that subset is determined, thereby obtaining multiple first holographic phase images. It is understood that in this embodiment, the number of target light points in each subset is the same. For example, each subset may include 15 target light points. Thus, each first holographic phase image contains the phase information of 15 target light points, and the sum of all first holographic phase images contains the phase information of all target light points on a generatrix of the target surface.

[0114] In step S302 of some embodiments, after obtaining the first holographic phase map corresponding to all target light points on a generatrix of the target surface, the phase map is then processed according to a preset step angle θ. R The first holographic phase image is rotated. Specifically, the rotation step angle can be determined based on the radius of the arc with the largest radius in the rotationally symmetric surface. It can be understood that to ensure the target light spots can present the shape distribution of the target surface after erosion and connection, the distance between the formed target light spots must be sufficiently small. Therefore, it is necessary to ensure that the maximum distance between the corresponding two target light spots obtained before and after each rotation of the generatrix is ​​less than a preset distance threshold, for example, less than 3 micrometers. This distance can be approximated as the arc length of the arc formed when the light spots on the generatrix rotate according to the step angle. Based on this, the step angle during rotation can be determined based on the radius of the circular section with the largest radius in the rotationally symmetric surface. Therefore, θ... R The value of θ should ensure that the arc length corresponding to the largest radius circular cross-section in the rotationally symmetric surface is less than the preset distance threshold. Taking the processing of a cone as an example, the largest radius circular cross-section is the base of the cone. With the radius of the cone's base as R, and the maximum distance between the two target light points set as x micrometers, then θ R The maximum arc length corresponding to a circle with radius R should not exceed x micrometers. Further combining this with the arc length formula yields the step angle θ. R The range of values ​​for is as follows. It is understandable that when the number of target light points obtained from the generatrix equation of the surface is large, i.e., when it is necessary to group the target light points on the generatrix of the surface to form multiple first holographic phase images, then it is necessary to follow the step angle θ. R Rotate all the first holographic phase images. It can be understood that the center of rotation during the rotation of the first holographic phase image is the point corresponding to the intersection of the generatrix of the target surface and the axis of rotation. This yields holographic phase images corresponding to all target points on the generatrix at different rotation angles. After rotating the first holographic phase image one revolution according to a preset step angle, multiple holographic phase images corresponding to the rotationally symmetric surface are obtained. Each holographic phase image corresponds to the phase of multiple target points at different rotation angles along the generatrix of the target surface.

[0115] In this embodiment, when the target surface is a rotationally symmetric surface, the phases of multiple target light points on the generatrix of the surface are obtained based on the generatrix equation of the rotationally symmetric surface. A first holographic phase map is then constructed using this phase map. The first holographic phase map is then rotated according to a preset step angle to obtain multiple holographic phase maps corresponding to different rotation angles of the generatrix of the target surface. In this way, when the target surface is a regular rotationally symmetric surface, the process of obtaining multiple holographic phase maps can be simplified, and multiple holographic phase maps corresponding to the rotationally symmetric surface can be accurately obtained.

[0116] Reference Figure 7 In some embodiments, step S104 may also include, but is not limited to, the following steps S701 to S702:

[0117] Step S701: When the target surface is a non-rotationally symmetric surface, divide the target light point into multiple subsets.

[0118] Step S702: Determine the holographic phase map corresponding to each sub-point set based on the phase of the target light point in each sub-point set.

