High-power adjustable laser spot output method and device

Abstract

The invention belongs to the technical field of laser, and particularly discloses a high-power adjustable laser spot output method and device. The method comprises the following steps: constructing a laser output array, and fixing the laser output array; arranging a lens assembly to collimate and focus a laser group output by the laser output array; and the focal length of the lens assembly is adjusted according to the shape of the preset special-shaped light spot, so that the collimation of each laser beam is independently controlled, and the output of the special-shaped light spots with different sizes and shape combinations is realized. The device comprises an output optical fiber array, an output optical fiber fixing tool, a light source output module and a lens assembly, the output optical fiber array is connected with the light source output module to output laser at the same time, and light spot collimation of the output light is achieved through the lens assembly. According to the invention, adjustable I-shaped, concentric-square-shaped, circular-ring-shaped and other special-shaped light spot output can be realized, the device has the advantages of small size, simple structure, flexible operation and the like, and the output special-shaped light spots can be changed according to task requirements.

Description

Technical Field

[0001] The present invention belongs to the field of laser technology, and more specifically, relates to a method and device for outputting a high-power adjustable laser spot. Background Art

[0002] With the continuous development and progress of the laser industry, the application scenarios of lasers are gradually increasing. Lasers are gradually applied to laser welding, laser cutting, laser marking and other aspects. This has extremely strict requirements on the laser spot. The shape of the laser spot and the ratio of the energy of each part of the spot need to be adjusted according to the needs of the actual scene.

[0003] Chinese patent CN202010194946.0 proposes a power-adjustable concentric point annular spot combiner, which can connect the pigtails of multiple laser modules to the annular spot combiner, so that the output light of different laser modules propagates in different areas of the optical fiber to finally realize the output of the annular spot. The ratio of the energy of each part in the annular spot is adjusted by adjusting the ratio of the output power of the laser modules.

[0004] Chinese patent CN202310877659.4 proposes a laser spot size adjustment device and method, which uses special lens conversion tooling and lenses to adjust the output spot size of a single-channel laser. By adjusting the lens conversion tooling, different lens groups are combined with the output port of the laser, and finally the spot size is adjusted. The more lenses there are, the wider the range of spot size adjustment.

[0005] However, the above outputs are all circular / annular light spots, and it is impossible to output special-shaped light spots such as "I"-shaped and "U"-shaped. However, with the continuous expansion of laser application scenarios, the required laser light spots are not only circular / annular light spots, but also more laser modules that can output other special-shaped light spots such as "I"-shaped and "U"-shaped. In addition, it is necessary to output multiple types of special-shaped light spots in the same system according to the requirements of different tasks. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the present invention provides a method and device for outputting a high-power adjustable laser spot, which can adjust the focal length of the lens assembly according to the shape of a preset special-shaped spot, so as to independently control the collimation of each laser beam and realize the output of special-shaped spots of different sizes and shapes.

[0007] To achieve the above object, according to one aspect of the present invention, a method for outputting a high-power adjustable laser spot includes the following method:

[0008] Step 1: construct a laser output array and fix the laser output array;

[0009] Step 2: Arrange a lens assembly to collimate and focus the laser group output by the laser output array;

[0010] Step 3: Adjust the focal length of the lens assembly according to the shape of the preset special-shaped light spot to independently control the collimation of each laser beam and achieve the output of special-shaped light spots of different sizes and shapes.

[0011] As a further preference, in step 2, each output optical fiber of the laser output array corresponds to a lens group, and the lens group is made of transparent shape memory polyimide.

[0012] As further preferred, in step 3, adjusting the focal length of the lens assembly comprises the following steps:

[0013] (31) obtaining thermodynamic and optical properties of the transparent shape memory polyimide;

[0014] (32) designing a lens group according to the curvature radius and aspheric coefficient of the lens, and performing shape memory effect training on the lens group prepared from transparent shape memory polyimide to ensure that the lens group can meet the required optical performance;

[0015] (33) The shape memory effect of the lens is triggered by changing its temperature, thereby adjusting the radius of curvature of the lens to control the collimation adjustment of each laser beam.

[0016] As further preferred, in step (32), the shape memory effect training of the lens group made of transparent shape memory polyimide comprises the following steps:

[0017] (321) a temperature control channel arranged along the circumference of each lens, wherein the temperature control channel is arranged along the outer diameter edge of the lens;

[0018] (322) changing the temperature of the lens by changing the temperature of the fluid in the temperature-controlled flow channel, so that the deformation of the edge of the lens is greater than the deformation of the center, thereby changing the curvature of the lens surface;

[0019] (323) repeating step (322) to perform shape memory effect training on the lens;

[0020] (324) The corresponding relationship between the curvature of the lens surface and the temperature after the shape memory effect training is completed is recorded.

