CN112171065A

CN112171065A - Laser polishing system and method

Info

Publication number: CN112171065A
Application number: CN202011192261.XA
Authority: CN
Inventors: 徐少林; 李铁; 郭杨; 邱佩
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology; Southern University of Science and Technology
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2021-01-05

Abstract

The application belongs to the technical field of laser polishing and provides a laser polishing system and a method, wherein the system comprises: the device comprises a laser polarization fixing module, a time domain shaping module, a light field regulating and controlling module and a control device; the laser polarization fixing module converts laser emitted by the laser light source into a laser beam with a fixed polarization direction; the control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delay beam with preset delay and preset energy ratio; the light field regulation and control module regulates the double-pulse delay light beam into a light field distributed in a linear mode and irradiates the light field to the surface of an object to be polished. The embodiment of the application solves the problems of low laser polishing efficiency and poor polishing quality.

Description

Laser polishing system and method

Technical Field

The invention relates to the technical field of laser polishing, in particular to a laser polishing system and a laser polishing method.

Background

In the field of manufacturing, polishing is a surface modification process that is extremely important for workpieces. The principle of laser polishing is that a surface layer material is evaporated and melted under the action of laser, the melted material flows under the action of surface tension and gravity, the concave part of the original rough surface is filled, and the melted surface layer material is cooled and solidified to form an ideal smooth surface. The laser polishing has the advantage of easily realizing surface polishing on a complex geometric profile, and meanwhile, the polished surface does not introduce chemical pollution, no waste is generated in the polishing process, and green manufacturing can be realized. At present, the femtosecond laser with extremely small heat effect is adopted to polish the material, the femtosecond laser pulse duration is extremely short, the heat damage of the sub-surface can be avoided, and the method is an effective cold machining polishing method.

However, femtosecond laser polishing mainly has two problems: firstly, the polishing efficiency is low, and the high-efficiency scanning polishing cannot be realized due to the limitation of Gaussian light field distribution; in addition, the generation of the ultrafast Laser Induced Periodic Surface Structures (Laser Induced Periodic Surface Structures) increases Surface roughness and reduces the quality of the polished Surface.

Disclosure of Invention

In view of this, embodiments of the present invention provide a laser polishing system and method to solve the problems of low polishing efficiency and poor polishing quality of laser.

A first aspect of an embodiment of the present invention provides a laser polishing system, including: the device comprises a laser polarization fixing module, a time domain shaping module, a light field regulating and controlling module and a control device;

the laser polarization fixing module converts laser emitted by the laser light source into a laser beam with a fixed polarization direction;

the control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delay beam with preset delay and preset energy ratio;

the light field regulation and control module regulates the double-pulse delay light beam into a light field distributed in a linear mode and irradiates the light field to the surface of an object to be polished.

In one implementation example, the time domain shaping module comprises a first beam splitting device, a second beam splitting device, a first attenuation device, a second attenuation device and a displacement table provided with a mirror group;

the first beam splitting device splits the laser beam into reference light and delayed light, the emergent direction of the reference light is the input direction of the first attenuation device, and the emergent direction of the delayed light is intersected with the reflecting plane of the reflector group;

the first attenuation device attenuates the energy of the reference light, and the reference light after energy attenuation is incident to the second beam splitting device;

the reflector group reflects the delayed light to the second beam splitting device;

the second attenuation device is arranged in a light path of the second beam splitting device for reflecting the delayed light by the reflector group, and energy attenuation is carried out on the delayed light.

In an embodiment, the controlling device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delayed beam with a preset delay and a preset energy ratio, and includes:

the control device controls the displacement table to move according to the preset delay, and changes the optical path difference between the delay light and the reference light so that the delay light has the preset delay;

the control device controls the first attenuation device or the second attenuation device to rotate according to a preset energy ratio, so that the energy ratio between the reference light subjected to energy attenuation and the delayed light subjected to energy attenuation by the second attenuation device is the preset energy ratio;

and the second beam splitting device combines the incident light beams to obtain the double-pulse delay light beam.

In one implementation example, the first beam splitting device and the second beam splitting device are both half-wave plates; the first attenuation device and the second attenuation device are both neutral density attenuation sheets;

the reflector group comprises a first reflector and a second reflector; the delayed light reflected to the second beam splitting device by the first mirror and the second mirror and the reference light incident to the second beam splitting device generate an interference grating.

