Method and device for outputting high-power adjustable laser spot

Abstract

This invention belongs to the field of laser technology and specifically discloses a method and device for outputting high-power adjustable laser beams. The method includes: constructing and fixing a laser output array; arranging a lens assembly to collimate and focus the laser beams output from the array; and adjusting the focal length of the lens assembly according to the shape of a preset irregular laser beam to independently control the collimation of each laser beam, thereby achieving output of irregular laser beams with different sizes and shapes. The device includes: an output fiber array, an output fiber fixing fixture, a light source output module, and a lens assembly. The output fiber array is connected to the light source output module to achieve simultaneous laser output, and the output light is collimated by the lens assembly. This invention can achieve adjustable "I"-shaped, "U"-shaped, and circular irregular laser beam outputs, and has advantages such as small size, simple structure, and flexible operation. Furthermore, the output irregular laser beams can be changed according to task requirements.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and more specifically, relates to a method and apparatus for outputting a high-power adjustable laser spot. Background Technology

[0002] With the continuous development and progress of the laser industry, the application scenarios of lasers are gradually increasing. Lasers are being applied to laser welding, laser cutting, and laser marking, which places extremely stringent requirements on the laser spot. The shape of the laser spot and the ratio of energy in each part of the spot need to be adjusted according to the needs of the actual scenario.

[0003] Chinese patent CN202010194946.0 proposes a power-adjustable concentric annular spot combiner, which connects the pigtails of multiple laser modules to the annular combiner, allowing the output light of different laser modules to propagate in different regions of the optical fiber and ultimately achieve the output of an annular spot. The ratio of energy in each part of the annular spot can be 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 a special lens conversion fixture and lens to adjust the output spot size of a single laser. By adjusting the lens conversion fixture, 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 outputs mentioned above are all circular / ring-shaped light spots, and cannot output irregularly shaped light spots such as "I" or "U". As the application scenarios of lasers continue to expand, the required laser light spots are not only circular / ring-shaped, but also more laser modules that can output other irregularly shaped light spots such as "I" or "U". Furthermore, it is necessary to output multiple types of irregularly shaped light spots within the same system according to the needs of different tasks. Summary of the Invention

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

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

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

[0009] Step two: arranging the lens assembly to collimate and focus the laser groups outputted by the laser output array;

[0010] Step three: adjusting 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, realizing the output of special-shaped light spots with different sizes and shape combinations.

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

[0012] As a further preferred, in step three, the adjustment of the focal length of the lens assembly includes the following steps:

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

[0014] (32) Design the lens group according to the curvature radius and aspherical coefficient of the lens, and train the lens group made of transparent shape memory polyimide for shape memory effect to ensure that the lens group can meet the required optical performance;

[0015] (33) Trigger the shape memory effect of the lens by changing its temperature to adjust the curvature radius of the lens to control the collimation adjustment of each laser beam.

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

[0017] (321) Arrange temperature control channels circumferentially along each lens, and arrange the temperature control channels along the outer diameter edge of the lens;

[0018] (322) Change the temperature of the fluid in the temperature control channel to change the temperature of the lens, so that the deformation of the edge of the lens is greater than that of the center, thereby changing the curvature of the lens;

[0019] (323) Repeat step (322) to train the lens for shape memory effect;

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

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

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

[0023]

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

[0025] As a further preference, the shape of the abnormal light spot includes "I"-shaped, "mouth"-shaped, circular ring-shaped, and annular-shaped.

[0026] According to another aspect of the present invention, there is also provided an output device for a high-power adjustable laser light spot, including: <{

[0027] An output fiber optic array for independently outputting multiple lasers;

[0028] A fiber optic fixing tooling for fixing the output fiber optic array;

[0029] A light source output module connected to the output fiber optic array for realizing simultaneous output of the output laser;

[0030] A lens assembly for independently controlling the collimation and focusing of each laser beam to realize the output of light spots of different sizes and shapes.

[0031] As a further preference, it further includes a control module, and the control module is communicatively connected to the output fiber optic array, the light source output module, and the lens assembly;

[0032] The lens assembly includes a plurality of lens groups and a temperature control unit for respectively controlling the temperature of each lens group. Each output fiber of the output fiber optic array corresponds to a lens group. The lens group is prepared from transparent shape memory polyimide. The temperature control unit is used to trigger its shape memory effect by changing the temperature of the lens according to the shape of the preset light spot, so as to adjust the curvature radius of the lens and thus adjust its focal point, so as to realize the output of abnormal light spots with different combinations of sizes and shapes.

[0033] As a further preference, a temperature sensor is provided on each lens group to monitor the temperature change in real time;

[0034] The temperature control unit includes a temperature control flow channel arranged circumferentially along each lens. The temperature control flow channel is arranged along the outer diameter edge of the lens to realize the gradient temperature change of the lens from the edge to the center, so as to change the surface change of the lens.