[0021] As a further preference, in step (33), a PID control method is used to dynamically adjust the deformation temperature of each lens, thereby dynamically adjusting the curvature radius of the lens, so that each lens group can collimate the input laser.

[0022] As further preferred, the PID control method includes:

[0023]

[0024] Where u(t) is the control output, e(t) is the error, and Kp, Ki, and Kd are the proportional, integral, and derivative gains, respectively.

[0025] As a further preference, the shapes of the irregular light spot include an I-shape, a U-shape, a circular shape, and a ring shape.

[0026] According to another aspect of the present invention, there is also provided a device for outputting a high-power adjustable laser spot, comprising:

[0027] Output fiber array, used for independently outputting multiple lasers;

[0028] An optical fiber fixing tool, used for fixing the output optical fiber array;

[0029] A light source output module, connected to the output optical fiber array, for realizing simultaneous output of the output lasers;

[0030] The lens assembly is used to independently control the collimation and focusing of each laser beam to achieve spot output of different sizes and shapes.

[0031] As further preferred, it further includes a control module, wherein the control module is communicatively connected with the output optical fiber array, the light source output module and the lens assembly;

[0032] The lens assembly includes multiple lens groups and a temperature control unit for controlling the temperature of each lens group respectively. Each output optical fiber of the output optical fiber array corresponds to a lens group. The lens group is made of transparent shape memory polyimide. The temperature control unit is used to trigger the shape memory effect of the lens by changing the temperature of the lens according to the shape of the preset light spot, thereby adjusting the curvature radius of the lens to adjust its focus, thereby realizing the output of special-shaped light spots of different sizes and shapes.

[0033] As a further preferred embodiment, each lens group is provided with a temperature sensor to monitor temperature changes in real time;

[0034] The temperature control unit includes a temperature control channel arranged along the circumference of each lens. The temperature control channel is arranged along the outer diameter edge of the lens to achieve a gradient temperature change from the edge to the center of the lens, thereby changing the curved surface of the lens.

[0035] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0036] 1. The present invention realizes precise control of the size and shape of the laser spot by constructing a laser output array, arranging lens components and lens groups. The deformation temperature of each lens is dynamically adjusted through the PID control method, thereby dynamically adjusting the curvature radius of the lens, so that each lens group can collimate the input laser and realize the output of special-shaped spots of different sizes and shapes. This method not only improves the flexibility and adaptability of the laser system, but also ensures the stability of the system by precisely controlling the temperature conditions, thus having important practical value and broad application prospects in high-power laser applications.

[0037] 2. The present invention constructs a laser output array and arranges lens components, and the solution can achieve precise control of high-power laser spots. Each output fiber corresponds to a lens group made of transparent shape memory polyimide (TSMPI), so that the collimation of each laser beam can be independently controlled, thereby achieving the output of special-shaped spots of different sizes and shapes.

[0038] 3. The present invention adopts PID control method to dynamically adjust the deformation temperature of the lens, so that the lens group can automatically collimate the input laser. This automated control strategy improves the response speed and control accuracy of the system, while also optimizing the performance of the lens group and ensuring the consistency and reliability of the laser spot output. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a flow chart of a method for outputting a high-power adjustable laser spot according to an embodiment of the present invention;

[0040] Figure 2 It is a structural schematic diagram of a high-power adjustable laser spot output device involved in an embodiment of the present invention;

[0041] Figure 3 A schematic diagram showing a structure in which an output optical fiber array according to an embodiment of the present invention is arranged in a rectangular shape;

[0042] Figure 4 A schematic diagram showing a structure in which an output optical fiber array according to an embodiment of the present invention is arranged in a ring. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Example 1

[0045] like Figure 1 As shown, a method for outputting a high-power adjustable laser spot provided by an embodiment of the present invention includes the following steps:

[0046] Step 1: Construct a laser output array and fix the laser output array.

[0047] In this step, the output fiber array 1 is fixed by the output fiber fixing fixture 2, and after being fixed, it is connected to the light source output module 3 to realize simultaneous output of the laser. More specifically, in one embodiment, according to the shape of the irregular light spot, the corresponding optical fiber in the fiber array 1 is controlled to output laser. For example, if an irregular light spot in the shape of an "I" is output, each optical fiber constituting the corresponding shape is controlled to work, and the remaining optical fibers are not operated.

[0048] Step 2: Arrange the lens assembly to collimate and focus the laser group output by the laser output array.

