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

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

Technical Field

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

Background

Femtosecond laser micro-nano processing is a novel nano structure forming method. It can be seen as a special 3D printing, i.e. a stereolithography technique. In the femtosecond laser two-photon direct writing processing focusing process, workers need to find the interface between a two-photon material and a substrate as a processing reference surface. The relative position of a two-photon processing material and a laser focus on the substrate is controlled by controlling the three-dimensional motion platform, and after a proper processing reference surface is found, the two-photon material is directly processed by femtosecond laser two-photon.

Two conditions occur when the laser focus is offset from the machining reference plane: a) When the laser focus is mostly in the middle of the substrate material, the processing structure is incomplete compared with the design structure, and partial processing structure is lost after development. b) When the focus is completely in the polymer material, the machined structure is not attached to the substrate, and the machined structure is washed away after development, resulting in complete loss of the structure.

Non-flat substrates can be broadly classified into three cases during processing: 1.a flexible substrate (see fig. 1. A). 2. The substrate is patterned (see fig. 1. B). 3. The substrate is tilted (see fig. 1. C).

And (3) processing the micro-nano structure on the flexible substrate material by using a femtosecond laser (as shown in figure 2. A). Due to the irregular change of the substrate surface topography, the micro-nano structure of the subsequent processing is lost or completely lost after the focusing of the initial position is completed (as shown in fig. 2. B). Currently, workers solve this problem by machining one structure, manually focusing again and then continuing to machine the next structure (see fig. 2.c). However, the method is complicated to operate, the axial position of the focus is determined by observing the size of the light spot when the laser and the material to be processed act through naked eyes during manual focusing, and the processing quality is affected due to large random errors caused by the naked eye observation.

Disclosure of Invention

Therefore, the problems that the manual focusing operation is complicated, time-consuming and has large errors in the existing process of processing the non-flat substrate by using the laser are necessarily solved. A two-photon automated processing method, system and apparatus for non-planar substrates is presented.

The invention is realized by the following technical scheme: a two-photon automated processing method for non-planar substrates, comprising the steps of:

s1: and adjusting the horizontal position of the substrate to enable the horizontal position of the laser focus to be positioned in the initial processing area of the substrate. The initial processing region is characterized in that when an optional point in the region is used as an initial processing point, the horizontal region where the designed structure is located is positioned on the substrate.

S2: and focusing the laser to enable the substrate to be located at the ideal initial processing position, and performing laser processing at the initial processing position according to the corresponding processing strategy. The focusing method comprises the following steps:

s21: and collecting a light spot image of the fluorescent polymer scattered fluorescence in real time by taking the fluorescent polymer as a view finding object.

S22: and adjusting the height of the substrate, and calculating 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 the maximum value.

S23: and calculating an ideal value of the equivalent diameter of the light spot according to the physical characteristics of the fluorescent polymer and the reference value.

S24: the height of the substrate is adjusted until the equivalent diameter of the spot in the spot image is equal to the desired value.

S3: controlling the substrate to move to the next processing point according to a preset moving path, judging whether the equivalent diameter of the facula in the facula image is equal to an ideal value, and making the following decision:

(1) Laser machining is performed directly at that location.

(2) Otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished.

S4: and judging whether the machining is finished or not, and if the machining is not finished, repeating the step S3 until the machining is finished. And if the processing is finished, developing the processed micro-nano structure to obtain a 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 the femtosecond laser on the non-flat substrate are solved.

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

a. the outline p of the substrate _j Profile p of laser focus _l Horizontal area p covered by the machining strategy _p And the horizontal area p covered by the scanning strategy _s The mapping is on the same plane. P is to be _l And p _p Are concentrically arranged and are in p _j Inner edge p _p And p _j The tangential path moves one revolution. P is to be _l And p _j Enclosed region from p _j Removing to obtain an intermediate profile p _m 。

b. To p _m Zooming is carried out until the zoomed graph is just externally connected with p _s The above. Let p _m Is n-polygonal and is externally connected with p _s Is a pattern of p _ms Then p will be _ms Are sequentially attached to corresponding p _m At each corner of the panel. And during each attaching, making extension lines on other n-2 sides which are not adjacent to the attached corners. Multiple extension lines p _s Dividing into multiple subareas, including p _m As an initial machining area.

In one embodiment, the method for determining that the laser focus is located in the initial processing region is as follows:

s11: and taking the substrate as a view finding object, and acquiring a substrate image containing a laser focus.

S12: and (4) preprocessing the substrate image, and reserving the outer contour of the substrate and the outer contour of the laser focus.

S13: and adding the contour line of the initial processing area in the outer contour of the substrate.

S14: and observing whether the outer contour of the laser focus is completely positioned in the initial processing area, and if so, confirming that the laser focus is positioned in the initial processing area. Otherwise, the substrate is moved until the outer contour of the laser focus is completely in the initial processing area.

In one embodiment, the method for obtaining the reference value is as follows:

s221: and observing whether the light spots exist in the initial light spot image, and making the following decision: and if no light spot exists, lifting the substrate until the light spot appears in the light spot image. And if the light spot exists, controlling the substrate to move upwards or downwards, and observing the size change of the light spot.

S222: judging whether the size of the light spot is increased or not, and making the following decision: and if the light spot is gradually reduced, reversely moving the substrate to enlarge the size of the light spot in the light spot image. And if the light spot is gradually enlarged, controlling the substrate to continuously move along the original direction until the size of the light spot is kept unchanged. If the light spot is kept unchanged, the equivalent diameter of the light spot is maximized, the minimum circumscribed circle of the light spot is obtained, and the diameter of the minimum circumscribed circle is the reference value.

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

The present invention also provides a two-photon automated processing system for non-flat substrates, comprising:

the imaging module is used for acquiring a light spot image containing the fluorescent polymer and the scattered fluorescence thereof in real time.

The image processing module is used for preprocessing the light spot image and calculating the equivalent diameter of the light spot in the light spot image. The preprocessing of the light spot image comprises normalization processing and filtering processing. The normalization processing can convert each light spot image into the same form, the same standard is kept in the process of multiple times of processing, and the processing precision is improved. The filtering processing can inhibit the noise of the image on the premise of keeping the detail characteristics of the image, and the accuracy of the image processing is improved.

The decision module is to: 1. and judging whether the equivalent diameter of the light spot is the maximum value or not, and if so, recording the maximum value of the equivalent diameter as a reference value. 2. And judging whether the equivalent diameter of the light spot is an ideal value or not, and if so, confirming that the focusing is finished.