[0119] In step S701 of some embodiments, when the target surface is a non-rotationally symmetric surface, referring to the above embodiments, after obtaining a large number of target light spots by the three-dimensional mesh division method, on the one hand, the number of light spot phases that the spatial light modulator can load at the same time is limited; on the other hand, in this embodiment, the target light spots obtained based on the three-dimensional mesh map of the target surface are uniformly distributed and exhibit a certain periodicity. This uniform and periodically distributed multifocal pattern will cause obvious moiré patterns to appear in the generated holographic phase map. The moiré patterns will cause secondary focusing of the processing beam, which will prevent the processing beam from forming an ideal multifocal spot and thus prevent the processing of an ideal target surface. Based on this, the obtained target light spots can be... The target light points are divided into multiple subsets. By grouping the target light points, the uniformity and periodicity of the target light point distribution are disrupted, eliminating moiré patterns in the holographic phase image. At the same time, the modulation capability upper limit of the spatial light modulator is met. It can be understood that each subset includes several target light points. The division method can be random division or clustering based on the coordinates of the target light points. Multiple target light points that are relatively close to each other are divided into the same subset. This avoids dividing multiple target light points that are relatively far apart into the same subset, which would result in the holographic phase image corresponding to the subset containing relatively dispersed phase information. This avoids the need to generate multi-focal light spots with relatively dispersed light field distribution, thereby optimizing the light field distribution corresponding to each holographic phase image. Each subset of points can contain the same number of target points. By uniformly dividing the target points into multiple subsets, the number of focal points in the multifocal spot formed by the processing beam each time is ensured to be the same. Thus, using a constant processing beam ensures that the optical power allocated to each focal point in the multifocal spot remains stable, and the time required for the processing beam to ablate each target point is also relatively fixed. Based on this, the holographic phase map modulated by the processing beam can be switched at a fixed frequency, simplifying the operation of switching the holographic phase map while ensuring ablation stability. In a feasible embodiment, each subset can contain 15 target points. Thus, each modulation of the processing beam will form a multifocal spot with 15 focal points. This avoids excessive focal points formed in a single modulation, preventing overlap and interference between the optical fields of each laser beam, ensuring accurate ablation at the target point's location, and avoiding excessive power dispersion of the processing beam, which could lead to insufficient optical power at each focal point and hinder rapid ablation of the substrate.

[0120] In step S702 of some embodiments, after dividing all target light points into multiple sub-sets, the holographic phase map corresponding to the sub-set can be determined based on the phase of all target light points in each sub-set. Specifically, the holographic phase map corresponding to the sub-set can be obtained by superimposing the phases of each target light point in the sub-set. The process of superimposing the phases of each target light point in the sub-set to determine the holographic phase map corresponding to the sub-set can refer to formula (1) in the above implementation. The phase of the target light point on the generatrix of the rotationally symmetric surface can be replaced with the phase of the target light point in the sub-set. It will not be elaborated here.

[0121] In this embodiment, when the target surface is a non-rotationally symmetric surface, after obtaining the coordinates of a large number of target light points based on the three-dimensional mesh division method, the target light points are divided into multiple sub-point sets. Based on the phase of the target light points in each sub-point set, the holographic phase map corresponding to the sub-point set is determined. Thus, the ablation rate is improved while ensuring the accuracy of the processing beam ablation of the substrate.

[0122] Reference Figure 8 In some embodiments, step S105 includes, but is not limited to, steps S801 to S803.

[0123] Step S801: When the target surface is a rotationally symmetric surface, a diffractive optical element is prepared based on the first holographic phase map;

[0124] Step S802: Modulate the light beam using diffractive optical elements to form a multifocal light spot distributed according to the generatrix of the target surface;

[0125] In step S803, during the process of modulating the light beam through the diffractive optical element, the diffractive optical element is rotated at a preset rotation speed to make the multifocal spot rotate and form a multifocal spot corresponding to the position of the generatrix of the target surface after rotation.

[0126] It is understood that a diffractive optical element (DOE) is a component with a special morphology and refractive index that can split a processing beam and finely control the wavefront phase distribution of the split beam, resulting in a specific wavefront phase and a specific optical field distribution. Combined with the focusing effect of a lens, it can modulate the processing beam into a specific multifocal spot. In this embodiment, when the target surface is a rotationally symmetric surface, a corresponding diffractive optical element can be fabricated based on a first holographic phase diagram. This diffractive optical element contains the generatrix phase information of the target surface and can modulate the wavefront phase of the processing beam to match the phase of each target point in the first holographic phase diagram, so that the modulated processing beam exhibits an optical field distribution corresponding to the generatrix of the target surface. It is understood that when fabricating the diffractive optical element, the point corresponding to the rotation center of the first holographic phase diagram can be used as the geometric center of the diffractive optical element.

[0127] In step S802 of some embodiments, after fabricating a corresponding diffractive optical element based on the first holographic phase diagram, the processing beam is modulated by the diffractive optical element, so that each segment of the modulated processing beam has a wavefront phase consistent with the phase of each target light point in the first holographic phase diagram. The processing beam has a light field distribution consistent with the generatrix shape of the target surface. Thus, when the processing beam passes through the diffractive optical element, it forms a multifocal spot distributed according to the generatrix shape of the target surface. Specifically, the diffractive optical element is placed at a corresponding position in the optical path of the processing beam, such as between the ultrafast laser and the objective lens that focuses the processing beam. In this way, when the processing beam passes through the diffractive optical element, the corresponding wavefront modulation is completed, and it has a wavefront phase corresponding to the first holographic phase diagram. After being focused by the objective lens, it can form a multifocal spot distributed according to the generatrix shape of the target surface.

