CN115401313A - Two-photon automatic processing method, system and equipment for non-flat substrate - Google Patents

Abstract

The invention relates to a two-photon automatic processing method, a system and equipment for a non-flat substrate. The processing method comprises the following steps: s1: adjusting the horizontal position of the substrate to enable the horizontal position of the laser focus to be located in the initial processing area of the substrate; s2: focusing laser, and performing laser processing at an initial processing position after focusing; s3: moving the substrate to the next processing point, focusing at the processing point, and performing laser processing at the processing point after focusing is completed; s4: and repeating the step S3 until all the processing points are processed, and developing the processed micro-nano structure to obtain the finished micro-nano structure. According to the invention, through carrying out automatic focusing on each processing point, the problems of complicated manual focusing operation, time consumption and larger error in the processing process of using laser on a non-flat substrate are solved.

Description

A two-photon automatic processing method, system and equipment for non-flat substrates

technical field

The invention relates to the technical field of laser processing, in particular to a two-photon automatic processing method for non-flat substrates, a two-photon automatic processing system for non-flat substrates, a two-photon automatic processing system for non-flat substrates Processing Equipment.

Background technique

Femtosecond laser micro-nanofabrication is an emerging method for forming nanostructures. It can be regarded as a special kind of 3D printing, that is, stereolithography. During the focusing process of femtosecond laser two-photon direct writing processing, the staff needs to find the interface between the two-photon material and the substrate as the processing reference plane. By controlling the three-dimensional motion table to control the relative position of the two-photon processing material on the substrate and the laser focus, when a suitable processing reference plane is found, the femtosecond laser two-photon direct processing is performed on the two-photon material.

When the laser focus deviates from the processing reference plane, there will be two situations: a) When most of the laser focus is in the base material, the processed structure is incomplete compared with the designed structure, and part of the processed structure will be lost after development. b) When the focus is completely on the polymer material, the processed structure will not be connected to the substrate, and the processed structure will be washed away after development, resulting in a complete loss of the structure.

In the process of processing, the non-flat substrate can be roughly divided into three situations: 1. Flexible substrate (as shown in Figure 1.a). 2. Patterned substrate (as shown in Figure 1.b). 3. Tilt the base (as shown in Figure 1.c).

Use femtosecond lasers to process micro-nano structures on flexible substrate materials (as shown in Figure 2.a). Due to irregular changes in the topography of the substrate surface, after the initial focus is completed, the micro-nano structure of subsequent processing is lost or completely lost (as shown in Figure 2.b). At present, the staff solves this problem by refocusing manually after processing a structure and then continuing to process the next structure (as shown in Figure 2.c). However, this method is cumbersome to operate, and the manual focus is to determine the axial position of the focus by visually observing the spot size when the laser interacts with the material to be processed. There are large random errors in visual observation, which affect the processing quality.

Contents of the invention

Based on this, it is necessary to address the problems of complicated, time-consuming manual focusing operations and large errors in the existing process of using lasers to process non-flat substrates. A two-photon automatic processing method, system and equipment for non-flat substrates are proposed.

The present invention is achieved through the following technical solutions: a two-photon automatic processing method for non-flat substrates, which includes the following steps:

S1: Adjust the horizontal position of the substrate so that the horizontal position of the laser focus is within the initial processing area of the substrate. The initial processing area means that when any point in this area is used as the initial processing point, the horizontal area where the design structure is located is located on the substrate.

S2: focusing the laser so that the substrate is located at an ideal initial processing position, and performing laser processing at the initial processing position according to a corresponding processing strategy. Among them, the method of focusing is as follows:

S21: Taking the fluorescent polymer as a framing object, and collecting the light spot image of the fluorescent polymer scattering fluorescence in real time.

S22: adjust the height of the base, and calculate the maximum equivalent diameter of the light spot as a reference value when the equivalent diameter of the light spot in the light spot image reaches a maximum value.

S23: Calculate the ideal value of the equivalent diameter of the light spot according to the physical properties of the fluorescent polymer and the reference value.

S24: Adjust the height of the base until the equivalent diameter of the spot in the spot image is equal to an ideal value.

S3: Control the substrate to move to the next processing point according to the preset moving path, judge whether the equivalent diameter of the spot in the spot image is equal to the ideal value, and make the following decisions:

(1) Yes, laser processing is performed directly at this position.

(2) Otherwise, focus at the processing point, and perform laser processing at the processing point after focusing.

S4: Determine whether the processing is completed, if not, repeat S3 until the processing is completed. If the processing is completed, the processed micro-nano structure is developed to obtain a finished micro-nano structure.

The invention solves the problem of complicated manual focusing operation, time-consuming and large errors during the process of using femtosecond laser to process non-flat substrates by automatically focusing on each processing point.

In one of the embodiments, the initial processing area is calculated according to the horizontal area covered by the substrate and the horizontal area covered by the scanning strategy. The specific method is as follows:

a. Map the outline p _j of the substrate, the outline p _l of the laser focus, the horizontal area p _p covered by the processing strategy, and the horizontal area p _s covered by the scanning strategy on the same plane. Set p _l and p _p concentrically, and move within p _j along the path tangent to p _p and p _j for one week. Remove the area surrounded by p _l and p _j from p _j to get the intermediate shape p _m .

b. Scale p _m until the graph after scaling is just circumscribed on p _s . Suppose p _m is an n-gon, and the figure circumscribed on p _s is p _ms , then fit the n corners of p _ms to each corresponding corner of p _m in turn. Every time you fit, make extension lines for the other n-2 sides that are not adjacent to the corner you fit. Multiple extension lines divide p _s into multiple sub-areas, and the sub-area containing each corner of p _m is used as the initial processing area.

In one of the embodiments, the method for judging that the laser focus is located in the initial processing area is as follows:

S11: Taking the substrate as a viewfinder object, collecting a substrate image including a laser focal point.

S12: Preprocessing the substrate image, retaining the outer contour of the substrate and the outer contour of the laser focus.

S13: Adding the contour line of the initial processing area to the outer contour of the base.

S14: Observe whether the outer contour of the laser focus is completely within the initial processing area, and if so, confirm that the laser focus is within the initial processing area. Otherwise move the substrate until the outer contour of the laser focus is completely within the initial processing area.

In one of the embodiments, the method for obtaining the benchmark value is as follows:

S221: Observe whether there is a light spot in the initial light spot image, and make the following decision: if there is no light spot, lift and lower the base until the light spot appears in the light spot image. If there is a light spot, control the substrate to move up or down, and observe the size change of the light spot.