The displacement control module is used for: and I, outputting a displacement signal according to a preset moving path, and further controlling the moving table to drive the substrate to horizontally move. And II, outputting a displacement signal according to a preset processing strategy, and further controlling the motion platform to drive the substrate to move in a three-dimensional manner. And III, outputting a lifting signal during focusing, and controlling the moving platform to drive the substrate to lift.

The invention also provides two-photon automatic processing equipment for the non-flat substrate, which comprises a laser, a motion table, an optical path regulator, an objective lens, an imaging device and a controller.

The laser is used for emitting laser light. The substrate is used for bearing the fluorescent polymer, so that the fluorescent polymer is positioned on a laser path, and the fluorescent polymer generates a fluorescent effect when being irradiated by laser. The motion platform is fixedly connected with the substrate and used for driving the substrate to move. The substrate can be fixedly connected with the motion table through methods such as magnetic attraction and the like so as to ensure that the substrate cannot deviate when the motion table drives the substrate to move.

The light path regulator is arranged on the emission path of the laser and is used for regulating the intensity and the direction of the laser so as to enable the laser to be used for processing or focusing respectively. The objective lens is arranged on a laser emergent path of the optical path regulator and used for focusing laser. The imaging device is arranged on a fluorescent path scattered by the fluorescent polymer and is used for acquiring a spot image containing the fluorescent polymer and the scattered fluorescence thereof in real time. The imaging device is also used for transmitting the acquired spot image to the controller.

The controller is used for: 1. and controlling the motion table to adjust the horizontal position of the substrate, so that the horizontal position of the laser focus is positioned in the initial processing area of the substrate. 2. And focusing laser emitted by the laser so as to enable the substrate to be positioned at an ideal initial processing position, and carrying out laser processing at the initial processing position according to a corresponding processing strategy. 3. And controlling the motion table to drive the substrate to move according to a preset moving path, and further finishing corresponding laser processing on each processing point. 4. And judging whether the equivalent diameter of the light spot in the light spot image is equal to an ideal value or not, and if so, directly carrying out laser processing at the position. Otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished.

In one embodiment, the optical path adjuster includes a shutter, a pre-adjuster, and a beam splitter. The pre-regulator is arranged on a laser emission path of the laser and is used for regulating the energy and the phase of the laser. The optical shutter is arranged between the laser and the preposed regulator and used for controlling the on-off of the laser. The spectroscope is arranged on a laser emergent path of the front regulator and used for reflecting the processed laser and transmitting imaging light. The light path regulator is adopted to regulate the energy and the phase of the laser, so that the laser can be respectively used for processing and focusing, and simultaneously, the laser is divided into a transmission beam and a reflection beam, so that the laser focusing and the light spot image acquisition can be synchronously completed, and the laser focusing efficiency and the laser focusing accuracy are improved

In one embodiment, the pre-conditioner includes a Glan Taylor prism, a half-wave plate, a beam expander, a mirror, and an attenuation plate 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 for adjusting the phase of the laser beam. The beam expander is used for increasing the diameter of the laser beam. The reflecting mirror is used for adjusting the emission direction of the laser beam. The attenuation sheet is used for adjusting the energy of the laser beam.

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

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

1. 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 the femtosecond laser on the non-flat substrate are solved.

2. The invention adopts a fluorescence focusing method, and confirms whether the focusing is finished or not according to the equivalent diameter of the facula by converting the focusing of the laser focus into the fluorescence image recognition, thereby effectively improving the focusing efficiency and the focusing accuracy.

3. According to the invention, the micro-nano structure obtained by laser processing can be just positioned on the substrate by presetting the initial processing area, so that the partial loss of the micro-nano structure is avoided, and the processing efficiency is improved.

4. The three-dimensional micro-nano-scale motion platform is adopted to drive the substrate to move, the substrate can be driven to move randomly in a three-dimensional range, the laser processing equipment can complete the processing of a complex three-dimensional structure, and meanwhile the focusing accuracy and the focusing efficiency of the processing equipment are improved.

5. The light path regulator is adopted to regulate the energy and the phase of the laser, so that the laser can be used for processing and focusing respectively, and the laser is divided into a transmitting beam and a reflecting beam, so that the laser focusing and the light spot image acquisition can be completed synchronously, and the efficiency and the accuracy of the laser focusing are improved.

Drawings

FIG. 1 is a classification diagram of a non-flat substrate in the background art of the present invention;

FIG. 2 is a distortion diagram of a three-dimensional micro-nano structure in the background art of the invention;

FIG. 3 is a flowchart of a two-photon automated processing method for non-flat substrates according to example 1 of the present invention;

FIG. 4 is a diagram of the intermediate profile p of FIG. 3 taken of the initial machining region _m A schematic diagram of (a);

FIG. 5 is a schematic view of the angular fit of the ideal initial processing region of FIG. 3;

FIG. 6 is a schematic illustration of the location of the ideal initial machining region of FIG. 3;

FIG. 7 is a schematic view of the actual initial processing region of FIG. 3 showing angle fitting;

FIG. 8 is a schematic illustration of the actual initial machining area of FIG. 3;

FIG. 9 is a graph showing the relationship between the relative position of the laser focus in FIG. 3 and the size change of the fluorescent spot and the final machining result;

FIG. 10 is a schematic diagram showing the sizes of fluorescent light spots when the laser focus points are located at different positions in FIG. 3;

FIG. 11 is a schematic view of the direction of movement of the substrate of FIG. 3;

FIG. 12 is a schematic laser path of a two-photon automated processing apparatus for non-flat substrates using the two-photon automated processing method for non-flat substrates of FIG. 3;

FIG. 13 is a diagram of the fluorescence color and micropillar array at different heights of the laser focus relative to the substrate surface;

FIG. 14 is a diagram of fluorescent color and microcolumn arrays achieved after use of automatic focusing;

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

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, 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 invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the 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 flowchart illustrating a two-photon automatic processing method for a non-planar substrate according to the present embodiment. The two-photon automatic processing method for the non-flat substrate comprises the following steps:

s1: and adjusting the horizontal position of the substrate to enable the horizontal position of the laser focus to be positioned in the initial processing area of the substrate. The initial processing region is characterized in that when an optional point in the region is used as an initial processing point, the horizontal region where the design structure is positioned on the substrate.