In one implementation example, the system further comprises an expanded beam collimation module;

the beam expanding and collimating module performs beam expanding processing and beam collimating adjustment on the double-pulse delayed light beam output by the time domain shaping module, and emits the adjusted double-pulse delayed light beam to the light field regulating and controlling module.

In one implementation example, the beam expanding and collimating module comprises a first lens and a second lens which are sequentially arranged along an optical path;

the first lens carries out beam expanding processing on the double-pulse delay light beam output by the time domain shaping module, and the light beam after beam expanding processing is incident to the second lens;

the second lens is used for carrying out light beam collimation adjustment on the light beam after beam expansion treatment and transmitting the adjusted double-pulse delay light beam to the light field regulation and control module;

the first lens is a concave lens; the second lens is a convex lens.

In one embodiment, the system further comprises an article displacement table for placing the object to be polished and a photographing device;

the control device controls the shooting device to shoot the surface of the object to be polished to obtain a surface image;

and the control device controls the article displacement table to move according to the surface image so that the light field scans and polishes the surface of the object to be polished.

In one implementation example, the system further comprises a laser light source; the control device controls the laser light source to emit laser.

In one implementation example, the laser polarization fixing module comprises a first wave plate and a polarization beam splitter which are sequentially arranged along an optical path;

laser emitted by the laser source is converted into a laser beam with a fixed polarization direction through the first wave plate and the polarization beam splitter in sequence;

the first wave plate is a half-wave plate; the polarizing beam splitter is a Glan prism.

In one implementation example, the light field regulation and control module comprises a cylindrical plano-convex lens and a focusing objective lens which are sequentially arranged along an optical path;

the cylindrical plano-convex lens adjusts the double-pulse delay light beam into a light field distributed in a linear mode, and the light field is irradiated to the surface of an object to be polished through the focusing objective lens.

A second aspect of an embodiment of the present invention provides a laser polishing method applied to the laser polishing system of the first aspect;

the laser polishing method includes the following operations performed by a control device:

controlling the displacement table to move according to the preset delay, and changing the optical path difference between the delayed light and the reference light so that the delayed light has the preset delay;

and controlling the first attenuation device or the second attenuation device to rotate according to a preset energy ratio so that the energy ratio between the reference light for energy attenuation and the delayed light for energy attenuation by the second attenuation device is the preset energy ratio, and enabling the second beam splitting device to combine incident light beams to obtain the double-pulse delayed light beams.

In the laser polishing system and method provided by the embodiment of the invention, the laser polarization fixing module converts laser emitted by the laser light source into a laser beam with a fixed polarization direction; the laser polarization fixing module is used for converting laser emitted by the laser light source into linearly polarized light with a fixed polarization direction. The control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delay beam with preset delay and preset energy ratio; the control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam, so that the surface quality of the laser beam after the laser beam acts on an object to be polished is improved; the obtained double-pulse delay light beam with the preset delay and the preset energy ratio can effectively eliminate the generation of an ultrafast laser-induced surface periodic micro-nano structure on the surface of the object to be polished, so that the surface roughness of the object to be polished is reduced after the surface of the object to be polished is polished by the double-pulse delay light beam, and the object polishing quality of laser is improved. The light field regulation and control module regulates the double-pulse delay light beam into a light field distributed in a linear mode and irradiates the light field to the surface of an object to be polished. The double-pulse delay light beam is adjusted to be a linear distributed light field through the light field regulation and control module, the utilization rate of the double-pulse delay light beam is improved, single scanning can act on a larger area to be polished, and the polishing efficiency of laser is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of a laser polishing system according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of controlling, by the control device, the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam according to the first embodiment of the present invention;

fig. 3 is a schematic structural diagram of a time domain shaping module according to an embodiment of the present invention for performing beam splitting delay adjustment and control on the laser beam;

fig. 4 is a schematic structural diagram of a control device according to a second embodiment of the present invention;

the reference numbers are: 10-a laser polarization fixing module; 20-a time domain shaping module; 30-a light field modulation module 30; 40-a control device; 50-a laser light source; 60-a beam expanding collimation module; 70-an article displacement table; 80-a camera; 11-a first wave plate; 12-a polarizing beam splitter; 13-a stopper; 21-first beam splitting means; 22-second beam splitting means; 23-first attenuating means; 24-a second attenuating device; 25-a mirror group; 26-a displacement table; 251-a first mirror; 252-a second mirror; 31-cylindrical plano-convex lens; 32-a focusing objective lens; 61-a first lens; 62-a second lens; 81-dichroic mirror.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all 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.