S222: Determine whether the size of the light spot increases, and make the following decision: if the light spot gradually becomes smaller, reversely move the substrate to increase the size of the light spot in the light spot image. If the light spot becomes larger gradually, the control substrate continues to move in the original direction until the size of the light spot remains unchanged. If the spot remains unchanged, the equivalent diameter of the spot reaches the maximum, and the minimum circumscribed circle of the spot is obtained, then the diameter of the minimum circumscribed circle is the reference value.

In one embodiment, the movement of the substrate is three-dimensional movement, with the initial processing point as the origin, the vertical direction as the Z axis, any horizontal direction as the X axis, and the other horizontal direction perpendicular to the X axis as the Y axis. Then the movement path only includes the movement of the substrate on the X-axis and the Y-axis, and the focusing process only includes the movement of the substrate on the Z-axis.

The present invention also provides a two-photon automatic processing system for non-flat substrates, which includes:

The imaging module is used for real-time acquisition of light spot images containing fluorescent polymers and their scattered fluorescence.

The image processing module is used for preprocessing the spot image and calculating the equivalent diameter of the spot in the spot image. The preprocessing of spot image includes normalization processing and filtering processing. Normalization processing can convert each spot image into the same form, maintain the same standard in the process of multiple processing, and improve the processing accuracy. Filtering can suppress the noise of the image and improve the accuracy of image processing under the premise of retaining the details of the image.

The decision-making module is used for: 1. judging whether the equivalent diameter of the light spot is the maximum value, and if so, recording the maximum value of the equivalent diameter as a reference value. 2. Determine whether the equivalent diameter of the light spot is an ideal value, and if so, confirm that the focus is completed.

The displacement control module is used for: Ⅰ. Outputting a displacement signal according to a preset movement path, and then controlling the movement table to drive the base to move horizontally. Ⅱ. Output the displacement signal according to the preset processing strategy, and then control the motion table to drive the three-dimensional movement of the base. Ⅲ. When focusing, output the lifting signal to control the motion table to drive the base to rise and fall.

The invention also provides a two-photon automatic processing equipment for non-flat substrates, which includes a laser, a moving table, an optical path adjuster, an objective lens, an imaging device and a controller.

Lasers are used to emit laser light. The substrate is used to carry the fluorescent polymer, so that the fluorescent polymer is located on the path of the laser light, and the fluorescent polymer produces a fluorescent effect when irradiated by the laser light. The motion table is fixedly connected with the base, and is used to drive the base to move. The base can be fixedly connected to the moving table by means of magnetic attraction to ensure that the base does not shift when the moving table drives the base to move.

The optical path regulator is arranged on the emission path of the laser, and is used to adjust the intensity and direction of the laser, so that the laser can be used for processing or focusing respectively. The objective lens is arranged on the laser output path of the optical path adjuster, and is used for focusing the laser light. The imaging device is arranged on the fluorescence path scattered by the fluorescent polymer, and is used for real-time collection of light spot images including the fluorescent polymer and its scattered fluorescence. The imaging device is also used to transmit the collected light spot images to the controller.

The controller is used for: 1. Controlling the moving table to adjust the horizontal position of the substrate so that the horizontal position of the laser focus is located in the initial processing area of the substrate. 2. Focus the laser emitted by the laser so that the substrate is located at the ideal initial processing position, and perform laser processing at the initial processing position according to the corresponding processing strategy. 3. Control the motion table to drive the substrate to move according to the preset moving path, and then complete the corresponding laser processing at each processing point. 4. Judging whether the equivalent diameter of the spot in the spot image is equal to the ideal value, if so, perform laser processing directly at this position. Otherwise, focus at the processing point, and perform laser processing at the processing point after focusing.

In one of the embodiments, the optical path adjuster includes an optical gate, a pre-adjuster and a beam splitter. The pre-regulator is arranged on the laser emission path of the laser, and is used for adjusting the energy and phase of the laser. The light gate is arranged between the laser and the pre-regulator, and is used to control the on-off of the laser. The beam splitter is arranged on the laser output path of the pre-regulator, and is used to reflect the processed laser and transmit the imaging light. The optical path regulator is used to adjust the energy and phase of the laser, so that the laser can be used for processing and focusing respectively. At the same time, the laser is divided into the transmitted beam and the reflected beam, so as to complete the laser focusing and spot image acquisition synchronously, and improve the efficiency of laser focusing. efficiency and precision

In one embodiment, the pre-adjuster includes a Glan-Taylor prism, a half-wave plate, a beam expander, a reflector and an attenuation plate arranged in sequence along the laser emission path. Glan Taylor prisms are used to control the energy of laser beams. Half-wave plates are used to adjust the phase of the laser beam. Beam expanders are used to increase the diameter of a laser beam. The reflector is used to adjust the emission direction of the laser beam. Attenuators are used to adjust the energy of the laser beam.

In one embodiment, the laser is a femtosecond laser, the imaging device is a CCD camera, and the moving stage is a three-dimensional micro-nano moving stage.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention solves the problem of complicated, time-consuming manual focusing operations and large errors during the processing of non-flat substrates using femtosecond lasers by automatically focusing on each processing point.

2. The present invention adopts the method of fluorescent focusing, by converting the focusing of the laser focus into fluorescent image recognition, and confirming whether the focusing is completed according to the equivalent diameter of the spot, effectively improving the focusing efficiency and focusing accuracy.

3. In the present invention, by presetting the initial processing area, the micro-nano structure obtained by laser processing can be just placed on the substrate, so as to avoid partial loss of the micro-nano structure and improve processing efficiency.

4. Using a three-dimensional micro-nano motion table to drive the substrate to move, it can drive the substrate to move freely within the three-dimensional range, so that the laser processing equipment can complete complex three-dimensional structure processing, and at the same time improve the focusing accuracy and focusing efficiency of the processing equipment.

5. Use the optical path regulator to adjust the energy and phase of the laser, so that the laser can be used for processing and focusing respectively. At the same time, the laser is divided into the transmitted beam and the reflected beam, so that the laser focusing and spot image acquisition can be completed synchronously, and the laser can be improved. Focus efficiency and precision.