In the embodiment, the laser two-photon processing is carried out on the fluorescent polymer to be processed into a micro-nano structure with the size consistent with the size of the designed structure on the substrate according to the designed structure. In order to ensure that the micro-nano structure of the laser processing is completely positioned on the substrate, the initial processing point of the laser processing needs to be positioned. In this embodiment, an initial processing region is preset on a substrate, a laser focus is positioned in the initial processing region, and laser two-photon processing is performed according to an initial processing point and a placement direction of the substrate, so that a processed micro-nano structure is completely located on the surface of the substrate.

Referring to fig. 4 to 8, fig. 4 is a diagram illustrating the intermediate profile p of the initial processing region obtained in fig. 3 _m A schematic diagram of (a); FIG. 5 is a schematic view of the angular fit of the ideal initial processing region of FIG. 3; FIG. 6 is a schematic view of the ideal initial machining area of FIG. 3; FIG. 7 is a schematic view of the actual initial processing region of FIG. 3 showing angle fitting; fig. 8 is a schematic position diagram of the actual initial processing region in fig. 3. The initial processing area is calculated according to the horizontal area covered by the substrate and the horizontal area covered by the scanning strategy, and the specific method is as follows:

a. the profile p of the substrate _j Profile p of laser focus _l Horizontal area p covered by the machining strategy _p And the horizontal area p covered by the scanning strategy _s The mapping is on the same plane. P is to be _l And p _p Are concentrically arranged and are in p _j Inner edge p _p And p _j The tangential path moves one revolution. P is to be _l And p _j The enclosed region is from p _j Removing to obtain an intermediate profile p _m 。

In this embodiment, the substrate is in the shape of a thin sheet, and the outline of the substrate is denoted as p _j . The laser focus is in an ellipsoid shape, the laser focus forms an elliptical projection on the horizontal plane, and the outline of the elliptical projection is marked as p _l . The projection of the micro-nano structure processed at each processing point on the horizontal plane is marked as p _p . In the scanning strategy, the polygon formed by connecting all the processing points is marked as p _m . Taking the center of a laser focus as a processing center, if the processed micro-nano structure is completely fallen on the substrate, p is _p Must not exceed p _j The initial machining area cannot therefore abut on the outer contour of the substrate.

b. To p is p _m Zooming is carried out until the zoomed graph is just externally connected with p _s The above. Let p _m Is n-polygonal and is externally connected with p _s A pattern of (1) is p _ms Then p will be _ms Are sequentially attached to corresponding p _m At each corner of the panel. And (3) during each bonding, making extension lines for other n-2 edges which are not adjacent to the bonded angle. Multiple extension lines p _s And dividing into a plurality of subareas. Will contain p therein _m The sub-area of each corner of (a) is used as an initial processing area.

Taking a rectangular substrate as an example, let the length of the substrate be l _j Width is d _j The major axis of the elliptical projection of the laser focus is l _l Minor axis of d _l . If the horizontal area p covered by the processing strategy _p And the horizontal area p covered by the scanning strategy _s Is also rectangular, and p _s Has a length of l _s Width of d _s ，p _p Has a length of l _p Width is d _p . Then p is _m Respectively has a length and a width of l _m ＝(l _j -l _p +l _l ) And d _m ＝(d _j -d _p +d _l ). The theoretical initial processing area comprises four rectangles at four corners, and the length and width of each rectangle are respectively (l) _m -l _s ) And (d) _m -d _s ). The actually selected initial processing area of 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 machining area is larger than the actually selected initial machining area. At p _j 、p _p And p _s When the processing areas are all standard rectangles, the calculation theory of the initial processing area not only can be used for the stepsThe steps are simpler and the area of the region is larger. However, at p _j 、p _p And p _s When all are non-standard rectangles, since p _m And p _s Have different outer contours, and cannot directly connect p _ms Angle of (a) and p _m The corner of (2) is bonded, and is difficult to handle directly. By making a pair of p _m Scaling to form p _ms Is externally connected to p _s In addition, the operation steps are greatly reduced, and the selection efficiency of the initial processing area is improved.

Referring to fig. 9 and 10, a method for determining that the laser focus is located in the initial processing area is as follows:

s11: and taking the substrate as a view finding object, and acquiring a substrate image containing a laser focus. Since the sizes of the substrate and the laser focus are both in the micron order, the position of the laser focus relative to the substrate is difficult to directly observe by naked eyes, so that the position of the laser focus relative to the substrate image is observed in a mode of imaging the substrate, and whether the laser focus is located in the initial processing area is further confirmed.

S12: and preprocessing the substrate image, and reserving the outer contour of the substrate and the outer contour of the laser focus. The preprocessing of the base image includes normalization processing and filtering processing. The normalization processing can convert the images into the same form, the same standard is kept in the process of multiple times of processing, and the processing precision is improved. The filtering processing can inhibit the noise of the image on the premise of keeping the detail characteristics of the image, and the accuracy of the image processing is improved. The outer contours of the substrate and the laser focus can be acquired by an image recognition model. The image processing is converted into mathematical graph processing, so that the processing process can be simplified, and the processing precision can be improved.

S13: adding the contour line of the initial processing area in the outer contour of the substrate. The initial processing region may be based on the profile p of the substrate _j Profile p of the laser focus _l Horizontal area p covered by the machining strategy _p And the horizontal area p covered by the scanning strategy _s And performing calculation, and adding the initial processing area to the base image.

S14: and observing whether the outer contour of the laser focus is completely positioned in the initial processing area, and if so, confirming that the laser focus is positioned in the initial processing area. Otherwise, the substrate is moved until the outer contour of the laser focus is completely in the initial processing area.

Whether the laser focus is in the initial processing area or not is observed through image processing, the accuracy of positioning the initial processing point can be effectively improved, and partial structure loss caused by the fact that the processed micro-nano structure exceeds the surface of the substrate is avoided.

S2: and focusing the laser to enable the substrate to be located at the ideal initial processing position, and performing laser processing at the initial processing position according to the corresponding processing strategy.

The focusing method comprises the following steps:

s21: and collecting a light spot image of the fluorescence scattered by the fluorescent polymer in real time by taking the fluorescent polymer as a view finding object. The fluorescent polymer generates a fluorescent effect under the irradiation of laser, the substrate is shot in real time by an imaging device such as a camera, and the substrate image containing fluorescent light spots can be extracted after video processing and picture processing.

S22: and adjusting the height of the substrate, and calculating 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 the maximum value.