[0128] In step S803 of some embodiments, during the modulation of the light beam by the diffractive optical element, the diffractive optical element is rotated at a preset rotational speed. It is understood that since the target surface is a rotationally symmetric surface, and the diffractive optical element is prepared based on a first holographic phase map corresponding to the generatrix of the surface, rotating the diffractive optical element is equivalent to modulating the processing light beam using the holographic phase map formed after rotating the first holographic phase map. This results in the processing light beam having a light field distribution consistent with the generatrix shape of the rotated target surface. This achieves the modulation of the processing light beam through multiple holographic phase maps sequentially, transforming the processing light beam into a multifocal spot corresponding to each holographic phase map. It is understood that since the process of rotating the diffractive optical element is dynamic and continuous, the processing light beam can be modulated into a continuous dynamic spatial multifocal spot by rotating the diffractive optical element, thereby forming a large number of continuous ablation points from the surface to the interior of the substrate. It is understood that the rotation center during the rotation of the diffractive optical element can be the geometric center of the diffractive optical element, i.e., the point in the diffractive optical element corresponding to the rotation center of the first holographic phase map. Specifically, diffractive optical elements can be mounted on a rotating stage, and the stage can rotate the diffractive optical elements at a set speed. At this time, the speed of switching the holographic phase map is no longer limited by the response time of the spatial light modulator. The rotation speed of the stage determines the speed of ablation of the substrate using multi-focal spot light, which can improve the efficiency of preparing rotationally symmetric three-dimensional microstructures, thereby efficiently preparing rotationally symmetric three-dimensional microstructures.

[0129] In this embodiment, when the target surface is a rotationally symmetric surface, a diffractive optical element containing the generatrix phase information of the target surface is prepared based on a first holographic phase map. This diffractive optical element is then used to modulate the processing beam, changing its wavefront phase to match the generatrix phase of the target surface. The modulated processing beam, after being focused by an objective lens, forms a multifocal spot with the same shape as the generatrix of the target surface. Simultaneously, during modulation, the diffractive optical element is rotated, causing the multifocal spot to rotate accordingly. This process sequentially modulates the processing beam into multifocal spots corresponding to each holographic phase map. In this embodiment, by preparing a diffractive optical element containing the generatrix phase information of the surface and controlling its rotation via a rotating stage, the effect of switching holographic phase maps is achieved. This eliminates the response time limitation of the spatial light modulator during holographic phase map switching. The rotational speed of the rotating stage directly determines the ablation speed of the substrate, effectively improving the efficiency of forming ablation points on the target surface within the substrate and enabling efficient fabrication of rotationally symmetric three-dimensional microstructures.

[0130] Reference Figure 9 This application also proposes a device for preparing three-dimensional glass microstructures, the device comprising:

[0131] Controller 101 is used to acquire the target three-dimensional structure to be prepared, determine the target surface based on the target three-dimensional structure, and determine the coordinates of multiple target light points based on the target surface. The controller is also used to determine the phase corresponding to each target light point based on the coordinates of the target light points and to determine multiple holographic phase maps based on the phases of all target light points.

[0132] The beam shaping module includes a modulation unit 102 and a focusing unit 103. The modulation unit 102 is used to modulate the processing beam according to multiple holographic phase diagrams, and the focusing unit 103 is used to focus the modulated processing beam to form a multifocal spot.

[0133] The stage 104 is used to support the substrate 105 and is positioned in the direction in which the focusing unit 103 emits the multi-focal light spot.

[0134] The corrosion module 106 is used to chemically corrode the ablated substrate 105 to connect the ablation points and form the target three-dimensional structure.

[0135] In this embodiment, the controller 101 can be an electronic device such as a personal PC. The controller 101 can acquire the target three-dimensional structure input by the user, analyze the target three-dimensional structure, extract its upper or lower surface as the target surface, further determine multiple points from the target surface as target light points, and determine the coordinates of each target light point based on the set spatial coordinate system. Then, calculate the corresponding phase based on the coordinates of the target light points. Thus, multiple holographic phase maps are generated based on the phases of all target light points.