Description of drawings

Fig. 1 is non-flat base classification diagram in the background technology of the present invention;

Fig. 2 is a three-dimensional micro-nano structure distortion diagram in the background technology of the present invention;

3 is a flow chart of the two-photon automatic processing method for non-flat substrates according to Embodiment 1 of the present invention;

Fig. 4 is a schematic diagram of obtaining the intermediate profile p _m of the initial processing area in Fig. 3;

Fig. 5 is a schematic diagram of the angle fit of the ideal initial processing area in Fig. 3;

Fig. 6 is a schematic diagram of the position of the ideal initial processing area in Fig. 3;

Fig. 7 is a schematic diagram of angle fitting of the actual initial processing area in Fig. 3;

Fig. 8 is a schematic diagram of the position of the actual initial processing area in Fig. 3;

9 is a schematic diagram of the relationship between the relative position of the laser focus in FIG. 3 and the size change of the fluorescent spot and the final processing result;

Figure 10 is a schematic diagram of the size of the fluorescent spot when the laser focus in Figure 3 is located at different positions;

Fig. 11 is a schematic diagram of the moving direction of the substrate in Fig. 3;

12 is a schematic diagram of the laser path of the two-photon automatic processing equipment for non-flat substrates using the two-photon automatic processing method for non-flat substrates in FIG. 3;

Fig. 13 is the fluorescent color and the microcolumn array diagram when the laser focus is at different heights relative to the substrate surface;

Fig. 14 is the fluorescent color and microcolumn array diagram realized after using autofocus;

Fig. 15 is an experimental comparison diagram of processing micro-nano structures at different positions on a patterned substrate.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that when a component is said to be "mounted on" another component, it can be directly on the other component or there can also be an intervening component. When a component is said to be "set on" another component, it may be set directly on the other component or there may be an intervening component at the same time. When a component is said to be "fixed" to another component, it may be directly fixed to the other component or there may be an intervening component at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Example 1

Please refer to FIG. 3 , which is a flow chart of the two-photon automatic processing method for non-flat substrates in this embodiment. The two-photon automatic processing method for non-flat substrates includes the following steps:

S1: Adjust the horizontal position of the substrate so that the horizontal position of the laser focus is within the initial processing area of the substrate. The initial processing area means that when any point in this area is used as the initial processing point, the horizontal area where the design structure is located is located on the substrate.

In this embodiment, laser two-photon processing is based on a designed structure, and the fluorescent polymer to be processed is processed on the substrate into a micro-nano structure that matches the size of the designed structure. In order to ensure that the laser-processed micro-nano structure is completely located on the substrate, it is necessary to position the initial processing point of the laser process. In this embodiment, the method of presetting the initial processing area on the substrate is used, the laser focus is positioned in the initial processing area, and then the laser two-photon processing is performed according to the initial processing point and the placement direction of the substrate, so that the processed micro-nano structure is completely on the surface of the substrate.

Please combine Figure 4 to Figure 8, Figure 4 is a schematic diagram of the intermediate shape p _m of the initial processing area in Figure 3; Figure 5 is a schematic diagram of the angle fit of the ideal initial processing area in Figure 3; Figure 6 is the ideal in Figure 3 Figure 7 is a schematic diagram of the angle fitting of the actual initial processing area in Figure 3; Figure 8 is a schematic diagram of the position of the actual initial processing area in Figure 3. Among them, the initial processing area is calculated according to the horizontal area covered by the substrate and the horizontal area covered by the scanning strategy. The specific method is as follows:

a. Map the outline p _j of the substrate, the outline p _l of the laser focus, the horizontal area p _p covered by the processing strategy, and the horizontal area p _s covered by the scanning strategy on the same plane. Set p _l and p _p concentrically, and move within p _j along the path tangent to p _p and p _j for one week. Remove the area surrounded by p _l and p _j from p _j to get the intermediate shape p _m .

In this embodiment, the substrate is in the shape of a sheet, and the outer profile of the substrate is denoted as p _j . The laser focus is an ellipsoid, and the laser focus forms an elliptical projection on the horizontal plane, and the outer contour of the elliptical projection is marked as p _l . The projection on the horizontal plane of the micro-nano structure processed at each processing point is denoted as p _p . In the scanning strategy, the polygon formed by all processing points is recorded as p _m . Taking the center of the laser focus as the processing center, if the processed micro-nano structure falls completely on the substrate, p _p must not exceed p _j , so the initial processing area cannot be adjacent to the outer contour of the substrate.

b. Scale p _m until the graph after scaling is just circumscribed on p _s . Suppose p _m is an n-gon, and the figure circumscribed on p _s is p _ms , then fit the n corners of p _ms to each corresponding corner of p _m in turn. Every time you fit, make extension lines for the other n-2 sides that are not adjacent to the corner you fit. Multiple extension lines divide p _s into multiple sub-areas. Take the subregion of each corner containing p _m as the initial processing region.

Taking a rectangular base as an example, let the length of the base be l _j , the width d _j , the major axis of the elliptical projection of the laser focus be l _l , and the minor axis be d _l . If the horizontal area p _p covered by the processing strategy and the horizontal area p _s covered by the scanning strategy are also rectangular, and the length of p _s is l _s and the width is d _s , the length of p _p is l _p and the width is d _p . Then the length and width of p _m are respectively l _m =(l _j -l _p +l _l ) and d _m =(d _j -d _p +d _l ). The theoretical initial processing area includes four rectangles at the four corners, and the length and width of each rectangle are (lm -l _s ) and ( _{d m -d s} ) respectively. The initial processing area actually selected in this embodiment is that the field width of each rectangle is [1-Max(l _s /l _m -d _s /d _m )]×l _m and [1-Max(l _s /l _m -d _s /d _m )]×d _m .

It can be seen that the theoretical initial processing area is larger than the actual initial processing area. When p _j , p _p and p _s are all standard rectangles, the steps to calculate the theoretical initial processing area are not only simpler, but also larger. However, when p _j , p _p and p _s are all non-standard rectangles, since the outer contours of p _m and p _s are different, it is difficult to directly fit the corners of p _ms and p _m . By scaling p _m , the p _ms formed by scaling is circumscribed on p _s , which greatly reduces the operation steps and improves the selection efficiency of the initial processing area.

Please combine Figure 9 and Figure 10, the method of judging that the laser focus is located in the initial processing area is as follows:

S11: Taking the substrate as a viewfinder object, collecting a substrate image including a laser focal point. Since the size of the substrate and the laser focus are both on the order of microns, it is difficult to directly observe the position of the laser focus relative to the substrate with the naked eye. Therefore, by imaging the substrate, observe the position of the laser focus relative to the substrate image to confirm whether the laser focus is Located in the initial processing area.

S12: Preprocessing the substrate image, retaining the outer contour of the substrate and the outer contour of the laser focus. The preprocessing of the base image includes normalization and filtering. Normalization processing can convert the image into the same form, maintain the same standard in the process of multiple processing, and improve the processing accuracy. Filtering can suppress the noise of the image and improve the accuracy of image processing under the premise of retaining the details of the image. The outer contours of the substrate and laser focus can be obtained by image recognition models. Converting image processing into mathematical graphics processing can simplify the processing process and improve processing accuracy.

S13: Adding the contour line of the initial processing area to the outer contour of the base. The initial processing area can be calculated according to the shape p _j of the substrate, the shape p _l of the laser focus, the horizontal area p _p covered by the processing strategy, and the horizontal area p _s covered by the scanning strategy, and then the initial processing area is added to the substrate image.