[0035] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following technical advantages are mainly possessed:

[0036] 1.The present application realizes precise control of laser spot size and shape by constructing a laser output array, arranging a lens assembly, and arranging a lens group. The deformation temperature of each lens is dynamically adjusted by a PID control method, thereby dynamically adjusting the radius of curvature of the lens, so that each lens group can collimate the input laser to realize different size and shape combination of special-shaped spot output. 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, thereby having important practical value and broad application prospect in high-power laser applications

[0037] 2.The present application realizes precise control of high-power laser spot by constructing a laser output array and arranging a lens assembly. 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 to realize different size and shape combination of special-shaped spot output.

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

[0039] Figure 1 is a flowchart of a high-power adjustable laser spot output method related to an embodiment of the present application;

[0040] Figure 2 is a structural schematic diagram of a high-power adjustable laser spot output device related to an embodiment of the present application;

[0041] Figure 3 represents a structural schematic diagram of an output fiber array arranged in a rectangular shape related to an embodiment of the present application;

[0042] Figure 4 represents a structural schematic diagram of an output fiber array arranged in a ring shape related to an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0044] Embodiment 1

[0045] AsFigure 1 As shown in the figure, an embodiment of the present invention provides a method for outputting a high-power adjustable laser spot, comprising the following steps:

[0046] Step 1: Construct the 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 fixing, it is connected to the light source output module 3 to achieve simultaneous laser output. More specifically, in one embodiment, the laser output of the corresponding fiber in the fiber array 1 is controlled according to the shape of the irregular light spot. For example, if an "I"-shaped irregular light spot is output, the individual fibers constituting the corresponding shape are controlled to work, while the remaining fibers are not working.

[0048] Step 2: Arrange the lens assembly to collimate and focus 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 single lens group is difficult to meet the collimation of each laser beam. Therefore, in this invention, a lens group with adjustable focus is designed for each laser beam to adapt to the collimation of lasers with different power.

[0050] More specifically, in one embodiment of the invention, a lens array is designed, wherein each lens corresponds to an output fiber, thus allowing independent control of the collimation and focusing of each laser beam. 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 possesses excellent optical transparency and shape-memory effect, making it suitable for fields such as optoelectronic devices and transparent flexible displays. During the design of the lens group, optical design software (such as Zemax) is used to design the lens group, taking into account the optical properties of the transparent shape-memory polyimide, such as refractive index and dispersion characteristics. A memory training method is designed for each lens in the lens group, allowing the lens to trigger shape changes in the material through heating or cooling to achieve laser collimation at different power levels.

[0052] More specifically, in one embodiment of the present invention, the focus adjustment of each lens in the lens group can be calculated using 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, the thermal properties of the lens group need to be analyzed, including heat capacity, thermal conductivity and thermal expansion coefficient. The thermal distribution of the lens group is simulated by 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, and realize the output of special-shaped light spots with different sizes and shapes.

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

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

[0059] (32) Design the lens group according to the curvature radius and asphericity coefficient of the lens, and train the shape memory effect of the lens group made of transparent shape memory polyimide, to ensure that the lens group can meet the required optical performance;

[0060] (33) Trigger the shape memory effect of the lens by changing its temperature, to adjust the curvature radius of the lens, and control the collimation adjustment of each laser beam.

[0061] More specifically, in one embodiment of the present application, after the transparent shape memory polyimide is used to prepare the lens, the lens needs to be trained for shape memory.

[0062] More specifically, in one embodiment of the present application, the step of training the shape memory effect of the lens group made of transparent shape memory polyimide includes the following steps:

[0063] (321) Arrange temperature control channels along the circumference of each lens, and arrange the temperature control channels along the outer diameter edge of the lens;

[0064] (322) Change the temperature of the fluid in the temperature control channel to change the temperature of the lens, so that the deformation of the edge of the lens is greater than that of the center, thereby changing the curvature of the lens;

[0065] (323) Repeat step (322) to train the shape memory effect of the lens;

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

[0067] More specifically, in one embodiment of the present application, the TSMPI lens is heated to above 190°C to deform it, and then the shape is fixed at room temperature. Reheating to 190°C, the lens will return to the original shape. Repeat the above steps 100 times to complete the shape memory effect training. After multiple shape cycles, it is verified by transmission in the 450-800nm visible light region to ensure that the transmission is more than 81% to maintain its stable optical transparency.

[0068] Of course, the above embodiment is only one embodiment of the present application, in which multiple gradient training temperatures are set to train the lens for gradient temperature shape deformation training. After training, the corresponding relationship between the curvature of the lens surface after shape memory effect training is completed and the temperature 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 realize the collimation of the corresponding laser.

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

[0070] The PID control method includes:

[0071]

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

[0073] Embodiment 2

[0074] As Figure 2 shown, the present embodiment provides an output device of high-power adjustable laser spot, which comprises: an output fiber array 1 for independently outputting multiple lasers; a fiber fixing tool 2 for fixing the output fiber array 1; a light source output module 3 connected with the output fiber array 1, for realizing simultaneous output of output laser; a lens assembly 4 for independently controlling the collimation and focusing of each laser beam to realize the output of different size and shape of light spot.

[0075] Optionally, it also includes a control module, which is in communication connection with the output fiber array 1, the light source output module 3 and the lens assembly 4;

[0076] 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 fiber of the output fiber array 1 corresponds to a lens group, the lens group is made of transparent shape memory polyimide, and 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, so as to adjust the radius of curvature of the lens, adjust the focal point, and realize the output of light spots with different sizes and shapes.