[0136] In some embodiments, the modulation unit 102 may be a spatial light modulator connected to the controller 101, comprising a plurality of independent micropixels, each of which can independently adjust the wavefront phase of the laser. The controller 101 can directly transmit a holographic phase map to the spatial light modulator, causing it to adjust the state of each independent micropixel according to the loaded holographic phase map, so that the modulated laser has a holographic phase. Figure 1 The wavefront phase is straight. After loading multiple holographic phase maps onto the spatial light modulator, the holographic phase map used to modulate the processing beam can be switched at a rated frequency through the playback function of the spatial light modulator. In this way, the wavefront phase of the processing beam is modulated sequentially to match each holographic phase. Figure 1Furthermore, when the target surface is a rotationally symmetric surface, the modulation unit 102 can also be a diffractive optical element containing phase information of the generatrix of the target surface. Through this diffractive optical element, the wavefront phase of the passing processing beam can be modulated to match the phase information of the generatrix of the target surface, giving the processing beam a light field distribution with phase matching the generatrix of the target surface. Thus, after the modulated processing beam is focused by the focusing unit 103, it forms a multifocal spot with a shape consistent with the generatrix of the target surface. Furthermore, by rotating the diffractive optical element, the multifocal spot also rotates, presenting a shape corresponding to the generatrix rotated to the corresponding angle. At this point, the speed of switching the holographic phase map is directly determined by the speed of rotating the diffractive optical element, and is no longer limited by the response time of the spatial light modulator, effectively improving the efficiency of forming ablation points on the target surface in the substrate. In one embodiment, the focusing unit can be a 20x objective lens. In this embodiment, since only a limited number of target light spots on the target surface need to be ablated, compared with the traditional laser direct writing process that directly ablates the entire surface to prepare three-dimensional microstructures, the time required to ablate the substrate is greatly shortened, the difficulty of modulating the processing beam is greatly reduced, and the flexibility in processing three-dimensional glass microstructures is also greatly improved.

[0137] In some embodiments, the substrate 105 can be a glass substrate made of materials such as quartz glass or silicate glass. Utilizing its light-transmitting properties, multi-focal light spots can penetrate into the substrate, simultaneously processing multiple target light spots from the surface to the interior of the substrate 105. The stage 104 can be a three-axis precision displacement stage. The stage 104 is communicatively connected to the controller 101. When large-scale three-dimensional microstructures need to be fabricated, the controller 101 can move the substrate 105 placed on the upper surface of the stage 104. Specifically, the target surface can be divided into multiple sub-surfaces, and multiple holographic phase maps corresponding to each sub-surface can be calculated. This yields multiple sets of holographic phase maps corresponding to different sub-surfaces. After the spatial light modulator completes the ablation of the target light spot on one sub-surface based on the holographic phase map, the three-axis precision displacement stage is controlled to displace the substrate, ablating the target light spot in the next sub-surface. In this embodiment, the cooperation between the modulation unit and the stage can effectively increase the upper limit of the fabricated three-dimensional microstructure area.

[0138] In some embodiments, the etching module 106 can be a container filled with an etching solution. After the substrate is ablated and a large number of ablation points distributed according to the target surface are formed on the surface and inside of the substrate, the substrate is transferred to the etching module. Through the chemical etching and concentration stress of the etching solution, the substrate is etched. After the barriers between the ablation points are etched, the adjacent ablation points are connected to each other to form the target surface. The substrate is divided into two parts by the target surface, thereby obtaining the target three-dimensional structure. Under the action of chemical etching and concentration stress, the smoothness of the surface of the prepared three-dimensional microstructure can be effectively improved, realizing the processing of a truly three-dimensional microstructure with continuous changes. Based on this, the glass three-dimensional microstructure preparation device proposed in this embodiment can prepare high-quality glass three-dimensional microstructures.