The terms "comprises" and "comprising," and any variations thereof, in the description and claims of this invention and the above-described drawings are intended to cover non-exclusive inclusions. For example, a process, method, or system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," and "third," etc. are used to distinguish between different objects and are not used to describe a particular order.

Example one

Fig. 1 is a schematic structural diagram of a laser polishing system according to an embodiment of the present invention. The laser polishing system includes: the device comprises a laser polarization fixing module 10, a time domain shaping module 20, a light field regulating and controlling module 30 and a control device 40;

the laser polarization fixing module 10 converts laser light emitted from a laser light source into a laser beam with a fixed polarization direction. The laser polarization fixing module 10 converts the laser emitted from the laser source into a linear polarization laser beam with a fixed polarization direction.

In one implementation example, the laser polarization fixing module 10 includes a first wave plate 11 and a polarization beam splitter 12, which are sequentially disposed along an optical path; the laser light emitted by the laser light source is converted into a laser beam with a fixed polarization direction through the first wave plate 11 and the polarization beam splitter 12 in sequence.

Specifically, the laser polarization fixing module 10 may include a first wave plate 11 and a polarization beam splitter 12. The laser incident to the laser polarization fixing module 10 is converted into a laser beam with a fixed polarization direction through the first wave plate 11 and the polarization beam splitter 12; meanwhile, the combination of the first wave plate 11 and the polarization beam splitter 12 also plays a role in power adjustment, so that the power of the laser beam emitted by the laser polarization fixing module 10 is controlled within a reasonable range. Optionally, the first wave plate 11 is a half-wave plate; the polarizing beam splitter 12 is a glan prism. When laser light incident to the laser polarization fixing module 10 is incident to the glan prism through the first wave plate 11, the glan prism decomposes the incident laser light into stray light and a laser beam with a fixed polarization direction, the laser beam with the fixed polarization direction is incident to the time domain shaping module 20, and the other stray light is blocked by a block 13 included in the laser polarization fixing module 10.

In one example, the laser polishing system further includes a laser light source 50; the control device 40 controls the laser light source 50 to emit laser light.

Specifically, the laser polishing system further includes a laser light source 50. When a user polishes an object to be polished by using the laser polishing system, the laser light source can be controlled to emit laser by the control device, so that the laser polishing starting time can be controlled. Optionally, the laser light source may be a femtosecond laser with a center wavelength of 520nm and a pulse width of 300fs, and the generated laser is a linearly polarized gaussian laser beam. In the laser polishing process, the control device controls the laser light source to emit laser with the pulse energy of 0.11 muJ, the beam diameter of 2mm, the laser repetition frequency of 1kHz and the scanning speed of 500 muM/s.

The laser beam converted into the laser beam with fixed polarization direction by the laser polarization fixing module 10 is incident to the time domain shaping module 20; the control device 40 controls the time domain shaping module 20 to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delay beam with a preset delay and a preset energy ratio;

specifically, the ultrafast laser-induced surface periodic wiener structure is generated when the laser is used for polishing the object to be polished, so that the roughness of the surface of the object is increased, and the polishing quality is reduced. In order to solve the problem, the control device 40 may control the time domain shaping module 20 to perform beam splitting delay regulation and energy regulation on the incident laser beam, so as to split the laser beam into a double-pulse delay beam including the reference light and the delay light with a preset delay and adjust the energy of the laser beam, so that a preset energy ratio is provided between the reference light and the delay light in the double-pulse delay beam. When the object to be polished is polished by the double-pulse delay beam with the preset delay and the preset energy ratio, the surface appearance of the object polished by the reference light can be effectively adjusted by the delay light with the preset delay in the double-pulse delay beam, so that the generation of the ultrafast laser-induced surface periodic micro-nano structure on the surface of the object to be polished is effectively eliminated, the roughness of the polished surface of the object to be polished is reduced after the surface of the object to be polished is polished by the double-pulse delay beam, and the polishing quality of the laser is improved.