The method for acquiring the reference value comprises the following steps:

s221: observing whether the light spots exist in the initial light spot image, and making the following decision: and if no light spot exists, lifting the substrate until the light spot appears in the light spot image. If the light spot exists, the substrate is controlled to move upwards or downwards, and the size change of the light spot is observed.

Please refer to fig. 9, which is a schematic diagram illustrating a relative position of the laser focus and a size variation of the fluorescent light 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, and therefore, there is no fluorescent spot in the spot image. When the laser focus moves from the substrate to the fluorescent polymer until it contacts the fluorescent polymer, the fluorescent polymer produces a fluorescent effect and a fluorescent spot begins to appear in the spot image. When the laser focus continuously moves to the fluorescent polymer until the center of the laser focus is just positioned at the interface of the substrate and the fluorescent polymer, the fluorescent effect generated by the fluorescent polymer reaches the maximum, and the equivalent diameter of the light spot in the light spot image also reaches the maximum. The laser focus continues to move until it is completely within the fluorescent polymer, and the spot size in the spot image no longer changes.

S222: judging whether the size of the light spot is increased or not, and making the following decision: and if the light spot is gradually reduced, reversely moving the substrate to enlarge the size of the light spot in the light spot image. And if the light spot is gradually enlarged, controlling the substrate to continuously move along the original direction until the size of the light spot is kept unchanged. If the light spot is kept unchanged, the equivalent diameter of the light spot reaches the maximum, the minimum circumscribed circle of the light spot is obtained, and the diameter of the minimum circumscribed circle is the reference value.

The laser focus can be moved to just above the interface between the substrate and the fluorescent polymer by moving the substrate according to the change in the fluorescent effect produced by the spot in the substrate and the fluorescent polymer. And (4) taking any one light spot image after the size of the light spot is not changed any more, wherein the minimum external circle on the light spot is the equivalent diameter of the light spot. In this embodiment, the maximum equivalent diameter of the spot is taken as a reference value.

S23: and calculating an ideal value of the equivalent diameter of the light spot according to the physical characteristics of the fluorescent polymer and the reference value.

Please refer to fig. 10, which is a schematic diagram illustrating the sizes of the fluorescent light spots when the laser focuses are located at different positions in fig. 3. Wherein, fig. 10.a is a schematic diagram of a spot image when a laser focus is located in a substrate; FIG. 10.b is a schematic of the image of the spot when the laser focus begins to contact the fluorescent polymer; FIG. 10.c is a schematic illustration of a spot image with the laser focus located at the interface of the substrate and the fluorescent polymer; fig. 10.D is a schematic diagram of the spot image when the laser focus is in the ideal position. Since the physical properties of fluorescent polymers vary, the ideal processing location actually selected is not located exactly on the interface. Taking the photoresist as an example, when the equivalent diameter of the fluorescent light spot in the light spot image reaches 2/3 of the reference value, the laser focus is exactly located at the ideal processing position. I.e. 2/3 of the reference value is the ideal value of the equivalent diameter of the light spot.

S24: the height of the substrate is adjusted until the equivalent diameter of the spot in the spot image is equal to the desired value.

The size of the laser focus is small, and is only 0.5-2 μm. It is difficult to accurately focus even when observed under an objective lens. Through the fluorescence effect of the fluorescent polymer, the laser focus is focused and converted into image processing, the focusing accuracy is effectively improved, meanwhile, the image recognition efficiency is higher than the human eye observation efficiency, the eyes can be prevented from being injured, and the focusing safety is improved.

S3: and controlling the substrate to move to the next processing point according to the preset moving path. Judging whether the equivalent diameter of the light spot in the light spot image is equal to an ideal value or not, and making a decision as follows:

(1) Laser machining is performed directly at that location. When the equivalent diameter of the facula in the facula image is equal to an ideal value, focusing is finished at the processing point, and laser processing can be directly carried out according to the processing strategy.

(2) Otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished. In the laser processing process, after any processing point finishes laser processing, the substrate only moves in the horizontal direction, and the actual processing position needs to be confirmed by continuing focusing because the inclined direction of the substrate and the horizontal plane form an included angle and the height of the substrate changes after the processing is finished.

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

S4: and judging whether the machining is finished or not, and if the machining is not finished, repeating the step S3 until the machining is finished. And if the processing is finished, developing the processed micro-nano structure to obtain a finished product micro-nano structure.

Because the design structure is a three-dimensional micro-nano structure, the fluorescent polymer needs to be processed at multiple points on the substrate. Whether machining is finished or not can be judged according to the design structure and the finished machining position. After the micro-nano structure is processed, the micro-nano structure needs to be developed, and a part of the micro-nano structure exceeding the designed structure is removed to obtain a finished product micro-nano structure.

The two-photon automatic processing method for the non-flat substrate provided by the embodiment adopts the methods of point-division focusing and fluorescence focusing, and confirms whether the focusing is finished according to the equivalent diameter of the light spot by converting the focusing of the laser focus into the fluorescence image recognition, so that the focusing efficiency and the focusing accuracy are effectively improved. In addition, the problems that manual focusing operation is complicated, time is consumed and large errors exist in the process of processing on a non-flat substrate by using laser are solved by automatically focusing each processing point. In order to realize two-photon automatic processing for a non-flat substrate, the present embodiment also provides a two-photon automatic processing system for a non-flat substrate. The processing system comprises an imaging module, an image processing module, a decision-making module and a displacement control module.

The imaging module is used for acquiring a light spot image containing the fluorescent polymer and the scattered fluorescence thereof in real time. The fluorescent polymer generates a fluorescent effect under the irradiation of a laser focus, and an image containing the fluorescent polymer and the scattered fluorescence thereof is obtained by shooting the substrate and the fluorescent polymer in real time. And the light spot image acquired by the imaging module is transmitted to the image processing module.

The image processing module is used for preprocessing the light spot image and calculating the equivalent diameter of the light spot in the light spot image. The preprocessing of the light spot image comprises normalization processing and filtering processing. The normalization processing can convert each light spot image into the same form, the same standard is kept in the process of multiple times of processing, and the processing precision is improved. The filtering processing can inhibit the noise of the image on the premise of keeping the detail characteristics of the image, and the accuracy of the image processing is improved. The equivalent diameter of the light spot can be obtained through an image recognition model. If a color threshold value method is adopted to convert the color space of the image into an HSV color space, and then the light spots are extracted according to the color threshold value. And then, adding a minimum circumscribed circle on the light spot by adopting a pattern recognition model, and acquiring the diameter of the circumscribed circle as the equivalent diameter of the light spot.