S14: Observe whether the outer contour of the laser focus is completely within the initial processing area, and if so, confirm that the laser focus is within the initial processing area. Otherwise move the substrate until the outer contour of the laser focus is completely within the initial processing area.

Observing whether the laser focus is in the initial processing area through image processing can effectively improve the positioning accuracy of the initial processing point, and avoid the loss of part of the structure caused by the processed micro-nano structure exceeding the surface of the substrate.

S2: focusing the laser so that the substrate is located at an ideal initial processing position, and performing laser processing at the initial processing position according to a corresponding processing strategy.

Among them, the method of focusing is as follows:

S21: Taking the fluorescent polymer as a framing object, and collecting the light spot image of the fluorescent polymer scattering fluorescence in real time. The fluorescent polymer produces fluorescence effect under laser irradiation, and the substrate is photographed in real time by an imaging device such as a camera. After video processing and image processing, the substrate image including fluorescent spots can be extracted.

S22: adjust the height of the base, and calculate the maximum equivalent diameter of the light spot as a reference value when the equivalent diameter of the light spot in the light spot image reaches a maximum value.

Here's how to get the baseline value:

S221: Observe whether there is a light spot in the initial light spot image, and make the following decision: if there is no light spot, lift and lower the base until the light spot appears in the light spot image. If there is a light spot, control the substrate to move up or down, and observe the size change of the light spot.

Please refer to FIG. 9 , which is a schematic diagram of the relative position of the laser focus and the size change of the fluorescent spot in FIG. 3 . It can be seen that when the laser focus is completely in the substrate, the fluorescent polymer does not produce a fluorescent effect, so there is no fluorescent spot in the spot image. When the laser focus moves from the substrate to the fluorescent polymer until it touches the fluorescent polymer, the fluorescent polymer produces a fluorescent effect, and fluorescent spots begin to appear in the spot image. When the laser focus continues to move into the fluorescent polymer until the center of the laser focus is just at the interface between the substrate and the fluorescent polymer, the fluorescence effect produced by the fluorescent polymer reaches the maximum, and the equivalent diameter of the spot in the spot image also reaches the maximum. The laser focus continues to move until it is completely in the fluorescent polymer, and the size of the spot in the spot image does not change.

S222: Determine whether the size of the light spot increases, and make the following decision: if the light spot gradually becomes smaller, reversely move the substrate to increase the size of the light spot in the light spot image. If the light spot becomes larger gradually, the control substrate continues to move in the original direction until the size of the light spot remains unchanged. If the spot remains unchanged, the equivalent diameter of the spot reaches the maximum, and the minimum circumscribed circle of the spot is obtained, then the diameter of the minimum circumscribed circle is the reference value.

According to the change of the fluorescence effect produced by the light spot in the substrate and the fluorescent polymer, the laser focus can be moved to just the interface between the substrate and the fluorescent polymer by moving the substrate. After the spot size does not change any more, take a spot image at random, and the smallest circle on the spot is the equivalent diameter of the spot. In this embodiment, the maximum equivalent diameter of the light spot is recorded as the reference value.

S23: Calculate the ideal value of the equivalent diameter of the light spot according to the physical properties of the fluorescent polymer and the reference value.

Please refer to FIG. 10 , which is a schematic diagram of the size of the fluorescent spot when the laser focus in FIG. 3 is located at different positions. Among them, Figure 10.a is a schematic diagram of the spot image when the laser focus is located in the substrate; Figure 10.b is a schematic diagram of the spot image when the laser focus begins to contact the fluorescent polymer; Figure 10.c is a schematic diagram of the laser focus located on the substrate and the fluorescent polymer Schematic diagram of the spot image at the interface; Figure 10.d is a schematic diagram of the spot image when the laser focus is at an ideal position. Because the physical properties of fluorescent polymers are different, the ideal processing position actually selected is not exactly located on the interface. Taking photoresist as an example, when the equivalent diameter of the fluorescent spot in the spot image reaches 2/3 of the reference value, the laser focus is just at the ideal processing position. That is, 2/3 of the reference value is the ideal value of the equivalent diameter of the spot.

S24: Adjust the height of the base until the equivalent diameter of the spot in the spot image is equal to an ideal value.

Due to the tiny size of the laser focus, it is only 0.5-2μm. Even under the objective lens, it is difficult to focus precisely. Through the fluorescent effect of fluorescent polymers, laser focus focusing is converted into image processing, which effectively improves the accuracy of focusing. At the same time, the efficiency of image recognition is higher than that of human eye observation, which can also avoid eye injuries and improve the safety of focusing. sex.

S3: Controlling the substrate to move to the next processing point according to the preset moving path. Determine whether the equivalent diameter of the spot in the spot image is equal to the ideal value, and make the following decisions:

(1) Yes, laser processing is performed directly at this position. When the equivalent diameter of the spot in the spot image is equal to the ideal value, the focus is completed at the processing point, and laser processing can be performed directly according to the processing strategy.

(2) Otherwise, focus at the processing point, and perform laser processing at the processing point after focusing. In the process of laser processing, after laser processing is completed at any processing point, the substrate only moves in the horizontal direction. Since there is an angle between the tilt direction of the substrate and the horizontal plane, and the height of the substrate changes after processing, it is necessary to continue focusing To confirm the actual processing position.

Please refer to FIG. 11 , which is a schematic diagram of the moving direction of the substrate in FIG. 3 . In this embodiment, the movement of the substrate is a three-dimensional movement, with the initial processing point as the origin, the vertical direction as the Z axis, any horizontal direction as the X axis, and the other horizontal direction perpendicular to the X axis as the Y axis. Then the movement path of the substrate between the various processing points only includes the movement of the substrate on the X-axis and the Y-axis. The focusing process only involves movement of the substrate in the Z axis.

S4: Determine whether the processing is completed, if not, repeat S3 until the processing is completed. If the processing is completed, the processed micro-nano structure is developed to obtain a finished micro-nano structure.

Since the designed structure is a three-dimensional micro-nano structure, the fluorescent polymer needs to be processed at multiple points on the substrate. According to the design structure and the completed processing position, it can be judged whether the processing is completed. After the processing of the micro-nano structure is completed, the micro-nano structure needs to be developed to remove the part of the micro-nano structure that exceeds the designed structure to obtain the finished micro-nano structure.

The two-photon automatic processing method for non-flat substrates provided in this embodiment adopts the method of point-point focusing and fluorescent focusing, by converting the focusing of the laser focus into fluorescent image recognition, and confirming whether the focusing is completed according to the equivalent diameter of the spot, Effectively improve focusing efficiency and focusing accuracy. In addition, by automatically focusing on each processing point, the problem of complicated, time-consuming manual focusing operations and large errors in the process of using lasers to process non-flat substrates is solved. In order to realize two-photon automatic processing for non-flat substrates, this embodiment also provides a two-photon automatic processing system for non-flat substrates. The processing system includes imaging module, image processing module, decision-making module and displacement control module.