In one embodiment, to implement beam splitting delay regulation and energy regulation on the incident laser beam, the time domain shaping module 20 includes a first beam splitting device 21, a second beam splitting device 22, a first attenuation device 23, a second attenuation device 24, and a displacement stage 26 provided with a mirror group 25;

the first beam splitting device 21 splits an incident laser beam into reference light and delayed light, an exit direction of the reference light is an input direction of the first attenuation device 23, and an exit direction of the delayed light intersects with a reflection plane of the mirror group 25; the first attenuation device 23 attenuates the energy of the reference light, and the reference light after energy attenuation is incident to the second beam splitting device 22; the reflecting mirror group 25 reflects the delayed light to the second beam splitting device; 22 and the second attenuation device 24 is disposed in the optical path where the mirror group 25 reflects the delayed light to the second beam splitting device 22, and attenuates the energy of the delayed light.

Specifically, the first beam splitting device 21 is disposed in the time domain shaping module 20, so that the incident laser beam can be split into two identical beams, one of which is used as the reference light, and the other is used as the delay light. In the internal optical path of the time domain shaping module 20, the emitting direction of the reference light is the input direction of the first attenuating device 23, the first attenuating device 23 attenuates the energy of the reference light, and the energy-attenuated reference light is incident to the second beam splitting device 22; the exit direction of the delayed light intersects with the reflection plane of the mirror group 25, and the mirror group 25 reflects the delayed light to the second beam splitting device; 22 and the second attenuation device 24 is disposed in the optical path where the mirror group 25 reflects the delayed light to the second beam splitting device 22, and attenuates the energy of the delayed light. Since the delayed light is reflected by the mirror group 25 and then enters the second beam splitting device 22, the delayed light has a section of optical path length greater than that of the reference light and is reflected by the mirror group 25. Therefore, the delayed light has a delay time as compared with the reference light, and the delay time of the delayed light can be adjusted to a predetermined delay time by increasing or shortening the optical path of the delayed light reflected by the mirror group 25, that is, by moving the displacement stage 26 provided with the mirror group 25. Optionally, the first beam splitting device and the second beam splitting device are both half-wave plates.

In one embodiment, the first and second attenuating devices are each a neutral density attenuating plate. The first attenuation device 23 and the second attenuation device 24 are attenuation devices capable of changing transmittance and further adjusting pulse energy by changing angles, power measurement is performed on the reference light attenuated by the first attenuation device 23 and the delayed light attenuated by the second attenuation device 24 by matching with a power meter, and the energy ratio between the reference light attenuated by the first attenuation device 23 and the delayed light attenuated by the second attenuation device 24 can be adjusted to be a preset energy ratio by rotating the first attenuation device 23 and the second attenuation device 24 to change the angles of the first attenuation device 23 and the second attenuation device 24.

In an implementation example, as shown in fig. 2, when the time domain shaping module 20 includes a first beam splitting device, a second beam splitting device, a first attenuation device, a second attenuation device, and a displacement stage provided with a mirror group, a specific process of controlling the time domain shaping module 20 to perform beam splitting delay regulation and energy regulation on the laser beam by the control device 30 includes steps 11 to 13:

step 11, the control device controls the displacement table to move according to the preset delay, and changes the optical path difference between the delayed light and the reference light so that the delayed light has the preset delay;

in order to realize the automatic control of the beam splitting delay regulation of the time domain shaping module 20 in the laser polishing system, the movement of the displacement table can be controlled by the control device so as to realize the delay regulation of the delay light without manual operation. The control device can shorten or increase the optical path of the delayed light reflected by the reflector group 25 by controlling the displacement table 26 to move up and down along the vertical direction so as to change the delay of the delayed light. In order to obtain the delayed light with the preset delay, the control device may control the displacement stage to move according to the preset delay, and change an optical path difference between the delayed light and the reference light, so that the delayed light has the preset delay.