[0139] In this embodiment, the controller 101 determines the target surface based on the target three-dimensional structure, and then determines multiple holographic phase maps required to generate multi-focal spots with the same shape as the target surface. The modulation unit 102 then modulates the processing beam sequentially based on the multiple holographic phase maps generated by the controller 101. The focusing unit 103 then focuses the modulated processing beam, sequentially forming multi-focal spots corresponding to each holographic phase map. These multi-focal spots ablate the substrate, creating multiple ablation points distributed according to the shape of the target surface from the surface to the interior of the substrate. Compared to existing laser direct writing methods, the ablation time is significantly reduced. After ablation of the substrate, the substrate is chemically etched using an etching module 106 containing an etching solution. Under the action of chemical etching and concentrated stress, the ablation points connect to form a smooth and continuously changing target surface, causing the portion surrounded by the target surface to detach from the substrate, thus obtaining a high-quality target three-dimensional microstructure. Based on the glass three-dimensional microstructure fabrication device proposed in this embodiment, high-quality glass three-dimensional microstructures can be efficiently fabricated using a combination of laser ablation and chemical etching.

[0140] Reference Figure 10In some embodiments, the processing beam can be a Gaussian linearly polarized pulsed laser emitted by an ultrafast laser 107, with a center wavelength of 1030 nm and a pulse width ranging from 3 picoseconds to 3000 femtoseconds. The ultrafast laser 107 and a control unit 101 are communicatively connected, allowing the control unit 101 to control the ultrafast laser 107 to emit or stop emitting the processing beam. It is understood that because the diameter of the Gaussian linearly polarized pulsed laser emitted by the ultrafast laser 107 is small, it is not conducive to subsequent beam splitting and modulation into a multifocal spot. Therefore, a beam-expanding and collimating module 108 can be used to expand the processing beam emitted by the ultrafast laser. Specifically, the beam-expanding and collimating module includes a first half-wave plate 1081, a concave lens 1082, and a convex lens 1083. The first half-wave plate 1081 can adjust the polarization state of the processing beam emitted by the ultrafast laser 107. Specifically, the first half-wave plate 1081 can filter out components in the processing beam other than those in the horizontal polarization direction, thus filtering the processing beam into a clean beam. Horizontally polarized light is used to avoid uneven processing on the substrate caused by scattering or reflection of non-horizontally polarized components in the processing beam. A concave lens 1082 can diverge the processing beam, increasing its diameter. Then, a convex lens 1083 focuses the beam, converging it into a parallel beam. Therefore, in this embodiment, the Gaussian linearly polarized pulse laser emitted by the ultrafast laser 107 is expanded into a wider processing beam by the beam-expanding and collimating module 108. This facilitates subsequent beam splitting and modulation into a multi-focal spot. In some embodiments, a Glan prism can be placed between the half-wave plate 1081 and the concave lens 1082. The Glan prism, in conjunction with the first half-wave plate 1081, can also adjust the energy of the processing beam.

[0141] Reference Figure 10 In some embodiments, at least one 4f transmission system 109 may be provided between the modulation unit 102 and the focusing unit 103. The 4f transmission system 109 consists of two convex lenses with the same focal length that are arranged opposite each other on the propagation optical path of the processing beam. The processing beam emitted from the modulation unit 102 can be compressed and transferred to the focusing unit 103 for focusing with high fidelity through the 4f transmission system.

[0142] Reference Figure 10In some embodiments, the glass three-dimensional microstructure fabrication apparatus further includes multiple beam splitters 111, an industrial camera 112, and an illumination source 113. The multiple beam splitters 111 are all disposed on the side of the focusing unit 102 facing away from the substrate 105. The multiple beam splitters 111 and the focusing unit 102 are in the same optical path. The illumination source 113 emits monochromatic illumination light in the direction of the beam splitters 111. After being reflected by the beam splitters, the monochromatic illumination light propagates in the direction of the focusing unit 102 to illuminate the substrate 105. The monochromatic illumination light propagates in the opposite direction along the incident path and is incident on the industrial camera 112 to form an image. The industrial camera 112 then transmits the captured image to the controller 101, thereby monitoring the processing.

[0143] Reference Figure 9 and Figure 10 In some embodiments, the glass three-dimensional microstructure fabrication apparatus is further provided with multiple reflectors 110 and beam splitters 111 to fold the propagation path of the processing beam, thereby reducing the volume of the glass three-dimensional microstructure fabrication apparatus.

[0144] This application also proposes a glass article, which is prepared by any of the glass three-dimensional microstructure preparation methods described in the above embodiments.