The imaging module is used for real-time acquisition of light spot images containing fluorescent polymers and their scattered fluorescence. The fluorescent polymer produces a fluorescent effect under the irradiation of the laser focus, and an image including the fluorescent polymer and its scattered fluorescence is obtained by real-time shooting of the substrate and the fluorescent polymer. The spot image collected by the imaging module is transmitted to the image processing module.

The image processing module is used for preprocessing the spot image and calculating the equivalent diameter of the spot in the spot image. The preprocessing of spot image includes normalization processing and filtering processing. Normalization processing can convert each spot image into the same form, maintain the same standard in the process of multiple processing, and improve the processing accuracy. Filtering can suppress the noise of the image and improve the accuracy of image processing under the premise of retaining the details of the image. The equivalent diameter of the spot can be obtained through the image recognition model. For example, first use the color threshold method to convert the color space of the image into the HSV color space, and then extract the light spots according to the color threshold. Then the pattern recognition model is used to add the minimum circumscribed circle on the spot, and the diameter of the circumscribed circle is obtained as the equivalent diameter of the spot.

The decision-making module is used for: 1. judging whether the equivalent diameter of the light spot is the maximum value, and if so, recording the maximum value of the equivalent diameter as a reference value.

The relationship between the equivalent diameter of the fluorescent spot and the position of the laser focus is as follows: when the laser focus is completely in the substrate, the fluorescent polymer does not produce a fluorescent effect, so there is no fluorescent spot in the spot image. When the laser focus moves from the substrate to the fluorescent polymer until it touches the fluorescent polymer, the fluorescent polymer produces a fluorescent effect, and fluorescent spots begin to appear in the spot image. When the laser focus continues to move into the fluorescent polymer until the center of the laser focus is just at the interface between the substrate and the fluorescent polymer, the fluorescence effect produced by the fluorescent polymer reaches the maximum, and the equivalent diameter of the spot in the spot image also reaches the maximum. The laser focus continues to move until it is completely in the fluorescent polymer, and the size of the spot in the spot image does not change.

It can be seen that when the equivalent diameter of the fluorescent spot reaches the maximum, the laser focus is just located on the interface between the substrate and the fluorescent polymer. The interface between the substrate and the fluorescent polymer is the reference plane for processing.

2. Determine whether the equivalent diameter of the light spot is an ideal value, and if so, confirm that the focus is completed.

Because the physical properties of fluorescent polymers are different, the ideal processing position actually selected is not exactly located on the interface. Taking photoresist as an example, when the equivalent diameter of the fluorescent spot in the spot image reaches 2/3 of the reference value, the laser focus is just at the ideal processing position. That is, 2/3 of the reference value is the ideal value of the equivalent diameter of the spot.

The displacement control module is used for: Ⅰ. Outputting a displacement signal according to a preset movement path, and then controlling the movement table to drive the base to move horizontally. In the process of laser processing, it is necessary to set up multiple processing points, and perform laser processing at each processing point. In order to ensure that the processed three-dimensional micro-nano structure conforms to the design structure as much as possible, the processing point is positioned on the substrate by horizontal movement.

Ⅱ. Output the displacement signal according to the preset processing strategy, and then control the motion table to drive the three-dimensional movement of the base. At any processing point, depending on the design structure, the moving path of the laser focus is also different. The processing of three-dimensional micro-nano structures requires movement in at least three degrees of freedom.

Ⅲ. When focusing, output the lifting signal to control the motion table to drive the base to rise and fall. For any processing point, after finding the horizontal position of the processing point, it only needs to complete the focusing by lifting the base. The focusing method includes: acquiring a spot image of the fluorescent polymer and its scattered fluorescence, and adjusting the height of the substrate until the equivalent diameter of the spot in the spot image is equal to an ideal value.

For any processing point, the method of focusing may also include: adjusting the height of the substrate so that the laser focus is just on the interface between the substrate and the fluorescent polymer, that is, the equivalent diameter of the spot in the spot image just increases to the reference value or just from The base value starts to decrease, and moves up or down by a preset distance to make the equivalent diameter of the spot in the spot image equal to the ideal value. During the focusing process, the upward or downward movement of the substrate can be determined according to the relative position of the substrate and the fluorescent polymer. If the base is located under the fluorescent polymer, when the equivalent diameter of the spot in the spot image is equal to the reference value, move the base up to move the laser focus toward the base, then the equivalent diameter of the spot in the spot image will gradually decrease, and the recording focus The distance to move from the reference plane to the ideal machining plane. After that, after each focus, it is only necessary to move the substrate down by a corresponding distance after the laser focus reaches the reference plane.

Please refer to FIG. 12 , which is a schematic diagram of the laser path of the two-photon automatic processing equipment for non-flat substrates using the two-photon automatic processing method for non-flat substrates in FIG. 3 . In this embodiment, according to the two-photon automatic processing method and system for non-flat substrates, the existing two-photon direct writing processing equipment is optimized to obtain a two-photon automatic processing equipment for non-flat substrates. The processing equipment includes a laser, a moving stage, a substrate, an optical path regulator, an objective lens, an imaging device and a controller.

Lasers are used to emit laser light. This embodiment uses a femtosecond laser. The femtosecond laser is a ChameleonVision-S laser produced by Coherent Company. The output wavelength adjustment range is 690nm to 1050nm, the laser pulse width is 75fs, the repetition frequency is 80MHz, and the average output power is 2.5W. The laser wavelength used in laser two-photon processing is 800nm. Of course, in other embodiments, the laser can also be a pulsed laser or a continuous laser, as long as it can emit the laser required for laser processing.

The substrate is used to carry the fluorescent polymer, so that the fluorescent polymer is located on the path of the laser light, and the fluorescent polymer produces a fluorescent effect when irradiated by the laser light. In this embodiment, PDMS is used as a flexible non-flat substrate, and a fluorescent polymer is dropped on the flexible substrate. Under the action of laser light, PDMS produces a light spot that is clearly different from that of the fluorescent polymer. Of course, in other embodiments, the substrate may also be made of transparent materials such as plastic sheets, so that the laser light can pass through the substrate and irradiate on the fluorescent polymer. In this embodiment, photoresist (SZ2080) is used as the fluorescent polymer, and the photoresist has a fluorescent effect. Before processing, place the photoresist on the slide and bake in a hot oven at 60° for 15 minutes. Of course, in other embodiments, the fluorescent polymer can also use photosensitive resins, photosensitive hydrogels and other photosensitive materials with fluorescent effects or doped with fluorescent effect substances, as long as they are three-dimensionally formed into the designed structure after laser processing and development. Can. Of course, when other fluorescent polymers are selected, the ratio of the ideal value of the equivalent diameter of the spot in the spot image to the reference value also changes accordingly, and the ratio is set according to the physical properties of the fluorescent polymer used.

