Laser polarization state control device and method

Abstract

The present invention relates to a laser polarization state control device and method. A reflection unit is arranged on the output optical path of the laser. A 1 / 2 wave plate, a beam splitter prism, a 1 / 4 wave plate and a galvanometer are arranged in sequence on the reflection optical path of the reflection unit. The output end of the galvanometer faces the workpiece on the stage. A power meter for real-time monitoring and recording the output power of the beam splitter prism and the beam splitter optical path is arranged next to the stage. The polarization state of the laser is adjusted to circular polarization through the 1 / 4 wave plate. The angle of the 1 / 4 wave plate is adjusted so that the output laser beam is a stable circularly polarized light. The linear polarization state of the laser is dynamically adjusted. The laser beam first passes through the 1 / 2 wave plate and then passes through the beam splitter prism. The power change is recorded by rotating the 1 / 2 wave plate using a power meter to determine the optimal state of P light and S light of the linear polarized light. When cutting in the X direction, P light is used, and when cutting in the Y direction, it is switched to S light. Efficient generation and adjustment of circularly polarized and linearly polarized light is achieved.

Description

Technical Field

[0001] The invention relates to a laser polarization state control device and a method thereof, belonging to the technical field of laser processing equipment. Background Art

[0002] In the field of ultrafast laser micromachining, the polarization state of the laser has an important influence on the processing effect. The polarization state of the laser is mainly divided into linear polarization, circular polarization and elliptical polarization. Each polarization state interacts with the material in different ways, affecting the laser cutting, drilling and surface treatment effects. When cutting metals, especially high-reflectivity metals such as aluminum and copper, linearly polarized light can significantly improve the cutting efficiency due to its specific reflection characteristics. This phenomenon is due to the combination of the electric field vector direction of linearly polarized light and the characteristics of the metal surface, which optimizes the energy transmission and absorption process, reduces the heat-affected zone, and reduces the risk of material deformation and reduced cutting quality due to heat accumulation.

[0003] On the other hand, circularly polarized light shows superior uniformity and cutting stability when processing thin metal materials or workpieces with complex shapes. The energy distribution characteristics of circularly polarized light enable more uniform energy transfer during the cutting process, thereby effectively reducing edge effects and improving processing accuracy. This uniformity is especially important when processing tiny structures and delicate patterns, and can achieve high-quality surface treatment.

[0004] Although the influence of polarization state on laser processing has received widespread attention, the existing polarization state adjustment methods mainly rely on static polarizers and optical components. These traditional methods have many limitations in practical applications. First, traditional methods often lack sufficient flexibility and cannot quickly adapt to different processing requirements; second, the use of static optical components makes the adjustment accuracy insufficient and difficult to achieve real-time monitoring. In addition, the traditional polarization state adjustment process is complicated and difficult to operate, especially in high-power laser systems, these problems are more prominent.

[0005] At present, the research on polarization state adjustment is gradually developing towards intelligence and automation. With the continuous advancement of laser technology and optical components, the research and development of new polarization state control methods has become an important research direction. For example, by using a combination of various optical components such as wave plates, polarization beam splitters (PBS), and beam splitters, attempts are made to achieve dynamic polarization state adjustment of lasers. These new methods can not only improve the flexibility and accuracy of laser processing, but also provide better cutting results under different processing conditions.

[0006] However, the existing technology still has shortcomings. For example, although some studies have explored the effect of polarization state on cutting effect, there is a lack of systematic and operational polarization control methods. How to monitor and adjust the polarization state of the laser in real time during the actual processing process to cope with different materials and processing requirements is still a technical problem that needs to be solved urgently.

[0007] In summary, the polarization state of laser plays an important role in ultrafast laser micromachining, but the current polarization state adjustment method has certain limitations. Therefore, it is necessary to develop a new laser polarization state control method to effectively improve processing efficiency, improve processing quality, and promote the development of laser micromachining technology. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a laser polarization state control device and method.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] The laser polarization state control device is characterized in that it includes a 1 / 2 wave plate, a beam splitter prism and a 1 / 4 wave plate, a reflection unit is arranged on the output light path of the laser, and the reflection light path of the reflection unit is arranged in sequence with a 1 / 2 wave plate, a beam splitter prism, a 1 / 4 wave plate and a galvanometer, the output end of the galvanometer faces the workpiece on the stage, and a power meter for real-time monitoring and recording the output power of the beam splitter prism-beam splitter light path is arranged next to the stage.

[0011] Furthermore, in the above-mentioned laser polarization state control device, the reflection unit includes a first reflector and a second reflector arranged along the optical path.