The decision module is to: 1. and judging whether the equivalent diameter of the light spot is the maximum value or not, and if so, recording the maximum value of the equivalent diameter as a reference value.

The change relation between the equivalent diameter of the fluorescent light 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, and therefore, no fluorescent spot exists in the spot image. When the laser focus moves from the substrate to the fluorescent polymer until it contacts the fluorescent polymer, the fluorescent polymer produces a fluorescent effect and a fluorescent spot begins to appear in the spot image. When the laser focus continuously moves to the fluorescent polymer until the center of the laser focus is just positioned at the interface of the substrate and the fluorescent polymer, the fluorescent effect generated by the fluorescent polymer reaches the maximum, and the equivalent diameter of the light spot in the light spot image also reaches the maximum. The laser focus continues to move until it is completely within the fluorescent polymer, and the spot size in the spot image no longer changes.

It follows that when the equivalent diameter of the fluorescent spot is maximized, the laser focus is located just above the interface between the substrate and the fluorescent polymer. The interface of the substrate and the fluorescent polymer is the processing datum plane.

2. And judging whether the equivalent diameter of the light spot is an ideal value or not, and if so, confirming that the focusing is finished.

Since the physical properties of fluorescent polymers vary, the ideal processing location actually selected is not located exactly on the interface. Taking the photoresist as an example, when the equivalent diameter of the fluorescent light spot in the light spot image reaches 2/3 of the reference value, the laser focus is exactly located at the ideal processing position. I.e. 2/3 of the reference value is the ideal value of the equivalent diameter of the light spot.

The displacement control module is used for: and I, outputting a displacement signal according to a preset moving path, and further controlling the moving table to drive the substrate to horizontally move. In the laser processing process, a plurality of processing points are required to be arranged, and laser processing is performed at each processing point. In order to ensure that the processed three-dimensional micro-nano structure conforms to the designed structure as much as possible, a horizontal moving mode is adopted to position a processing point on the substrate.

And II, outputting a displacement signal according to a preset processing strategy, and further controlling the motion table to drive the substrate to move in a three-dimensional manner. At any processing point, the moving path of the laser focus is different according to the design structure. The processing of the three-dimensional micro-nano structure requires movement in at least three degrees of freedom.

And III, outputting a lifting signal during focusing, and controlling the moving platform to drive the substrate to lift. For any processing point, after finding the horizontal position of the processing point, focusing is completed only by lifting the substrate. The focusing method comprises the following steps: and acquiring a fluorescent polymer and a light spot image of the fluorescent polymer scattered by the fluorescent polymer, and adjusting the height of the substrate until the equivalent diameter of the light spot in the light spot image is equal to an ideal value.

The method of focusing may further include, for any of the machining points: and adjusting the height of the substrate to enable the laser focus to be just positioned on an interface of the substrate and the fluorescent polymer, namely the equivalent diameter of the light spot in the light spot image is just increased to a reference value or just reduced from the reference value, and the equivalent diameter of the light spot in the light spot image is moved upwards or downwards by a preset distance to enable the equivalent diameter of the light spot in the light spot image to be equal to an ideal value. The upward or downward movement of the substrate during focusing can be determined based on the relative position of the substrate and the fluorescent polymer. If the substrate is positioned below the fluorescent polymer, when the equivalent diameter of the light spot in the light spot image is equal to the reference value, the substrate is moved upwards to enable the laser focus to move towards the substrate, the equivalent diameter of the light spot in the light spot image is gradually reduced, and the distance from the reference surface to the ideal processing surface is recorded. Then, after the laser focus reaches the reference surface, the substrate is moved downwards by a corresponding distance.

Please refer to fig. 12, which is a schematic diagram of a laser path of the two-photon automatic processing apparatus for a non-flat substrate using the two-photon automatic processing method for a non-flat substrate in fig. 3. In this embodiment, the two-photon direct writing processing equipment is optimized according to the two-photon automatic processing method and system for the non-flat substrate, so as to obtain the two-photon automatic processing equipment for the non-flat substrate. The processing equipment comprises a laser, a motion table, a substrate, an optical path regulator, an objective lens, an imaging device and a controller.

The laser is used for emitting laser light. The present embodiment employs a femtosecond laser. The femtosecond laser is a laser produced by Coherent company and having a model of ChameleonVision-S, the output wavelength adjusting 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 for laser two-photon processing is 800nm. Of course, in other embodiments, the laser may also be a pulse laser or a continuous laser, as long as the laser can emit the laser light required for laser processing.

The substrate is used for bearing the fluorescent polymer, so that the fluorescent polymer is positioned on a laser path, and the fluorescent polymer generates a fluorescent effect when being irradiated by laser. In the embodiment, PDMS is used as a flexible non-flat substrate, a fluorescent polymer is dripped on the flexible substrate, and under the action of laser, PDMS generates light spots which are obviously different from the fluorescent polymer. Of course, in other embodiments, the substrate may be a transparent material such as a plastic sheet, so that the laser can irradiate the fluorescent polymer through the substrate. In this embodiment, the fluorescent polymer is a photoresist (SZ 2080), and the photoresist has a fluorescent effect. Before processing, the photoresist was placed on a glass slide and baked using a hot oven at 60 ° for 15 minutes. Of course, in other embodiments, the fluorescent polymer may also be made of other photosensitive materials having a fluorescent effect or doped with a fluorescent effect substance, such as photosensitive resin and photosensitive hydrogel, as long as the fluorescent polymer is three-dimensionally formed into a designed structure after laser processing and development. Of course, when other fluorescent polymers are selected, the ratio of the ideal value of the equivalent diameter of the light spot in the light spot image to the reference value is changed, and the ratio is set according to the physical characteristics of the adopted fluorescent polymers.

The motion platform is fixedly connected with the substrate and used for driving the substrate to move. The substrate can be fixedly connected with the motion table through methods such as magnetic attraction and the like so as to ensure that the substrate cannot deviate when the motion table drives the substrate to move. In this embodiment, a PI-E545 nm motion stage is used, which can drive the substrate to move in three directions, x, y, and z. The PI-E545 nanometer motion platform is electrically connected to the controller, and the motion of the PI-E545 nanometer motion platform is controlled by the controller. In the laser processing process, the substrate deflects different angles around an x axis and a y axis respectively, so that the scanning of a laser focus in an xy plane can be realized, and the height of the substrate can be directly adjusted through lifting movement in the z axis direction. Of course, in other embodiments, other micro-scale or nano-scale motion stages may be used, as long as precise movement of the substrate in three-dimensional space is achieved.