[0145] Reference Figure 11 , Figure 11 This is a schematic diagram of a cross-section of a hemisphere prepared by the glass three-dimensional microstructure preparation method proposed in the above embodiments. The theoretical radius of the hemisphere is 50 micrometers, and its generatrix equation on the XOZ plane can be expressed as:

[0146]

[0147] Points are selected based on the generatrix equation of the surface, and the phase of each target is determined based on the coordinates of each selected target light point, thereby obtaining the holographic phase map corresponding to the generatrix equation. The processing beam is modulated based on the phase information contained in the holographic phase map to generate a multi-focal spot. At the same time, the holographic phase map is rotated so that the multi-focal spot rotates one revolution. It can be understood that in order to ensure that a continuous hemispherical surface can be formed after the etching and ablation points, the distance between two adjacent ablation points should be kept small. Based on this, the step angle can be determined according to the radius of the hemisphere. For example, in this embodiment, the radius of the hemisphere is 50 micrometers, and its theoretical half-circumference is 50π. In order to ensure that the distance between the two sets of target light points obtained before and after rotating the holographic phase map is less than 3 micrometers in the horizontal direction, the arc length corresponding to the step angle in the circle with a half-circumference of 50π should be less than 3 micrometers. Based on the arc length formula, the range of values ​​for the step angle under the radius of the hemisphere can be obtained. Numerous ablation points distributed along a hemispherical surface are etched onto a glass substrate. Finally, the glass substrate is etched to connect these ablation points, forming a hemispherical surface that extends from the substrate surface to its interior. This surface divides the glass substrate into two parts, resulting in a cross-section as shown below. Figure 11 The hemisphere shown has an actual radius of 50.2 micrometers, with an error controlled within 0.2 micrometers compared to its theoretical radius. It should be noted that... Figure 11 The coordinate system in this example is only used to measure the actual shape parameters of the hemisphere prepared by the method proposed in this embodiment, and is not used as the coordinate system when calculating the generatrix equation of the hemisphere surface.

[0148] Reference Figure 12 , Figure 12 This is a schematic diagram of a cross-section of a cone prepared by the glass three-dimensional microstructure preparation method proposed in the above embodiments. The theoretical depth of the cone is 200 micrometers, and the theoretical radius of the arc at the base of the cone is 80 micrometers. The equation of the generatrix of the cone on the XOZ plane can be expressed as:

[0149]

[0150] Points are selected based on the generatrix equation of the surface, and the phase of each target is determined based on the coordinates of each selected target light point, thereby obtaining the holographic phase map corresponding to the generatrix equation. The processing beam is modulated based on the phase information contained in the holographic phase map to generate a multi-focus light spot. At the same time, the holographic phase map is rotated so that the multi-focus light spot rotates one revolution. It can be understood that in order to ensure that a continuous conical surface can be formed after the etching and ablation points, the distance between two adjacent ablation points should be kept small. Based on this, the step angle can be determined according to the radius of the arc of the cone's base. For example, in this embodiment, the radius of the cone's base is 80 micrometers, and its theoretical half-circumference is 80π. In order to ensure that the distance between the two sets of target light points obtained before and after rotating the holographic phase map is less than 3 micrometers in the horizontal direction, the arc length corresponding to the step angle in the circle with a half-circumference of 80π should be less than 3 micrometers. Based on the arc length formula, the value range of the step angle under this radius can be obtained. Numerous ablation points distributed along a conical surface are etched onto a glass substrate. Finally, the glass substrate is etched to connect these ablation points, forming a conical surface that extends from the substrate surface to its interior. This conical surface divides the glass substrate into two parts, resulting in a cross-section as shown below. Figure 12 The cone shown has an actual depth of 202.9 micrometers and a base diameter of 160.3 micrometers. Compared to the theoretical diameter and theoretical depth, the error in the depth direction is controlled within 3 micrometers, and the error in the horizontal direction is controlled within 1 micrometer. It should be noted that... Figure 12 The coordinate system in this example is only used to measure the actual shape parameters of the cone prepared by the method proposed in this embodiment, and is not used as the coordinate system when calculating the generatrix equation of the conical surface.