[0012] Furthermore, in the above-mentioned laser polarization state control device, the carrier is an XY-θ axis motion platform.

[0013] Furthermore, in the above-mentioned laser polarization state control device, the laser is an ultraviolet picosecond laser.

[0014] Furthermore, in the above-mentioned laser polarization state control device, the laser is a 12W ultraviolet picosecond laser.

[0015] Furthermore, in the above-mentioned laser polarization state control device, an optical shutter is arranged at the output end of the laser.

[0016] The laser polarization state control method of the present invention comprises:

[0017] a) Generation and adjustment of circularly polarized light. The laser beam output by the laser first passes through a 1 / 2 wave plate, a beam splitter prism, and then a 1 / 4 wave plate. When the 1 / 4 wave plate rotates to a certain angle, the beam splitter prism divides the laser beam into two parts. The power of the laser beam passing through the beam splitter prism is monitored. After the laser beam passes through the beam splitter prism, the power meter records the output power of the laser in real time. The beam splitter prism is adjusted to rotate 360° to observe the power fluctuation of the laser beam passing through the beam splitter prism. When the power is stable and does not fluctuate, it can be determined that the position of the 1 / 4 wave plate is fixed. After removing the beam splitter prism, the laser beam passing through the 1 / 4 wave plate is considered to be circularly polarized light. By adjusting the rotation angle of the quarter wave plate, a stable circularly polarized light output is obtained.

[0018] b) Generation and adjustment of linear polarized light. The laser beam first passes through a 1 / 2 wave plate and then passes through a beam splitter. The laser beam is divided into P light and S light. The polarization state of the laser is mainly P light. By rotating the 1 / 2 wave plate and recording the power change of the laser beam after the beam splitter, the peak and valley moments of the power are identified, and the angle of the 1 / 2 wave plate is recorded. When the power reaches the peak, the corresponding 1 / 2 wave plate position is the P light state of the linear polarized light; when the power reaches the valley, the corresponding 1 / 2 wave plate position indicates the S light state of the linear polarized light. By adjusting the linear polarization state of the laser, the processing technology can be controlled.

[0019] Furthermore, in the above-mentioned laser polarization state control method, the polarization state of the laser is adjusted to circular polarization by a quarter wave plate, and the angle of the quarter wave plate is adjusted so that the output laser beam is a stable circularly polarized light, and the circularly polarized light provides a more uniform energy distribution;

[0020] On this basis, the linear polarization state of the laser is dynamically adjusted to optimize the cutting quality. The laser beam first passes through a 1 / 2 wave plate and then a beam splitter. The power change is recorded by a power meter by rotating the 1 / 2 wave plate to determine the optimal state of the P light and S light of the linear polarized light. When cutting in the X direction, P light is used, and when cutting in the Y direction, it is switched to S light.

[0021] Through dynamic adjustment, the cutting quality in the X and Y directions is optimized.

[0022] Furthermore, in the above-mentioned laser polarization state control method, the laser is output as stable circularly polarized light by rotating the 1 / 4 wave plate and using a beam splitter prism to measure the laser power fluctuation in real time; during the cutting process, the linear polarization state of the laser is dynamically adjusted by the 1 / 2 wave plate, and the power measurement is used to record the optimal state of P light and S light to optimize the cutting quality.

[0023] Compared with the prior art, the present invention has significant advantages and beneficial effects, which are specifically embodied in the following aspects:

[0024] The present invention realizes efficient generation and adjustment of circularly polarized and linearly polarized light. By scientifically configuring a variety of optical elements, combined with a quarter wave plate and a beam splitter, efficient and flexible control of the laser polarization state is achieved, giving full play to the advantages of different polarization states in applications such as metal cutting. By accurately adjusting the configuration of optical devices, the required circularly polarized and linearly polarized light can be provided in laser processing, improving processing effects and reducing material loss.

[0025] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by practicing the specific embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 : A schematic structural diagram of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, directional terms and order terms are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] like Figure 1As shown, the laser polarization state control device comprises a 1 / 2 wave plate 4, a beam splitter prism 5 and a 1 / 4 wave plate 6. The laser 1 is a 12W ultraviolet picosecond laser. An optical gate and a reflecting unit are sequentially arranged on the output optical path of the laser 1. The reflecting unit comprises a reflecting mirror 2 and a reflecting mirror 3 arranged along the optical path. A 1 / 2 wave plate 4, a beam splitter prism 5, a 1 / 4 wave plate 6 and a galvanometer 7 are sequentially arranged on the reflecting optical path of the reflecting unit. The output end of the galvanometer 7 faces a workpiece 8 on a stage 10. The stage 10 is an XY-θ axis motion platform. A power meter 9 for real-time monitoring and recording the output power of the beam splitter prism 5-beam splitter optical path is arranged next to the stage 10.