In one embodiment, the mirror group 25 includes a first mirror 251 and a second mirror 252. The delayed light reflected 252 by the first mirror 251 and the second mirror to the second beam splitting device 22 generates an interference grating with the reference light incident to the second beam splitting device 22. Specifically, the two beams of light transmitted in the air form a grating due to interference when they are temporally and spatially overlapped. Before the time-domain shaping module 20 performs beam splitting delay control, in order to ensure that the reference light and the delay light after being split by the first beam splitter 21 can achieve time-space coincidence, the position of the displacement stage 26 provided with the first reflector 251 and the second reflector 252 when the delay light reflected 252 by the first reflector 251 and the second reflector 22 and the reference light incident to the second beam splitter 22 generate interference gratings needs to be determined as an initial state of the displacement stage. When the control device controls the displacement table to move up and down along the vertical direction under the condition of the initial state of the displacement table, the reference light and the delay light are always ensured to be overlapped in time and space.

In detail, as shown in fig. 3, in the initial state of the stage, the control device controls the stage 26 to move up and down in the vertical direction, so that the optical path length of the delayed light reflected by the mirror group 25 is reduced or increased by twice the delay arm offset distance Δ d. The delay delta t of the delay light can be obtained by calculation according to the ratio of the offset distance delta d of the double delay arm to the light speed c, and the formula is

Therefore, after the control device calculates the offset distance Δ d of the delay arm that needs to be moved in the initial state of the displacement table according to the preset delay, the control device controls the displacement table 26 to move the offset distance Δ d of the delay arm in the vertical direction in the initial state of the displacement table, so that the delay light has the preset delay. Optionally, when the preset delay is 20ps, the double-pulse delay beam with the preset delay and the preset energy ratio can significantly change the electron-phonon coupling process inside the material, macroscopically, the fluidity of the material is improved, and the polishing effect of the object to be polished is optimal; the delay arm is now offset by a distance Δ d of 3 mm.

Step 12, the control device controls the first attenuation device or the second attenuation device to rotate according to a preset energy ratio, so that the energy ratio between the reference light for energy attenuation and the delayed light for energy attenuation by the second attenuation device is the preset energy ratio;

since the first and second attenuators are both neutral density attenuators, the first attenuator 23 or the second attenuator 24 is an attenuator that can change the transmittance by changing the angle. In order to realize automatic control of energy adjustment of the time domain shaping module 20 in the laser polishing system, the power meter is matched to measure the power of the reference light attenuated by the first attenuation device 23 and the power of the delayed light attenuated by the second attenuation device 24, the control device is used for controlling the first attenuation device 23 or the second attenuation device 24 to rotate so as to change the angle of the first attenuation device 23 or the second attenuation device 24, and the energy ratio between the reference light attenuated by the first attenuation device 23 and the delayed light attenuated by the second attenuation device 24 can be adjusted to be a preset energy ratio.

Specifically, when the control device controls any one of the first attenuation device 23 and the second attenuation device 24 to rotate, the control device obtains the power of the reference light attenuated by the first attenuation device 23 and the power of the delay light attenuated by the second attenuation device 24 measured by the power meter in real time, and stops the rotation of the first attenuation device 23 and the second attenuation device 24 when the ratio of the power of the reference light attenuated by the first attenuation device 23 to the power of the delay light attenuated by the second attenuation device 24 is equal to the preset energy ratio. Optionally, when the preset energy ratio is 40%, the delay light with the preset delay in the double-pulse delay light beam effectively adjusts the surface morphology of the object polished by the reference light, and the effect of eliminating the ultrafast laser-induced surface periodic micro-nano structure on the surface of the object to be polished is best.

And step 13, combining the incident light beams by the second beam splitting device to obtain the double-pulse delay light beam.

Obtaining delayed light with preset delay after the delayed light passes through the step 11, and obtaining reference light with a preset energy ratio compared with the reference light through energy adjustment in the step 12; finally, the reference light attenuated by the first attenuation device 23 and the delayed light attenuated by the second attenuation device 24 are both incident to the second beam splitting device 22, and the second beam splitting device 22 combines the incident light beams to obtain the double-pulse delayed light beam with the preset delay and the preset energy ratio.

The double-pulse delayed light beam with the preset delay and the preset energy ratio output from the time domain shaping module 20 is incident to the light field regulation and control module 30. The light field regulation and control module 30 regulates the double-pulse delay light beam into a linearly distributed light field, and irradiates the light field to the surface of the object to be polished.