[0049] In this step, in order to obtain a stable irregular light spot, it is necessary to collimate each laser beam output by the light source output module 3. Since the power and position of each laser beam are different, a group of lens groups is difficult to meet the collimation of each laser beam. Therefore, in the present invention, a lens group with adjustable focus is designed for each laser beam to adapt to the collimation of lasers of different powers.

[0050] More specifically, in one embodiment of the present invention, a lens array is designed, wherein each lens corresponds to an output optical fiber, so that the collimation and focusing of each laser beam can be independently controlled. The lens array is adjustable, allowing the user to adjust the focal length as needed to change the size and shape of the light spot.

[0051] More specifically, in one embodiment of the present invention, transparent shape memory polyimide is selected as the lens material. This material has excellent optical transparency and shape memory effect, and is suitable for optoelectronic devices, transparent flexible displays and other fields. In the design process of the lens group, the lens group is designed using optical design software (such as Zemax), taking into account the optical properties of transparent shape memory polyimide, such as refractive index and dispersion characteristics. The memory training method of each lens in the lens group is designed so that the lens triggers the shape change of the material by heating or cooling to achieve laser collimation of different powers.

[0052] More specifically, in one embodiment of the present invention, in the lens group, the focus adjustment of each lens can be calculated by the following formula:

[0053]

[0054] Where f is the focal length of the lens group, ni is the refractive index of the i-th lens, and Ri is the radius of curvature of the i-th lens.

[0055] In this embodiment, it is necessary to analyze the thermal characteristics of the lens assembly, including heat capacity, thermal conductivity and thermal expansion coefficient. The thermal distribution of the lens assembly is simulated using thermodynamic simulation software to predict the temperature distribution under different heating conditions.

[0056] Step three, adjust the focal length of the lens assembly according to the shape of the preset special-shaped light spot to independently control the collimation of each laser beam to achieve the output of special-shaped light spots of different sizes and shapes.

[0057] More specifically, in one embodiment of the present invention, adjusting the focal length of the lens assembly comprises the following steps:

[0058] (31) obtaining thermodynamic and optical properties of the transparent shape memory polyimide;

[0059] (32) designing a lens group according to the curvature radius and aspheric coefficient of the lens, and performing shape memory effect training on the lens group prepared from transparent shape memory polyimide to ensure that the lens group can meet the required optical performance;

[0060] (33) The shape memory effect of the lens is triggered by changing its temperature, thereby adjusting the radius of curvature of the lens to control the collimation adjustment of each laser beam.

[0061] More specifically, in one embodiment of the present invention, after the lens is prepared using transparent shape memory polyimide, the lens needs to be subjected to shape memory training.

[0062] More specifically, in one embodiment of the present invention, the shape memory effect training of a lens assembly made of transparent shape memory polyimide comprises the following steps:

[0063] (321) a temperature control channel arranged along the circumference of each lens, wherein the temperature control channel is arranged along the outer diameter edge of the lens;

[0064] (322) changing the temperature of the lens by changing the temperature of the fluid in the temperature-controlled flow channel, so that the deformation of the edge of the lens is greater than the deformation of the center, thereby changing the curvature of the lens surface;

[0065] (323) repeating step (322) to perform shape memory effect training on the lens;

[0066] (324) The corresponding relationship between the curvature of the lens surface and the temperature after the shape memory effect training is completed is recorded.

[0067] More specifically, in one embodiment of the present invention, the TSMPI lens is heated to above 190°C to deform it, and then the shape is fixed at room temperature. Heated to 190°C again, the lens will return to its initial shape. Repeat the above steps 100 times to complete the shape memory effect training. After multiple shape cycles, it is verified by transmittance testing in the visible light region of 450-800nm ​​to ensure that the transmittance exceeds 81%, thereby maintaining its stable optical transparency.

[0068] Of course, the above embodiment is only one embodiment of the present invention. In this embodiment, multiple gradient training temperatures are set to perform gradient temperature shape deformation training on the lens. After the training is completed, the corresponding relationship between the curvature of the lens surface and the temperature after the shape memory effect training is completed is recorded. In this way, the deformation temperature of each lens in the corresponding lens group can be adjusted directly according to the characteristics of the output laser, so as to achieve the collimation of the corresponding laser.

[0069] More specifically, in one embodiment of the present invention, in step (33), a PID control method is used to dynamically adjust the deformation temperature of each lens, thereby dynamically adjusting the curvature radius of the lens, so that each lens group can collimate the input laser.