The motion table is fixedly connected with the base, and is used to drive the base to move. The base can be fixedly connected to the moving table by means of magnetic attraction to ensure that the base does not shift when the moving table drives the base to move. In this embodiment, a PI-E545 nano-motion stage is used, which can drive the substrate to move in three directions of x, y, and z. The PI-E545 nano motion table is electrically connected to the controller, and its movement is controlled by the controller. During laser processing, the substrate is deflected at different angles around the x-axis and y-axis, so that the laser focus can be scanned in the xy plane, and the height of the substrate can be directly adjusted by lifting and moving in the z-axis direction. Of course, in other embodiments, other micro-scale or nano-scale motion stages can also be used, as long as the precise movement of the substrate in three-dimensional space can be realized.

The optical path regulator is arranged on the emission path of the laser, and is used to adjust the intensity and direction of the laser, so that the laser can be used for processing or focusing respectively. The optical path adjuster includes a light gate and a pre-adjuster beam splitter. The pre-regulator is arranged on the laser emission path of the laser, and is used for adjusting the energy and phase of the laser.

The pre-regulator includes a Glan Taylor prism, a half-wave plate, a beam expander, a reflector and an attenuation plate arranged in sequence along the laser emission path. Glan Taylor prisms are used to control the energy of laser beams. The Glan-Taylor prism is set on the emission path of the laser and is used to convert the laser light into polarized light. The Glan Taylor prism is a birefringent polarizer made of natural calcite crystals, the main component of which is rhombohedral crystals of CaCO ₃ . Inputting an unbiased collimated laser beam into the Glan-Taylor prism can obtain a beam of linearly polarized light (e light). Compared with other polarizers, Glan Taylor prisms have higher light transmittance and polarization purity. Half-wave plates are used to adjust the phase of the laser beam. A half-wave plate is a birefringent crystal with a certain thickness. When the normal incident light passes through, the phase difference between ordinary light (o light) and linearly polarized light (e light) is equal to π or an odd multiple of π. Beam expanders are used to increase the diameter of a laser beam. A beam expander is a lens assembly that changes the diameter and divergence of a laser beam. The laser emitted from the laser has a certain divergence angle, and the laser beam becomes a collimated (parallel) laser beam through the adjustment of the beam expander. The reflector is used to adjust the emission direction of the laser beam. Attenuators are used to adjust the energy of the laser beam. Taking advantage of the light absorption characteristics of the material, the material is made into a sheet and placed on the optical path adjustment component to attenuate the light intensity. This sheet-like component is called an optical attenuation sheet. How much light passes through the attenuating sheet is related to the type of material, and also related to the thickness of the material.

The light gate is arranged between the laser and the pre-regulator, and is used to control the on-off of the laser.

The beam splitter is arranged on the laser output path of the pre-adjuster, and is used to reflect the processed laser and transmit the imaging light, and respectively make the reflected laser incident on the objective lens and the transmitted light enter the imaging device. In this embodiment, the beam splitter is a dichroic mirror, which has the characteristics of reflecting infrared light with a wavelength of 750-850nm and transmitting visible light with a wavelength of 400-700nm. The 800nm wavelength laser emitted by the laser is reflected by the mirror and then incident on the objective lens vertically, while other visible light is directly transmitted to avoid affecting the processing or focusing process. In addition, the wavelength of fluorescence emitted by fluorescent polymers is generally between 450-600nm, and it will also be directly transmitted through the beam splitter and captured by the camera, which can not only improve the clarity of fluorescence imaging, but also avoid the damage caused by fluorescence to laser processing. interference.

Of course, in other embodiments, the optical path adjustment component can also be replaced by a light guide element such as an optical fiber, as long as the laser can be converted into a collimated laser beam and be perpendicularly incident on the objective lens.

The objective lens is arranged on the laser output path of the optical path adjuster, and is used for focusing the laser light. In this embodiment, the magnification of the objective lens is 50 times, and the numerical aperture of the objective lens is 0.8. Of course, in other embodiments, the magnification and numerical aperture of the objective lens can be larger or smaller.

The imaging device is arranged on the fluorescence path scattered by the fluorescent polymer, and is used for real-time collection of light spot images including the fluorescent polymer and its scattered fluorescence. The imaging device is also used to transmit the collected light spot images to the controller. In this embodiment, the imaging device is a CCD camera. The CCD camera has the characteristics of small size, light weight, no influence of magnetic field and anti-vibration impact. The image collected by the CCD camera has the characteristics of high definition and easy transmission. Of course, in other embodiments, the imaging device can also be replaced with a photoelectric conversion element such as a photodiode, a phototransistor, etc., as long as the optical signal emitted by the substrate and the fluorescent polymer can be converted into an image or an electrical signal.

The controller is used for: 1. Controlling the moving table to adjust the horizontal position of the substrate so that the horizontal position of the laser focus is located in the initial processing area of the substrate. In the process of laser processing, the controller first generates a scanning strategy according to the designed micro-nano structure. The scanning strategy includes a horizontal movement path formed on the basis of multiple processing points and a processing strategy generated at each processing point. Subsequently, the substrate is moved so that the horizontal position of the laser focus is located in the preset initial processing area, so as to avoid structure loss caused by the processed micro-nano structure exceeding the surface of the substrate.

2. Focus the laser emitted by the laser so that the substrate is located at the ideal initial processing position, and perform laser processing at the initial processing position according to the corresponding processing strategy. After the laser focus is located in the initial processing area, the substrate needs to be moved to the ideal processing position, so as to avoid partial or complete loss of the processing structure. The focusing method includes: acquiring a spot image of the fluorescent polymer and its scattered fluorescence, and adjusting the height of the substrate until the equivalent diameter of the spot in the spot image is equal to an ideal value.

3. Control the motion table to drive the substrate to move according to the preset moving path, and then complete the corresponding laser processing at each processing point. Laser focusing is performed at each processing point to reduce or eliminate the influence of substrate unevenness on laser processing and improve the accuracy of laser processing.

4. Judging whether the equivalent diameter of the spot in the spot image is equal to the ideal value, if so, perform laser processing directly at this position. Otherwise, focus at the processing point, and perform laser processing at the processing point after focusing. Since the designed structure is a three-dimensional micro-nano structure, the fluorescent polymer needs to be processed at multiple points on the substrate. According to the design structure and the completed processing position, it can be judged whether the processing is completed. After the processing of the micro-nano structure is completed, the micro-nano structure needs to be developed to remove the part of the micro-nano structure that exceeds the designed structure to obtain the finished micro-nano structure.