[0151] Figure 13This is a schematic diagram of a cross-section of a square pyramid prepared by the glass three-dimensional microstructure preparation method proposed in the above embodiments. The theoretical depth of the square pyramid is 200 micrometers, and the base of the pyramid is a square with a side length of 160 micrometers. The lower surface of the square pyramid is taken as the target surface. At this time, the target surface is a non-rotationally symmetric surface composed of four triangles. By converting this surface into a three-dimensional mesh, the mesh points in the three-dimensional mesh are taken as target light points, thereby obtaining the coordinates of a large number of target light points. It can be understood that in order to form a continuous target surface after the ablation points formed at the target light points are subsequently connected by etching, the horizontal distance between two adjacent target light points on the upper surface of the glass substrate should be controlled to be within 3 micrometers, and the distance in the direction perpendicular to the upper surface of the glass substrate should be within 8 micrometers. Then, these target light points are grouped, specifically, each group can contain 15 target light points. Subsequently, a corresponding holographic phase map is generated based on the phase of each set of target light points. The processing beam is modulated using the holographic phase map corresponding to each set of target light points to form a multi-focal spot. Finally, a large number of ablation points are formed on the glass substrate according to the curved surface of a square pyramid. Under the corrosion of the chemical solution, the ablation points connect to form a curved surface that continues from the surface to the interior of the glass substrate, separating the glass substrate into two parts. The part that detaches from the glass substrate is the square pyramid. (Refer to...) Figure 13 The actual depth of the square pyramid prepared by the glass three-dimensional microstructure preparation method proposed in this embodiment is 202.7 micrometers, and the side length of the square base is 160.1 micrometers. Compared with its theoretical shape, the error in the depth direction is controlled within 3 micrometers, and the error in the horizontal direction is controlled within 0.1 micrometers.

[0152] Figure 14This is a schematic diagram of a cross-section of an elliptical hemisphere prepared by the glass three-dimensional microstructure preparation method proposed in the above embodiments. The theoretical depth of the elliptical hemisphere is 85 micrometers, the theoretical width of its major axis is 280 micrometers, and the theoretical width of its minor axis is 210 micrometers. The lower surface of this elliptical hemisphere is used as the target surface, which is a non-rotationally symmetric surface. Based on this, the lower surface of the elliptical hemisphere is transformed into a three-dimensional mesh map, and the mesh points of this three-dimensional mesh map are taken as target light points, obtaining the coordinates of a large number of target light points. It is understood that, in order to ensure that the ablation points formed at the target light points can form a continuous target surface after subsequent etching connections, the horizontal distance between two adjacent target light points on the upper surface of the glass substrate should be controlled to be within 3 micrometers, and the distance in the direction perpendicular to the upper surface of the glass substrate should be within 8 micrometers. Then, these target light points are grouped; specifically, each group can contain 15 target light points. Subsequently, a corresponding holographic phase map is generated based on the phase of each set of target light points. The processing beam is modulated using the holographic phase map corresponding to each set of target light points to form a multi-focal spot. Finally, a large number of ablation points are formed on the glass substrate according to the surface of an elliptical hemisphere. Under the corrosion of the chemical solution, the ablation points connect to form a curved surface that continues from the surface to the interior of the glass substrate, separating the glass substrate into two parts. The part that detaches from the substrate is the elliptical hemisphere. (Refer to...) Figure 14 The elliptical hemisphere prepared by the method of this embodiment has an actual major axis length of 280.7 micrometers, a minor axis length of 210.6 micrometers, and an actual depth of 84.5 micrometers. Compared with its theoretical shape, the error in the depth direction is controlled within 0.5 micrometers, and the error in the horizontal direction is controlled within 1 micrometer.

[0153] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual order of execution may change depending on the specific circumstances.

[0154] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0155] The terms “comprising” and “having”, and any variations thereof, in the specification and accompanying drawings of this application are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or that are inherent to such process, method, product, or apparatus.