The light path regulator is arranged on the emission path of the laser and is used for regulating the intensity and the direction of the laser so as to enable the laser to be used for processing or focusing respectively. The light path regulator comprises a light gate and a pre-regulator spectroscope. The pre-regulator is arranged on a laser emission path of the laser and is used for regulating the energy and the phase of the laser.

The front regulator comprises a Glan Taylor prism, a half-wave plate, a beam expander, a reflector and an attenuation plate which are sequentially arranged along a laser emission path. The glan-taylor prism is used to control the energy of the laser beam. The Glan-Taylor prism is arranged on the emission path of the laser and used for converting the laser into polarized light. The Glan Taylor prism is a birefringent polarizing device made of natural calcite crystal, and the main component is CaCO ₃ The rhombohedral crystal of (1). An unbiased collimated laser beam is input to the glantree prism, and a linearly polarized light beam (e-light) can be obtained. The transmittance and polarization purity of the glantylor prism are higher than those of other polarizing plates. The half-wave plate is used for adjusting the phase of the laser beam. The half-wave plate is a birefringent crystal with a certain thickness, and when the normally incident light is transmitted, the phase difference between the ordinary light (o light) and the linearly polarized light (e light) is equal to pi or odd times of pi. The beam expander is used for increasing the diameter of the laser beam. The beam expander is a lens assembly capable of changing the diameter and divergence angle of the laser beam. The laser light emitted from the laser has a certain divergence angle, and the adjustment by the beam expander changes the laser beam into a collimated (parallel) laser beam. The reflecting mirror is used for adjusting the emission direction of the laser beam. The attenuation sheet is used for adjusting the energy of the laser beam. The light intensity can be attenuated by making the substance into sheet by using the absorption characteristic of the substance to the light and placing the sheet on the light path adjusting component, and the sheet element is called as an optical attenuation sheet. The amount of light passing through the attenuation sheet depends on the type of material and also on the thickness of the material.

The optical shutter is arranged between the laser and the front regulator and used for controlling the on-off of the laser.

The spectroscope is arranged on a laser emergent path of the prepositive regulator and used for reflecting the processed laser and transmitting the imaging light, and respectively enabling the reflected laser to enter the objective lens and the transmitted light to enter the imaging device. In this embodiment, the dichroic mirror is a dichroic mirror, and has the characteristics of reflecting infrared light with a wavelength of 750-850nm and transmitting visible light with a wavelength of 400-700 nm. Laser with the wavelength of 800nm emitted by the laser is reflected by the reflector and then vertically incident on the objective lens, and other visible light is directly transmitted, so that the influence on the processing or focusing process is avoided. In addition, the wavelength of the fluorescence emitted by the fluorescent polymer is generally between 450 and 600nm, and the fluorescence can also be directly transmitted from the spectroscope and captured by the camera, so that the definition of fluorescence imaging can be improved, and the interference of the fluorescence on laser processing can be avoided.

Of course, in other embodiments, the optical path adjusting assembly may be replaced by a light guiding element such as an optical fiber, as long as the light guiding element can convert the laser light into a collimated laser beam and vertically incident on the objective lens.

The objective lens is arranged on a laser emergent path of the optical path regulator and used for focusing laser. 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 may also be larger or smaller.

The imaging device is arranged on a fluorescent path scattered by the fluorescent polymer and is used for acquiring a light spot image containing the fluorescent polymer and the scattered fluorescence thereof in real time. The imaging device is also used for transmitting the acquired spot image to the controller. In this embodiment, the imaging device is a CCD camera. The CCD camera has the characteristics of small volume, light weight, no influence of a magnetic field and vibration and impact resistance. The image collected by the CCD camera has the characteristics of high definition and convenient transmission. Of course, in other embodiments, the imaging device may be replaced by a photoelectric conversion element such as a photodiode or a phototransistor, as long as the optical signal emitted from the substrate and the fluorescent polymer can be converted into an image or an electrical signal.

The controller is used for: 1. and controlling the motion platform to adjust the horizontal position of the substrate so that the horizontal position of the laser focus is positioned in the initial processing area of the substrate. In the laser processing process, the controller firstly generates a scanning strategy according to the designed micro-nano structure. The scanning strategy includes a horizontal moving path formed on the basis of a plurality of processing points and a processing strategy generated at each processing point. And then, moving the substrate to enable the horizontal position of the laser focus to be located in a preset initial processing area, thereby avoiding the processed micro-nano structure from exceeding the surface of the substrate to cause structure loss.

2. And focusing the laser emitted by the laser so as to enable the substrate to be positioned at the ideal initial processing position, and carrying out laser processing at the initial processing position according to the corresponding processing strategy. After the laser focus is located within the initial processing region, the substrate needs to be moved to the desired processing position to avoid partial or complete loss of the processing structure. The focusing method comprises the following steps: and acquiring a fluorescent polymer and a light spot image of the fluorescent polymer scattered by the fluorescent polymer, and adjusting the height of the substrate until the equivalent diameter of the light spot in the light spot image is equal to an ideal value.

3. And controlling the motion table to drive the substrate to move according to a preset moving path, and further finishing corresponding laser processing on each processing point. And laser focusing is carried out at each processing point, so that the influence of substrate unevenness on laser processing is reduced or eliminated, and the accuracy of laser processing is improved.

4. And judging whether the equivalent diameter of the light spot in the light spot image is equal to an ideal value or not, and if so, directly carrying out laser processing at the position. Otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished. Because the design structure is a three-dimensional micro-nano structure, the fluorescent polymer needs to be processed at multiple points on the substrate. Whether the machining is finished or not can be judged according to the design structure and the finished machining position. After the micro-nano structure is processed, the micro-nano structure needs to be developed, and a part of the micro-nano structure exceeding the designed structure is removed, so that a finished product micro-nano structure is obtained.

The two-photon automatic processing equipment for the non-flat substrate provided by the embodiment can confirm whether the focusing is finished or not according to the equivalent diameter of the light spot by converting the focusing of the laser focus into the fluorescent image recognition, thereby effectively improving the focusing efficiency and the focusing accuracy. In addition, the problems that manual focusing operation is complicated, time is consumed and large errors exist in the process of processing on a non-flat substrate by using laser are solved by automatically focusing each processing point.