The two-photon automatic processing equipment for non-flat substrates provided in this embodiment converts the focus of the laser focus into fluorescent image recognition, and confirms whether the focus is completed according to the equivalent diameter of the spot, effectively improving the focus efficiency and focus accuracy. Spend. In addition, by automatically focusing on each processing point, the problem of complicated, time-consuming manual focusing operations and large errors in the process of using lasers to process non-flat substrates is solved.

Experimental verification

Experiment 1: When the laser focus is at different positions, observe the relationship between the processed micro-nano structure and the designed structure.

A base with a sloped surface is used, and the base is fixedly connected to the motion table. Adjust the wavelength of the laser emitted by the laser to 800nm through the optical path adjuster, perform array processing in a horizontal direction, keep all processing points on the same horizontal plane, and obtain the microcolumn structural color as shown in Figure 13. Then, under the condition of keeping the substrate and the laser wavelength unchanged, each processing point was focused, and the obtained micro-column structural color is shown in Figure 14.

Please refer to Figure 13 and Figure 14, Figure 13 is the structural color and micro-column array due to the inconsistency of the relative height of the laser focus and the substrate surface; Figure 14 is the fluorescent color and micro-column array achieved after using autofocus. It can be seen that when each processing point is not focused, although the laser focus remains on the same horizontal plane, the relative height between the laser focus and the substrate changes due to the inclination of the substrate surface. On the processing path with a total length of 50 μm, The difference between the height of the micropillars processed at the first processing point and the height of the micropillars processed at the last processing point (6th processing point) is 1.5 μm, and the fluorescent colors scattered by each micropillar are green, blue, red, and orange in sequence , Yellow And Yellow.

The analysis is based on the experimental results, because the non-flat substrate will lead to inconsistencies in the height of the processed micropillar arrays of the same height. Among them, the reason for the micropillars with different structural colors is that the unevenness of the substrate leads to inconsistent processing heights, which in turn leads to different heights of the processed microstructures, thus causing structural color changes. The reason for the different heights of the micropillars is that the relative positions of the laser focus and the substrate surface are different, so the actual processing structure is inconsistent with the design structure parameters.

It can be seen from Figure 14 that the height of the processed microcolumns can be made consistent by using autofocus, and the structural color of each microcolumn is also red. In this experiment, the non-planarity error or inclination of the substrate processed by the experimental platform is between 1:50 and 1:25, which has a relatively large impact on the micro-nano structure. Therefore, the non-planar substrate effect is corrected by this method. When the initial position is positioned at the ideal processing position, record the size of the fluorescent spot at this time, and compare the size of the fluorescent spot generated in the subsequent processing array with the initial position. When there is an inconsistency, control the movement of the turntable until the size of the current fluorescent spot is equal to the original position. The size of the fluorescent spot at the initial position is the same. After autofocusing on the non-flat substrate through the two-photon direct writing process based on the fluorescence effect, the processed micropillar arrays are of consistent height, which can reduce the influence of the non-flat substrate variation on the processed structure.

Experiment 2: Processing micro-nano structures on patterned substrates with and without auto-focusing methods.

Please refer to FIG. 15 , which is an experimental comparison diagram of processing micro-nano structures at different positions on the patterned substrate. Among them, Figure 15a is a schematic structural diagram of a patterned substrate; Figure 15b is an effect diagram of processing a micro-nano array on a patterned substrate without using an automatic processing method; Figure 15c is an effect diagram of processing a micro-nano array on a patterned substrate by adjusting the focus position . Using a patterned substrate as shown in Figure 15a, the patterned substrate can be obtained using photolithographic methods. The specific process is to spin-coat a layer of SU-8 photoresist with a thickness of 50 microns on the glass slide, and use a photolithography machine (model: ABM6350) to expose the patterned photoresist. After exposure, use a developer to remove the excess, and form a groove structure with a designed width on the surface of the glass by the photoresist structure. In this experiment, the groove depth is 50 microns, and the width is 80-150 microns.

SZ2080 photoresist was added dropwise on the patterned substrate, and pre-baked at 100 degrees for 30 minutes. The substrate is fixedly connected to the moving stage, and the laser wavelength emitted by the femtosecond laser is adjusted to 800nm through an optical path regulator, followed by array processing.

It can be seen from Figure 15b and Figure 15c that when automatic processing is not performed on each processing point, although the laser focus remains on the same level, the processed substrate is a groove structure, and the transition between the bottom of the groove and the side wall Due to the variation of the substrate height in the area, the processed micropillar height is significantly different from the micropillar height at the bottom of the trench. As a result, part of the processed microcolumns collapsed and deformed, and the processing effect was not good. However, when using the focus adjustment method, it can be seen that the height of the processed micro-column array is consistent, and the overall processing effect is better without collapse and deformation.