[0156] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0157] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0158] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for preparing a three-dimensional glass microstructure, characterized in that, The method includes: Step S1: Obtain the target three-dimensional structure to be prepared, and determine the target surface based on the target three-dimensional structure. The target surface is the upper or lower surface of the target three-dimensional structure. Step S2: Determine the coordinates of multiple target light points based on the target surface, wherein each target light point is a point on the target surface; perform clustering based on the coordinates of the target light points, dividing multiple target light points with relatively short distances into the same subset; determine the phase corresponding to each target light point based on the coordinates of the target light points; determine multiple holographic phase maps corresponding to the subsets based on the phases of all target light points; the target surface in step S2 includes rotationally symmetric surfaces and non-rotationally symmetric surfaces; When the target surface is a rotationally symmetric surface, the generatrix equation of the rotationally symmetric surface is obtained; the coordinates of each target light point are determined according to the generatrix equation; wherein, the axis of the processing beam is the z-direction, the maximum distance between two adjacent target light points in the z-direction is less than 8 micrometers, and the maximum distance in the horizontal direction is less than 3 micrometers; a first holographic phase map is determined according to the phase corresponding to each target light point on the generatrix of the target surface; the first holographic phase map is rotated according to a preset step angle to obtain multiple holographic phase maps; When the target surface is a non-rotationally symmetric surface, a corresponding three-dimensional mesh is determined based on the target surface; the coordinates of each target light point are determined based on the coordinates of each mesh point in the three-dimensional mesh; the phase corresponding to each target light point is determined based on the coordinates of the target light points; the target light points are divided into multiple subsets; and a holographic phase map corresponding to each subset is determined based on the phase of the target light points in each subset. Step S3: The processing beam is modulated sequentially by the multiple holographic phase maps to modulate the processing beam into multifocal spots corresponding to different sub-point sets. Step S4: The substrate is ablated by the multi-focus spot to form ablation points distributed according to the target surface at the position of each target spot inside the substrate; Step S5: Chemically etch the substrate to connect the ablation points and form the target three-dimensional structure.

2. The method according to claim 1, characterized in that, The process of modulating and processing the beam using the multiple holographic phase maps sequentially includes: When the target surface is a rotationally symmetric surface, a diffractive optical element is fabricated based on the first holographic phase map; The light beam is modulated by the diffractive optical element to form a multifocal light spot distributed according to the generatrix of the target surface; During the process of modulating the light beam through the diffractive optical element, the diffractive optical element is rotated at a preset rotation speed to make the multifocal spot rotate, forming the multifocal spot corresponding to the position of the generatrix of the target surface after rotation.

3. The method according to claim 1, characterized in that, Each of the sub-point sets includes no more than 15 of the target light spots, so that when the holographic phase map corresponding to each of the sub-point sets modulates the processing beam, a three-dimensional multifocal spot including no more than 15 focal points is formed.

4. The method according to claim 1, characterized in that, The process of modulating and processing the beam using the multiple holographic phase maps sequentially includes: Multiple holographic phase maps are loaded into a spatial light modulator, and the holographic phase maps are switched according to frequency in the spatial light modulator to modulate the wavefront phase of the beam to be consistent with the phase information contained in the corresponding holographic phase map, thereby forming a multifocal spot consistent with the phase information of each holographic phase map.

5. The method according to claim 1, characterized in that, The step of determining the phase corresponding to each target light point based on the coordinates of the target light points includes: The deflection and focusing depth of the target light spot are determined based on its coordinates. The first phase of the blazed grating required to deflect the processing beam to the target spot position is determined based on the deflection amount. The second phase of the lens required to focus the processing beam at the target spot is determined based on the focusing depth. The phase corresponding to the target light spot is determined based on the first phase and the second phase.

6. The method according to claim 1, characterized in that, Before clustering based on the coordinates of the target light point, the method further includes: The coordinates of the target light spot are corrected based on the refractive index of the substrate.

7. A glass three-dimensional microstructure fabrication apparatus, used to implement the glass three-dimensional microstructure fabrication method according to any one of claims 1 to 6, characterized in that, The device includes: The controller is used to acquire the target three-dimensional structure to be prepared, determine the target surface based on the target three-dimensional structure, and determine the coordinates of multiple target light points based on the target surface; perform clustering based on the coordinates of the target light points, and divide multiple target light points with relatively short distances into the same subset of points; the controller is also used to determine the phase corresponding to each target light point based on the coordinates of the target light points, and determine multiple holographic phase maps corresponding to the subset of points based on the phases of all the target light points. The beam shaping module includes a modulation unit and a focusing unit. The modulation unit is used to modulate the processing beam sequentially through the multiple holographic phase maps. The focusing unit is used to focus the modulated processing beam to form a multi-focus spot corresponding to different sub-point sets. The multi-focus spot ablates the substrate to form ablation points distributed according to the target surface at the position of each target light point inside the substrate. A stage for supporting a substrate is provided, and the stage is positioned in the direction in which the focusing unit emits the multifocal light spot. The etching module is used to chemically etch the ablated substrate to connect the ablation points and form the target three-dimensional structure.

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