[0031] The laser polarization state control method specifically comprises:

[0032] a) Generation and adjustment of circularly polarized light. The laser beam output by the laser 1 first passes through the 1 / 2 wave plate 4, the beam splitter 5, and then passes through the 1 / 4 wave plate 6. When the 1 / 4 wave plate 6 rotates to a certain angle, the beam splitter 5 divides the laser beam into two parts. The power of the laser beam passing through the beam splitter prism is monitored. After the laser beam passes through the beam splitter prism 5, the power meter 9 records the output power of the laser in real time. The beam splitter prism 5 is adjusted to rotate 360° to observe the power fluctuation of the laser beam passing through the beam splitter prism 5. When the power is stable and does not fluctuate, it can be determined that the position of the 1 / 4 wave plate 6 is fixed. After removing the beam splitter prism 5, the laser beam passing through the 1 / 4 wave plate 6 is considered to be circularly polarized light. By adjusting the rotation angle of the quarter wave plate, a stable circularly polarized light output is obtained.

[0033] b) Generation and adjustment of linear polarized light. The laser beam first passes through the 1 / 2 wave plate 4 and then passes through the beam splitter prism 5. The laser beam is divided into P light and S light. The polarization state of the laser is mainly P light. By rotating the 1 / 2 wave plate 4 and recording the power change of the laser beam after the beam splitter prism 5, the peak and valley moments of the power are identified, and the angle of the 1 / 2 wave plate 4 is recorded. When the power reaches the peak, the corresponding position of the 1 / 2 wave plate 4 is the P light state of the linear polarized light; when the power reaches the valley, the corresponding position of the 1 / 2 wave plate 4 indicates the S light state of the linear polarized light. By adjusting the linear polarization state of the laser, the control of the processing technology is achieved.

[0034] The polarization state of the laser is adjusted to circular polarization through the 1 / 4 wave plate 6. The angle of the 1 / 4 wave plate 6 is adjusted to make the output laser beam a stable circularly polarized light. When circularly polarized light is used for cutting, the cutting quality in the X and Y directions is significantly improved, the quality of the cutting edge is close, and the burr and notch phenomenon is alleviated; circularly polarized light provides more uniform energy distribution during the cutting process of thin metal materials, improving the consistency and effect of processing;

[0035] Although circularly polarized light significantly improves the cutting quality, a small amount of burrs and notches are found in the X and Y directions. On this basis, the linear polarization state of the laser is dynamically adjusted to optimize the cutting quality. The laser beam first passes through the 1 / 2 wave plate 4 and then passes through the beam splitter prism 5. The power change is recorded by rotating the 1 / 2 wave plate 4 using the power meter 9 to determine the optimal state of the P light and S light of the linear polarized light. When cutting in the X direction, P light is used, and when cutting in the Y direction, it is switched to S light.

[0036] Through dynamic adjustment, the cutting quality in the X and Y directions is optimized. After adjustment, not only the burrs on the metal edge after cutting are significantly reduced, but also the cutting quality in the X and Y directions tends to be consistent, showing an excellent cutting effect. This shows the effectiveness of the practical application of the laser polarization state control method of the present invention.

[0037] By rotating the 1 / 4 wave plate 6 and using the beam splitter prism 5 to measure the laser power fluctuation in real time, the output laser is stable circularly polarized light; during the cutting process, the linear polarization state of the laser is dynamically adjusted by the 1 / 2 wave plate 4, and the optimal state of P light and S light is recorded by power measurement to optimize the cutting quality. The method of the present invention is particularly suitable for cutting thin metal materials, and verifies the significant influence of different polarization states on the cutting effect. When circularly polarized light is used for cutting, the consistency of cutting quality in the X and Y directions is improved, and the cutting effect is further improved by dynamic adjustment of linear polarization. The introduced real-time power monitoring system can dynamically respond to changes in cutting requirements to ensure stable output of laser energy.

[0038] In addition, the method of the present invention is not limited to thin metal materials, but can also be extended to the micro-processing field of other materials, showing a wide range of application potential and market value. Through the innovative configuration and dynamic adjustment strategy of optical elements, the present invention provides a new solution in the field of laser micro-processing technology.