Therefore, the influence of the non-planar substrate on processing can be corrected through the automatic processing method of the present invention, and a complete three-dimensional micro-nano structure array on the non-flat substrate can be realized.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A two-photon automatic processing method for non-flat substrates, characterized in that it comprises the following processes: S1: Adjust the horizontal position of the substrate so that the horizontal position of the laser focus is located in the initial processing area of the substrate; the initial processing area means that when any point in this area is used as the initial processing point, the horizontal area where the design structure is located is located on the base; S2: Focus the laser so that the substrate is located at the ideal initial processing position, and perform laser processing at the initial processing position according to the corresponding processing strategy; the focusing method is as follows: S21: Taking the fluorescent polymer as the viewfinder object, collecting the spot image of the fluorescent polymer scattering fluorescence in real time; S22: adjust the height of the base, and when the equivalent diameter of the spot in the spot image reaches a maximum value, calculate the maximum equivalent diameter of the spot as a reference value; S23: Calculate the ideal value of the equivalent diameter of the spot according to the physical properties of the fluorescent polymer and the reference value; S24: adjusting the height of the substrate until the equivalent diameter of the spot in the spot image is equal to an ideal value; S3: Control the substrate to move to the next processing point according to the preset moving path; judge whether the equivalent diameter of the spot in the spot image is equal to the ideal value, and make the following decisions: (1) If yes, laser processing is performed directly at this position; (2) Otherwise, focus at the processing point, and perform laser processing at the processing point after focusing; S4: Determine whether the processing is completed, if the processing is not completed, repeat S3 until the processing is completed; if the processing is completed, develop the processed micro-nano structure to obtain a finished micro-nano structure. 2. The two-photon automatic processing method for non-flat substrates according to claim 1, wherein in S1, the initial processing area is calculated according to the horizontal area covered by the substrate and the horizontal area covered by the scanning strategy , the specific method is as follows: a. Map the outline p _j of the substrate, the outline p _l of the laser focus, the horizontal area p _p covered by the processing strategy, and the horizontal area p _s covered by the scanning strategy on the same plane; set p _l and p _p concentrically, and Move within p _j along the path tangent to p _p and p _j for one week; remove the area surrounded by p _l and p _j from p _j to get the intermediate shape p _m ; b. Scale p _m until the zoomed figure is just circumscribed on p _s ; let p _m be an n-gon, and the figure circumscribed on p _s is p _ms , then paste the n corners of p _ms in turn are combined on each corner of the corresponding p _m ; each time it is combined, an extension line is made for the other n-2 sides that are not adjacent to the corner of the joint; multiple extension lines divide p _s into multiple points area; the sub-area containing each corner of p _m is used as the initial processing area. 3. The two-photon automatic processing method for non-flat substrates according to claim 1, wherein in S1, the method for judging that the laser focus is located in the initial processing area is as follows: S11: taking the substrate as a viewfinder object, collecting a substrate image including a laser focus; S12: Preprocessing the substrate image, retaining the outer contour of the substrate and the outer contour of the laser focus; S13: adding the outline of the initial processing area to the outer outline of the base; S14: Observe whether the outer contour of the laser focus is completely in the initial processing area, if yes, confirm that the laser focus is in the initial processing area; otherwise, move the substrate until the outer contour of the laser focus is completely in the initial processing area. 4. the two-photon automatic processing method for non-flat substrate according to claim 1, is characterized in that, in S22, the method for obtaining reference value is as follows: S221: Observe whether there is a spot in the initial spot image, and make the following decision: if there is no spot, move the base up and down until the spot appears in the spot image; if there is a spot, control the base to move up or down, and observe the size of the spot Variety; S222: Determine whether the size of the light spot increases, and make the following decision: if the light spot becomes smaller gradually, move the substrate in the opposite direction to make the size of the light spot in the light spot image larger; if the light spot gradually becomes larger, control the base to continue in the original direction Move until the size of the spot remains unchanged; if the spot remains unchanged, the equivalent diameter of the spot reaches the maximum, and the minimum circumscribed circle of the spot is obtained, and the diameter of the minimum circumscribed circle is the reference value. 5. The two-photon automatic processing method for non-flat substrates according to claim 1, characterized in that, in S3, the movement of the substrate is a three-dimensional movement, with the initial processing point as the origin, and the vertical direction as the Z axis, Any horizontal direction is the X axis, and the other horizontal direction perpendicular to the X axis is the Y axis; then the movement path only includes the movement of the substrate on the X axis and the Y axis; the focusing process only includes the movement of the substrate on the Z axis. 6. A two-photon automatic processing system for non-flat substrates, which adopts the two-photon automatic processing method for non-flat substrates according to any one of claims 1 to 5, characterized in that it comprises: An imaging module, which is used for real-time acquisition of spot images comprising fluorescent polymers and their scattered fluorescence; An image processing module, which is used for preprocessing the spot image, and calculating the equivalent diameter of the spot in the spot image; Decision-making module, which is used for: 1. Judging whether the equivalent diameter of the light spot is the maximum value, and if so, recording the maximum value of the equivalent diameter as a reference value; 2. Judging whether the equivalent diameter of the light spot is an ideal value, and then confirming the focus Finish; The displacement control module is used for: Ⅰ. Outputting displacement signals according to a preset moving path, and then controlling the horizontal movement of the base driven by the motion table; Ⅱ. Outputting displacement signals according to a preset processing strategy, and then controlling the three-dimensional movement of the base driven by the motion table; Ⅲ. When focusing, output the lifting signal to control the motion table to drive the base to rise and fall. 7. A two-photon automatic processing device for non-flat substrates, which is used to process the fluorescent polymer to be processed into a corresponding three-dimensional micro-nano structure according to the design structure; it adopts any one of claims 1 to 5 The described two-photon automatic processing method for non-flat substrates; the processing equipment includes a laser, a moving table and a substrate; the laser is used to emit laser light; the substrate is used to carry a fluorescent polymer, so that the fluorescent polymer Located on the laser path, the fluorescent polymer is irradiated by the laser to produce a fluorescent effect; the moving table is fixedly connected to the substrate and used to drive the substrate to move; it is characterized in that the processing equipment also includes: An optical path regulator, which is arranged on the emission path of the laser, is used to adjust the intensity and direction of the laser, so that the laser is used for processing or focusing respectively; The objective lens is arranged on the laser output path of the optical path adjuster, and is used for focusing the laser light; An imaging device, which is arranged on the fluorescence path scattered by the fluorescent polymer, is used for real-time collection of spot images comprising the fluorescent polymer and its scattered fluorescence; and a controller, which is used to: 1. control the moving table to adjust the horizontal position of the substrate, so that the horizontal position of the laser focus is located in the initial processing area of the substrate; 2. focus the laser emitted by the laser, So that the substrate is located at the ideal initial processing position, laser processing is performed at the initial processing position according to the corresponding processing strategy; 3. Control the movement table to drive the substrate to move according to the preset movement path, and then complete the corresponding processing at each processing point. 4. Judging whether the equivalent diameter of the spot in the spot image is equal to the ideal value, if so, perform laser processing directly at the position; otherwise, focus at the processing point, and perform laser processing at the processing point after focusing. 8. The two-photon automatic processing equipment for non-flat substrates according to claim 7, wherein the optical path adjuster comprises an optical gate, a pre-adjuster and a beam splitter; the pre-adjuster is arranged at On the laser emission path of the laser, it is used to adjust the energy and phase of the laser; the optical gate is arranged between the laser and the pre-adjuster, and is used to control the on-off of the laser; the beam splitter is arranged on the On the laser output path of the pre-regulator, the beam splitter is used to reflect the incident laser light used for micro-nano processing into the objective lens, and the image and fluorescence signal of the processed place enter the imaging device through the beam splitter. 9. The two-photon automatic processing equipment for non-flat substrates according to claim 8, wherein the pre-adjuster includes a Glan-Taylor prism, a half-wave plate, and a beam expander arranged in sequence along the laser emission path. The Glan Taylor prism is used to control the energy of the laser beam; the half-wave plate is used to adjust the phase of the laser beam; the beam expander is used to adjust the diameter of the laser beam; The mirror is used to adjust the emission direction of the laser beam; the attenuation sheet is used to adjust the energy of the laser beam. 10. The two-photon automatic processing equipment for non-flat substrates according to claim 7, wherein the laser is a femtosecond laser; the imaging device is a CCD camera; the moving stage is a three-dimensional micro-nano movement tower.

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