Since the linearly polarized gaussian laser beam cannot realize efficient scanning and polishing due to the limitation of the gaussian light field distribution, after the double-pulse delayed light beam with the preset delay and the preset energy ratio output from the time domain shaping module 20 is incident to the light field regulation and control module 30, the light field regulation and control module 30 regulates the double-pulse delayed light beam into a linearly distributed light field, and then irradiates the emergent light field to the surface of the object to be polished. So that single scanning can act on a larger area to be polished, thereby improving the utilization rate of the double-pulse delay light beam. .

In one embodiment, the light field adjusting module 30 includes a cylindrical plano-convex lens 31 and a focusing objective lens 32 sequentially disposed along the optical path. The cylindrical plano-convex lens 31 adjusts the double-pulse delay light beam into a light field distributed in a linear manner, and the light field is focused to the surface of the object to be polished through the focusing objective lens 32. Alternatively, the multiple of the focusing objective lens may be 20 times.

In one example implementation, the laser polishing system further includes an expanded beam collimation module 60. Before the double-pulse delayed light beams with preset delay and preset energy ratio output from the time domain shaping module 20 are reflected by the dichroic mirror and incident to the light field regulation and control module 30, the beam expanding and collimating module 60 performs beam expanding processing and beam collimating regulation on the double-pulse delayed light beams output from the time domain shaping module, and irradiates the regulated double-pulse delayed light beams to the light field regulation and control module.

In one implementation example, the beam expanding and collimating module 60 includes a first lens 61 and a second lens 62 sequentially disposed along the optical path.

The first lens 61 performs beam expansion processing on the double-pulse delayed light beam output by the time domain shaping module, and the light beam after beam expansion processing enters the second lens 62; the second lens 62 performs beam collimation adjustment on the beam after beam expansion processing, and transmits the adjusted double-pulse delay beam to the light field regulation and control module 30. Optionally, the first lens 61 is a concave lens; the second lens 62 is a convex lens.

In one embodiment, the laser polishing system further includes an article displacement table 70 for placing the object to be polished and a photographing device 80;

the control device controls the shooting device to shoot the surface of the object to be polished to obtain a surface image; and the control device controls the article displacement table to move according to the surface image so that the light field scans and polishes the surface of the object to be polished.

Specifically, since the surface area of the object to be polished is large, the double-pulse delay beam irradiated to the surface cannot polish the entire surface of the object at one time. In order to polish the surface of the object to be polished completely, the control device can control the object displacement table 70 on which the object to be polished is placed to move so as to drive the object to be polished to move, so that the double-pulse delay beam can polish the whole surface of the object. In order to more accurately control the movement of the article displacement table 70 and observe the polishing condition of the surface of the object to be polished, a shooting device 80 can be further arranged in the laser polishing system, and the control device controls the shooting device to shoot the surface of the object to be polished to obtain a real-time image of the surface to be polished; the control device controls the article displacement table to move according to the surface image so that the light field can accurately scan and polish the surface of the object to be polished.

In detail, as shown in fig. 1, sample light carrying surface information of an object to be polished is reflected by the surface of the object to be polished and enters a dichroic mirror 81, and the dichroic mirror 81 receives a double-pulse delayed light beam and the sample light, and then combines the two beams of light and reflects the two beams of light to a shooting device 80; the image pickup device 80 receives the light beam emitted from the dichroic mirror 81 to obtain a surface image. Optionally, the photographing device is a CCD. The linear distribution femtosecond laser after the time delay and pulse energy ratio is regulated and controlled is used for scanning, the large-area rough surface can be repaired by single scanning of the linear distribution light beam, and the polishing efficiency of the shaping femtosecond laser is improved by more than 10 times compared with the unshaped Gaussian femtosecond laser; finally obtaining a smooth surface with the roughness of about 100 nm.

In the laser polishing system provided by the embodiment of the invention, the laser polarization fixing module converts laser emitted by the laser light source into a laser beam with a fixed polarization direction; the laser polarization fixing module is used for converting laser emitted by the laser light source into linearly polarized light with a fixed polarization direction. The control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam to obtain a double-pulse delay beam with preset delay and preset energy ratio; the control device controls the time domain shaping module to perform beam splitting delay regulation and energy regulation on the laser beam, so that the surface quality of the laser beam after the laser beam acts on an object to be polished is improved; the obtained double-pulse delay light beam with the preset delay and the preset energy ratio can effectively eliminate the generation of an ultrafast laser-induced surface periodic micro-nano structure on the surface of the object to be polished, so that the surface roughness of the object to be polished is reduced after the surface of the object to be polished is polished by the double-pulse delay light beam, and the object polishing quality of laser is improved. The light field regulation and control module regulates the double-pulse delay light beam into a light field distributed in a linear mode and irradiates the light field to the surface of an object to be polished. The double-pulse delay light beam is adjusted to be a linear distributed light field through the light field regulation and control module, the utilization rate of the double-pulse delay light beam is improved, single scanning can act on a larger area to be polished, and the polishing efficiency of laser is improved.