[0070] The PID control method comprises:

[0071]

[0072] Where u(t) is the control output, e(t) is the error, and Kp, Ki, and Kd are the proportional, integral, and derivative gains, respectively.

[0073] Example 2

[0074] like Figure 2 As shown, this embodiment provides an output device for a high-power adjustable laser spot, comprising: an output fiber array 1, used to independently output multiple lasers; a fiber fixing tool 2, used to fix the output fiber array 1; a light source output module 3, connected to the output fiber array 1, used to achieve simultaneous output of the output lasers; a lens assembly 4, used to independently control the collimation and focusing of each laser beam to achieve the output of spots of different sizes and shapes.

[0075] Optionally, it further includes a control module, which is communicatively connected with the output optical fiber array 1, the light source output module 3 and the lens assembly 4;

[0076] The lens assembly 4 includes a plurality of lens groups and a temperature control unit for controlling the temperature of each lens group respectively. Each output optical fiber of the output optical fiber array 1 corresponds to a lens group. The lens group is made of transparent shape memory polyimide. The temperature control unit is used to trigger the shape memory effect of the lens by changing the temperature of the lens according to the shape of the preset light spot, thereby adjusting the curvature radius of the lens to adjust its focus, thereby realizing the output of special-shaped light spots of different sizes and shapes.

[0077] Optionally, a temperature sensor is provided on each lens group to monitor temperature changes in real time;

[0078] The temperature control unit includes a temperature control channel arranged along the circumference of each lens, and the temperature control channel is arranged along the outer diameter edge of the lens to achieve a gradient temperature change from the edge to the center of the lens, thereby changing the curved surface of the lens. In this embodiment, all heating fluids that can adjust the temperature range of lens deformation are applicable to the present invention, such as silicone oil, heat transfer oil, etc., which do not belong to the protection scope of the present invention.

[0079] Optionally, the control module is integrated with a PID controller, which records the corresponding relationship between the curvature of the lens surface and the temperature after the shape memory effect training is completed. In this way, the PID controller can be used to adjust the temperature of the fluid in the temperature control channel directly according to the characteristics of the output laser and the feedback value of the temperature sensor.

[0080] Generally, the PID control method includes:

[0081]

[0082] Where u(t) is the control output, e(t) is the error, and Kp, Ki, and Kd are the proportional, integral, and derivative gains, respectively.

[0083] Example 3

[0084] This embodiment provides a high-power adjustable laser spot output device, which includes: an output fiber array 1, an output fiber fixing tool 2, a light source output module 3, and a lens assembly 4. The output fiber array 1 is fixed by the output fiber fixing tool 2, and after being fixed, it is connected to the light source output module 3 to realize simultaneous output of the output laser, and the output light is collimated by the lens assembly 4, and finally an adjustable special-shaped light spot is output.

[0085] As a further preference, the output fiber array 1 refers to an array composed of multiple laser output fiber pigtails, the multiple lasers are independent of each other and the output power can be adjusted according to the requirements of the application scenario.

[0086] As a further preferred embodiment, the output optical fiber fixing tool 2 is used to fix the output optical fibers of multiple lasers to ensure that the output optical fibers are stable and reliable during the welding or laser output process without relative displacement.

[0087] As a further preference, the light source output module 3 refers to a high-power optical fiber end cap / connector. Different from conventional optical fiber end caps / connectors, the light source output module can simultaneously output multiple beams of high-power light source output end caps / connectors without causing crosstalk between them.

[0088] As a further preference, the lens assembly 4 is composed of one or more lenses, so as to match the light source output module 3 and finally output a collimated light spot.

[0089] Example 4

[0090] This embodiment is based on the embodiment 2, and its shaped light spot output mode is as follows:

[0091] Use the optical fiber fixing tool 2 to fix the output optical fiber of the laser according to the target required spacing and shape (square or round, etc.);

[0092] After the optical fiber is fixed, the output pigtail is connected to the light source output module in two ways. If the number of optical fibers is small, the output optical fiber is directly fused with the light source output module to achieve simultaneous output of multiple laser beams without interference; if the number of optical fibers is large, the output optical fiber is fixed in the optical fiber fixing fixture, and the optical fiber in the fixing fixture is melt-tapered using the fusion taper equipment to reduce the radius of the optical fiber and then cut the fixture to ensure that the output optical fiber is flat, and then the tapered optical fiber is fused with the light source output module;

[0093] After being connected to the light source output module, multiple beams of non-interfering lasers can be output. After the multiple beams of lasers are output, they are collimated through the lens assembly to achieve output.