[0039] In summary, the present invention realizes efficient generation and adjustment of circularly polarized and linearly polarized light, and realizes efficient and flexible control of laser polarization state by scientifically configuring multiple optical elements, combining 1 / 4 wave plates and beam splitters, and gives full play to the advantages of different polarization states in applications such as metal cutting. By accurately adjusting the configuration of optical devices, the required circularly polarized and linearly polarized light can be provided in laser processing, improving processing effects and reducing material loss.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0041] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A laser polarization state control device, characterized in that: The invention comprises a 1 / 2 wave plate (4), a beam splitter prism (5) and a 1 / 4 wave plate (6); a reflection unit is arranged on the output light path of the laser (1); a 1 / 2 wave plate (4), a beam splitter prism (5), a 1 / 4 wave plate (6) and a galvanometer (7) are arranged in sequence on the reflection light path of the reflection unit; the output end of the galvanometer (7) faces a processing part (8) on a carrier (10); and a power meter (9) for real-time monitoring and recording the output power of the beam splitter prism (5) on the beam splitter light path is arranged next to the carrier (10).

2. The laser polarization state control device according to claim 1, characterized in that: The reflection unit comprises a reflector 1 (2) and a reflector 2 (3) arranged along the light path.

3. The laser polarization state control device according to claim 1, characterized in that: The carrier (10) is an XY-θ axis motion platform.

4. The laser polarization state control device according to claim 1, characterized in that: The laser (1) is an ultraviolet picosecond laser.

5. The laser polarization state control device according to claim 4, characterized in that: The laser (1) is a 12W ultraviolet picosecond laser.

6. The laser polarization state control device according to claim 1, characterized in that: An optical shutter is arranged at the output end of the laser (1).

7. A method for controlling laser polarization state using the device of claim 1, characterized in that: Include: a) Generation and adjustment of circularly polarized light. The laser beam output by the laser (1) first passes through a 1 / 2 wave plate (4), a beam splitter (5), and then passes through a 1 / 4 wave plate (6). When the 1 / 4 wave plate (6) rotates to a certain angle, the beam splitter (5) splits the laser beam into two parts. The power of the laser beam passing through the beam splitter is monitored. After the laser beam passes through the beam splitter (5), the power meter (9) records the output power of the laser in real time. The beam splitter (5) is adjusted to rotate 360° to observe the power fluctuation of the laser beam passing through the beam splitter (5). When the power is stable and does not fluctuate, it can be determined that the position of the 1 / 4 wave plate (6) is fixed. After the beam splitter (5) is removed, the laser beam passing through the 1 / 4 wave plate (6) is considered to be circularly polarized light. By adjusting the rotation angle of the quarter wave plate, a stable circularly polarized light output is obtained. b) Generation and adjustment of linear polarized light. The laser beam first passes through a 1 / 2 wave plate (4) and then passes through a beam splitter (5). The laser beam is divided into P light and S light. The polarization state of the laser is mainly P light. By rotating the 1 / 2 wave plate (4) and recording the power change of the laser beam after the beam splitter (5), the peak and valley moments of the power are identified and the angle of the 1 / 2 wave plate (4) is recorded. When the power reaches the peak, the corresponding position of the 1 / 2 wave plate (4) is the P light state of the linear polarized light; when the power reaches the valley, the corresponding position of the 1 / 2 wave plate (4) indicates the S light state of the linear polarized light. The processing technology is controlled by adjusting the linear polarization state of the laser.

8. The laser polarization state control method according to claim 7, characterized in that: The polarization state of the laser is adjusted to circular polarization by a quarter wave plate (6), and the angle of the quarter wave plate (6) is adjusted so that the output laser beam is a stable circularly polarized light, and the circularly polarized light provides a more uniform energy distribution; On this basis, the linear polarization state of the laser is dynamically adjusted. The laser beam first passes through a 1 / 2 wave plate (4) and then passes through a beam splitter (5). The power change is recorded by a power meter (9) by rotating the 1 / 2 wave plate (4) to determine the optimal state of the P light and the S light of the linear polarized light. When cutting in the X direction, the P light is used, and when cutting in the Y direction, it is switched to the S light. Through dynamic adjustment, the cutting quality in the X and Y directions is optimized.

9. The laser polarization state control method according to claim 7, characterized in that: By rotating a quarter wave plate (6) and using a beam splitter (5) to measure laser power fluctuations in real time, the output laser is stable circularly polarized light; during the cutting process, the linear polarization state of the laser is dynamically adjusted through a half wave plate (4), and the optimal state of P light and S light is recorded by power measurement.

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