Example two

Fig. 4 is a schematic structural diagram of a control device according to a second embodiment of the present invention. The control device includes: a processor 41, a memory 42 and a computer program 43 stored in said memory 42 and executable on said processor 41, such as a program for a method of speckle blurring of an image. The processor 41 executes the computer program 43 to implement the above-mentioned steps of controlling the time domain shaping module to perform beam splitting delay control and energy adjustment on the laser beam, such as steps S11 to S13 shown in fig. 2.

Illustratively, the computer program 43 may be partitioned into one or more modules that are stored in the memory 42 and executed by the processor 41 to accomplish the present application. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 43 in the control device. For example, the computer program 43 may be divided into a phase discrimination curve generation module, a sampling module, a linear parameter information generation module, a clustering module, and a positioning deviation calculation module, and each module has the following specific functions:

the delay adjusting module is used for controlling the displacement table to move by the control device according to the preset delay, and changing the optical path difference between the light to be adjusted and the reference light so as to enable the light to be adjusted to have the preset delay;

and the energy adjusting module is used for controlling the first attenuating device or the second attenuating device to rotate by the control device according to a preset energy ratio so as to enable the energy ratio between the reference light for energy attenuation and the light to be adjusted for energy attenuation through the second attenuating device to be the preset energy ratio.

The control means may include, but is not limited to, a processor 41, a memory 42, and a computer program 43 stored in the memory 42. It will be understood by those skilled in the art that fig. 4 is merely an example of a control device, and does not constitute a limitation of the device for blurring the band spot of an image, and may include more or less components than those shown, or combine some components, or different components, for example, the device for blurring the band spot of an image may further include an input-output device, a network access device, a bus, etc.

The Processor 41 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 42 may be an internal storage unit of the image blurring device with light spot, such as a hard disk or a memory of the image blurring device with light spot. The memory 42 may also be an external storage device, such as a plug-in hard disk provided on a device for blurring image spots, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like. Further, the memory 42 may also include both an internal storage unit with a spot blurring apparatus of an image and an external storage device. The memory 42 is used for storing the computer program and other programs and data required for the method of blurring an image with a spot. The memory 42 may also be used to temporarily store data that has been output or is to be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment. In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method embodiments may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims

1. A laser polishing system, comprising: the device comprises a laser polarization fixing module, a time domain shaping module, a light field regulating and controlling module and a control device;

2. The laser polishing system of claim 1, wherein the time-domain shaping module comprises a first beam splitting device, a second beam splitting device, a first attenuation device, a second attenuation device, and a displacement stage with a mirror group;

3. The laser polishing system of claim 2, wherein the control device controls the time domain shaping module to perform beam splitting delay control and energy adjustment on the laser beam to obtain a double-pulse delayed beam with a preset delay and a preset energy ratio, comprising:

4. The laser polishing system of claim 2, wherein the first beam splitting device and the second beam splitting device are both half-wave plates; the first attenuation device and the second attenuation device are both neutral density attenuation sheets;

5. The laser polishing system of claim 1, wherein the system further comprises an expanded beam collimation module;

6. The laser polishing system of claim 5, wherein the beam expanding and collimating module comprises a first lens and a second lens disposed in sequence along the optical path;

the first lens is a concave lens; the second lens is a convex lens.

7. The laser polishing system according to claim 1, further comprising an article displacement table for placing the object to be polished and a photographing device;

8. The laser polishing system of claim 1, wherein the laser polarization fixing module comprises a first wave plate and a polarization beam splitter disposed in sequence along the optical path;

9. The laser polishing system of claim 1, wherein the light field conditioning module comprises a cylindrical plano-convex lens and a focusing objective lens disposed in sequence along the light path;

10. A laser polishing method applied to the laser polishing system according to claim 3;