Experimental verification

Experiment one: and when the laser focus is positioned at different positions, observing the change relation between the processed micro-nano structure and the designed structure.

A substrate with an inclined surface is adopted, and the substrate is fixedly connected with a moving table. The laser wavelength emitted by the laser is adjusted to 800nm by the optical path adjuster, array processing is performed in one horizontal direction, all processing points are kept on the same horizontal plane, and the structural color of the obtained microcolumn is as shown in fig. 13. Subsequently, focusing was performed on each processing point while keeping the substrate and the laser wavelength constant, and the resulting microcolumn structural color was as shown in fig. 14.

Referring to fig. 13 and 14, fig. 13 is a diagram of structural colors and micropillar arrays caused by the relative height of the laser focus and the substrate surface being different; FIG. 14 is a diagram of fluorescent color and microcolumn arrays achieved after using auto-focus. It can be seen that, when each processing point is not focused, although the laser focus is maintained on the same horizontal plane, the relative height of the laser focus and the substrate is changed due to the inclination of the substrate surface, and the height of the microcolumn processed at the first processing point is different from the height of the microcolumn processed at the last processing point (the 6 th processing point) by 1.5 μm on the processing path with the total length of 50 μm, and the scattered fluorescent color of each microcolumn is green, blue, red, orange, yellow and yellow in turn.

According to the experimental results, the analysis is carried out because the uneven substrate can cause the situation that the heights of the processed micro-column arrays are inconsistent. Among them, the reason why the microcolumns of different structural colors are generated is: the substrate unevenness causes the processing height to be inconsistent, and further causes the height of the processed microstructure to be different, thereby causing structural color change. The reason why the heights of the microcolumns are different is: the relative positions of the laser focus and the substrate surface are different, so that the actual processing structure is inconsistent with the design structure parameters.

As can be seen in fig. 14, the height of the processed microcolumns is uniform by using auto-focusing, and the structural color of each microcolumn is also red. In this experiment, the non-flatness error or inclination of the experimental platform processing substrate is in 1:50 to 1: between 25, the influence on the micro-nano structure is relatively large. Thus, non-planar substrate effects are corrected by the present method. When the initial position is positioned to the ideal processing position, the size of the fluorescence spot at the time is recorded, the size of the fluorescence spot generated in the subsequent processing array is compared with the initial position, and when the size of the fluorescence spot is inconsistent, the rotating mirror stage is controlled to move until the size of the current fluorescence spot is the same as that of the fluorescence spot at the initial position. After the two-photon direct writing processing process based on the fluorescence effect is used for automatically focusing the non-flat substrate, the processed micro-column arrays have consistent height, and the influence of the change of the non-flat substrate on the processing structure can be reduced.

Experiment two: and processing the micro-nano structure on the patterned substrate by using an automatic focusing method and without using the automatic focusing method.

Please refer to fig. 15, which is a comparison diagram of an experiment for processing micro/nano structures at different positions on a patterned substrate. Fig. 15a is a schematic structural diagram of a patterned substrate; FIG. 15b is a diagram illustrating the effect of fabricating a micro-nano array on a patterned substrate without using an automated fabrication process; and FIG. 15c is a diagram of the effect of processing a micro-nano array on a patterned substrate by adjusting the focus position. Using a patterned substrate as shown in fig. 15a, the patterned substrate can be obtained using a lithographic process. The specific process is to spin a layer of SU-8 photoresist 50 microns thick on a glass slide and expose the patterned photoresist using a photolithography machine (model: ABM 6350). After exposure, a developing solution is used for removing the redundant part, and a groove structure with the designed width is formed on the surface of the glass slide by the photoresist structure. In the experiment, the depth of the groove is 50 microns, and the width is 80-150 microns.

And (3) dropwise adding SZ2080 photoresist on the patterned substrate, and pre-baking for 30min at 100 ℃. And fixedly connecting the substrate with the motion table, adjusting the laser wavelength emitted by the femtosecond laser to 800nm through the light path adjuster, and then performing array processing.

As can be seen from fig. 15b and 15c, when each processing point is not automatically processed, the laser focus is maintained at the same horizontal plane, but the processed substrate is in a trench structure, and the height of the processed micropillars is obviously different from that of the micropillars at the bottom of the trench due to the change of the substrate height in the transition region between the bottom and the side wall of the trench. Resulting in the collapse and deformation of the processed micro-column, and poor processing effect. By using the focus adjusting method, the heights of the processed micro-column arrays are consistent, and the overall processing effect is good without collapse and deformation.

Therefore, the automatic processing method can correct the influence of the non-planar substrate on processing, and realize the complete three-dimensional micro-nano structure array on the non-planar substrate.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1.A two-photon automatic processing method for a non-flat substrate is characterized by comprising the following processes:

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; the initial processing area is characterized in that when an optional point in the area is used as an initial processing point, the horizontal areas where the designed structures are located are all located on the substrate;

s2: focusing laser to enable the substrate to be located at an ideal initial processing position, and performing laser processing at the initial processing position according to a corresponding processing strategy; the focusing method comprises the following steps:

s21: taking the fluorescent polymer as a viewing object, and collecting a light spot image of fluorescent polymer scattered fluorescence in real time;

s22: adjusting the height of the substrate, and calculating 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 the maximum value;

s23: calculating an ideal value of the equivalent diameter of the light spot according to the physical characteristics of the fluorescent polymer and the reference value;

s24: adjusting the height of the substrate until the equivalent diameter of the light spot in the light spot image is equal to an ideal value;

s3: controlling the substrate to move to the next processing point according to a preset moving path; judging whether the equivalent diameter of the light spot in the light spot image is equal to an ideal value or not, and making a decision as follows:

(1) If so, directly carrying out laser processing at the position;

(2) Otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished;

s4: judging whether the machining is finished or not, if not, repeating S3 until the machining is finished; and if the processing is finished, developing the processed micro-nano structure to obtain a finished product micro-nano structure.