[0094] like Figure 3 as well as Figure 4 As shown, when the above device is prepared, the shape of the output light spot can be adjusted by adjusting the output power of different lasers to achieve the output of special-shaped light spots. When all lasers output the same power laser at the same time, the shape of the output light spot is the shape of the optical fiber fixed in the fixed tooling; when an "I"-shaped output is required, the laser corresponding to the pigtail at the corresponding position in the fixed tooling should be selected to output the same power; when a "U"-shaped or circular light spot is required, the laser corresponding to the pigtail at the corresponding position should also be selected for laser output.

[0095] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for outputting a high-power adjustable laser spot, characterized in that: The following methods are included: Step 1: construct a laser output array and fix the laser output array; Step 2: Arrange a lens assembly to collimate and focus the laser group output by the laser output array; Step 3: Adjust the focal length of the lens assembly according to the shape of the preset special-shaped light spot to independently control the collimation of each laser beam and achieve the output of special-shaped light spots of different sizes and shapes.

2. The method for outputting a high-power adjustable laser spot according to claim 1, characterized in that: In step 2, each output optical fiber of the laser output array corresponds to a lens group, and the lens group is made of transparent shape memory polyimide.

3. The method for outputting a high-power adjustable laser spot according to claim 2, characterized in that: In step three, adjusting the focal length of the lens assembly comprises the following steps: (31) obtaining thermodynamic and optical properties of the transparent shape memory polyimide; (32) designing a lens group according to the curvature radius and aspheric coefficient of the lens, and performing shape memory effect training on the lens group prepared from transparent shape memory polyimide to ensure that the lens group can meet the required optical performance; (33) The shape memory effect of the lens is triggered by changing its temperature, thereby adjusting the radius of curvature of the lens to control the collimation adjustment of each laser beam.

4. The method for outputting a high-power adjustable laser spot according to claim 3, characterized in that: In step (32), the shape memory effect training of the lens assembly made of transparent shape memory polyimide comprises the following steps: (321) a temperature control channel arranged along the circumference of each lens, wherein the temperature control channel is arranged along the outer diameter edge of the lens; (322) changing the temperature of the lens by changing the temperature of the fluid in the temperature-controlled flow channel, so that the deformation of the edge of the lens is greater than the deformation of the center, thereby changing the curvature of the lens surface; (323) repeating step (322) to perform shape memory effect training on the lens; (324) The corresponding relationship between the curvature of the lens surface and the temperature after the shape memory effect training is completed is recorded.

5. The method for outputting a high-power adjustable laser spot according to claim 4, characterized in that: In step (33), a PID control method is used to dynamically adjust the deformation temperature of each lens, thereby dynamically adjusting the curvature radius of the lens, so that each lens group can collimate the input laser.

6. The method for outputting a high-power adjustable laser spot according to claim 2, characterized in that: The PID control method comprises: Where u(t) is the control output, e(t) is the error, and Kp, Ki, and Kd are the proportional, integral, and derivative gains, respectively.

7. A method for outputting a high-power adjustable laser spot according to any one of claims 1 to 6, characterized in that: The shapes of the irregular light spots include "I" shape, "U" shape, circular shape, and ring shape.

8. A high-power adjustable laser spot output device, characterized in that: include: An output fiber array (1) for independently outputting multiple lasers; An optical fiber fixing tool (2) used for fixing the output optical fiber array (1); A light source output module (3) connected to the output optical fiber array (1) and used to achieve simultaneous output of laser light; The lens assembly (4) is used to independently control the collimation and focusing of each laser beam to achieve light spot output of different sizes and shapes.

9. The device for outputting a high-power adjustable laser spot according to claim 8, characterized in that: It also includes a control module, which is communicatively connected with the output optical fiber array (1), the light source output module (3) and the lens assembly (4); The lens assembly (4) comprises a plurality of lens groups and a temperature control unit for controlling the temperature of each lens group respectively; each output optical fiber of the output optical fiber array (1) corresponds to a lens group; the lens group is made of transparent shape memory polyimide; the temperature control unit is used to trigger the shape memory effect of the lens by changing the temperature of the lens according to the shape of a preset light spot, thereby adjusting the radius of curvature of the lens to adjust its focus, thereby achieving the output of special-shaped light spots of different sizes and shapes.

10. The device for outputting a high-power adjustable laser spot according to claim 9, characterized in that: Each lens group is equipped with a temperature sensor to monitor temperature changes in real time; The temperature control unit includes a temperature control channel arranged along the circumference of each lens. The temperature control channel is arranged along the outer diameter edge of the lens to achieve a gradient temperature change from the edge to the center of the lens, thereby changing the curved surface of the lens.

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