2.A two-photon automated processing method for non-flat substrates according to claim 1, wherein in S1, the initial processing region is calculated according to the horizontal region covered by the substrate and the horizontal region covered by the scanning strategy, and the specific method is as follows:

a. the profile p of the substrate _j Profile p of laser focus _l Horizontal area p covered by the machining strategy _p And the horizontal area p covered by the scanning strategy _s Mapping on the same plane; p is to be _l And p _p Are concentrically arranged and are at p _j Inner edge p _p And p _j The tangent path moves for one circle; p is to be _l And p _j Is enclosed intoFrom p to _j Removing to obtain an intermediate profile p _m ；

b. To p _m Zooming is carried out until the zoomed graph is just externally connected with p _s The above step (1); let p _m Is n-polygonal and is externally connected with p _s Is a pattern of p _ms Then p will be _ms Are sequentially attached to corresponding p _m At each corner of (a); during each attaching, making extension lines on other n-2 sides which are not adjacent to the attached corners; multiple extension lines p _s Dividing the image into a plurality of subareas; will contain p therein _m As an initial machining area.

3. A two-photon automated processing method for non-flat substrates according to claim 1, wherein in S1, the method of judging that the focal point of the laser is located in the initial processing region is as follows:

s11: taking a substrate as a view finding object, and collecting a substrate image containing a laser focus;

s12: preprocessing a substrate image, and reserving the outer contour of the substrate and the outer contour of a laser focus;

s13: adding a contour line of an initial processing area in the outer contour of the substrate;

s14: observing whether the outer contour of the laser focus is completely positioned in the initial processing area, and if so, confirming that the laser focus is positioned in the initial processing area; otherwise, the substrate is moved until the outer contour of the laser focus is completely in the initial processing area.

4. A two-photon automated processing method for a non-flat substrate according to claim 1, wherein in S22, the reference value is obtained as follows:

s221: and observing whether the light spots exist in the initial light spot image, and making the following decision: if no light spot exists, lifting the substrate until the light spot appears in the light spot image; if the light spots exist, the substrate is controlled to move upwards or downwards, and the size change of the light spots is observed;

s222: judging whether the size of the light spot is increased or not, and making the following decision: if the light spot is gradually reduced, the substrate is reversely moved, so that the size of the light spot in the light spot image is increased; if the light spot is gradually enlarged, controlling the substrate to continuously move along the original direction until the size of the light spot is kept unchanged; if the light spot is kept unchanged, the equivalent diameter of the light spot reaches the maximum, the minimum circumscribed circle of the light spot is obtained, and the diameter of the minimum circumscribed circle is the reference value.

5. A two-photon automated processing method for a non-flat substrate according to claim 1, wherein in S3, the movement of the substrate is a three-dimensional movement with an initial processing point as an origin, a vertical direction as a Z-axis, any horizontal direction as an X-axis, and another horizontal direction perpendicular to the X-axis as a Y-axis; the movement path only includes the movement of the substrate in the X-axis and the Y-axis; the focusing process only includes movement of the substrate in the Z-axis.

6. A two-photon automated processing system for non-flat substrates, which employs the two-photon automated processing method for non-flat substrates according to any one of claims 1 to 5, comprising:

the imaging module is used for acquiring a light spot image containing a fluorescent polymer and scattered fluorescence thereof in real time;

the image processing module is used for preprocessing the light spot image and calculating the equivalent diameter of the light spot in the light spot image;

a decision module to: 1. judging whether the equivalent diameter of the light spot is the maximum value or not, 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 or not, and if so, confirming that focusing is finished;

a displacement control module to: i, outputting a displacement signal according to a preset moving path, and further controlling a moving table to drive a substrate to horizontally move; II, outputting a displacement signal according to a preset processing strategy, and further controlling the motion platform to drive the substrate to move in three dimensions; and III, outputting a lifting signal during focusing, and controlling the moving platform to drive the substrate to lift.

7. A two-photon automatic processing device for a non-flat substrate is used for processing a fluorescent polymer to be processed into a corresponding three-dimensional micro-nano structure according to a design structure; which employs the two-photon automated processing method for non-flat substrates according to any one of claims 1 to 5; the processing equipment comprises a laser, a motion table and a substrate; the laser is used for emitting laser; the substrate is used for bearing the fluorescent polymer so that the fluorescent polymer is positioned on a laser path and generates a fluorescent effect when being irradiated by laser; the motion table is fixedly connected with the substrate and used for driving the substrate to move; characterized in that, the processing equipment still includes:

the light path regulator is arranged on the emission path of the laser and is used for regulating the intensity and the direction of the laser so as to enable the laser to be respectively used for processing or focusing;

an objective lens disposed on a laser exit path of the optical path adjuster, for focusing the laser light;

the imaging device is arranged on a fluorescent path scattered by the fluorescent polymer and is used for acquiring a light spot image containing the fluorescent polymer and the scattered fluorescence thereof in real time; and

a controller to: 1. controlling the motion table to adjust the horizontal position of the substrate, so that the horizontal position of the laser focus is positioned in the initial processing area of the substrate; 2. focusing laser emitted by the laser so as to enable the substrate to be positioned at an ideal initial processing position, and performing laser processing at the initial processing position according to a corresponding processing strategy; 3. controlling the motion table to drive the substrate to move according to a preset moving path, and further finishing corresponding laser processing on each processing point; 4. judging whether the equivalent diameter of the light spot in the light spot image is equal to an ideal value or not, and if so, directly carrying out laser processing at the position; otherwise, focusing is carried out at the processing point, and laser processing is carried out at the processing point after focusing is finished.

8. A two-photon automated processing apparatus for non-flat substrates according to claim 7, wherein the optical path modulator comprises a shutter, a pre-modulator and a beam splitter; the preposed regulator is arranged on a laser emission path of the laser and is used for regulating the energy and the phase of the laser; the optical shutter is arranged between the laser and the preposed regulator and used for controlling the on-off of the laser; the spectroscope is arranged on a laser emergent path of the prepositive regulator, and is used for reflecting incident laser for micro-nano processing into the objective lens and transmitting an image and a fluorescence signal of a processing position into the imaging device through the spectroscope.

9. A two-photon automated processing apparatus for non-planar substrates according to claim 8, wherein the pre-conditioner comprises a glan-taylor prism, a half-wave plate, a beam expander, a mirror, and an attenuation plate disposed in sequence along the laser emission path; the Glan Taylor prism is used for controlling the energy of the laser beam; the half-wave plate is used for adjusting the phase of the laser beam; the beam expander is used for adjusting the diameter of the laser beam; the reflector is used for adjusting the emission direction of the laser beam; the attenuation sheet is used for adjusting the energy of the laser beam.

10.A two-photon automated processing apparatus for non-planar substrates according to claim 7, wherein the laser is a femtosecond laser; the imaging device is a CCD camera; the motion platform is a three-dimensional micro-nano motion platform.

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