[0077] Optionally, a temperature sensor is arranged on each lens group to monitor the temperature change in real time.

[0078] The temperature control unit comprises a temperature control flow channel arranged circumferentially around each lens, and the temperature control flow channel is arranged along the outer diameter edge of the lens to realize the gradient temperature change of the lens from the edge to the center, so as to change the curvature of the lens. In this embodiment, all heating fluids that can realize the temperature range adjustment of the lens deformation are suitable for the present application, such as silicone oil and heat-conducting oil, which are not within the protection scope of the present application.

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

[0080] Generally, the PID control method comprises:

[0081]

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

[0083] Embodiment 3

[0084] The embodiment provides an output device of a high-power adjustable laser light spot, which comprises four parts of 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 is connected with the light source output module 3 to realize the simultaneous output of the output laser. The output light is collimated by the lens assembly 4 to realize the adjustable special-shaped light spot output.

[0085] As a further preferred, the output fiber array 1 refers to an array composed of a plurality of laser output tail fibers, and the plurality of lasers are independent of each other and the output power can be adjusted according to the application scene requirements.

[0086] As a further preferred embodiment, the output fiber fixing fixture 2 is used to fix the output pigtails of multiple lasers, ensuring that the output fiber is stable and reliable during fusion splicing or laser output, and that no relative displacement occurs.

[0087] As a further preferred embodiment, the light source output module 3 refers to a high-power fiber optic end cap / connector. Unlike conventional fiber optic end caps / connectors, this light source output module can simultaneously output multiple high-power light source output end caps / connectors without crosstalk between them.

[0088] As a further preferred embodiment, the lens assembly 4 is composed of one or more lenses to ensure matching with the light source output module 3, ultimately outputting a collimated light spot.

[0089] Example 4

[0090] Based on Example 2, this embodiment outputs irregularly shaped light spots in the following manner:

[0091] The output optical fibers of the laser are fixed according to the target requirements in terms of spacing and shape (square or round, etc.) using the optical fiber fixing fixture 2.

[0092] After the optical fiber is fixed, the output pigtail is connected to the light source output module using two methods. If the number of optical fibers is small, the output optical fiber is directly fused to 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 fused and tapered using a fusion tapering device to reduce the radius of the optical fiber. After cutting the fixture to ensure that the output optical fiber is flat, the tapered optical fiber is then fused to the light source output module.

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

[0094] like Figure 3 as well as Figure 4 As shown, once the above device is fabricated, the shape of the output spot can be adjusted by regulating the output power of different lasers, thus achieving irregularly shaped spot output. When all lasers output the same power simultaneously, the shape of the output spot is the shape fixed by the optical fiber within the fixture. For an "I"-shaped output, the laser corresponding to the pigtail at the corresponding position within the fixture should be selected to output the same power. Similarly, for a "U"-shaped or circular spot output, the laser corresponding to the pigtail at the corresponding position should be selected for laser output.

[0095] Those skilled in the art will readily understand that the above description is merely 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 within the scope of protection of the present invention.

Claims

1. A method of outputting a high-power adjustable laser spot, characterized by, It includes the following methods: 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 beam 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 with different sizes and shape combinations; In Step 2, each output optical fiber of the laser output array corresponds to a lens group, and the lens group is prepared from transparent shape memory polyimide; In Step 3, the adjustment of the focal length of the lens assembly includes the following steps: (31) Obtain the thermodynamic and optical properties of the transparent shape memory polyimide; (32) Design the lens group according to the curvature radius and aspheric coefficient of the lens, and conduct 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) Trigger its shape memory effect by changing the temperature of the lens, so as to adjust the curvature radius of the lens and control the collimation adjustment of each laser beam; In Step (32), the shape memory effect training of the lens group prepared from transparent shape memory polyimide includes the following steps: (321) Thermostatic control channels arranged circumferentially along each lens, and the thermostatic control channels are arranged along the outer diameter edge of the lens; (322) Change the temperature of the lens by changing the temperature of the fluid in the thermostatic control channel, so that the deformation of the edge of the lens is greater than the deformation of the center, thereby changing the surface curvature of the lens; (323) Repeat Step (322) to conduct shape memory effect training on the lens; (324) Record the corresponding relationship between the surface curvature and temperature of the lens after the shape memory effect training is completed.

2. The method of claim 1, wherein, In Step (33), the PID control method is used to dynamically adjust the deformation temperature of each lens, so as to dynamically adjust the curvature radius of the lens, so that each lens group collimates the input laser.

3. The method of claim 1 or 2, wherein, The shapes of the special-shaped light spots include "I" shape, "square frame" shape, and ring shape.

4. An apparatus for outputting a high-power adjustable laser spot for implementing the method for outputting a high-power adjustable laser spot according to any one of claims 1 to 3, characterized in that, It includes: An output optical fiber array (1) for independently outputting multiple lasers; An optical fiber fixing tooling (2) for fixing the output optical fiber array (1); A light source output module (3) connected to the output optical fiber array (1) for realizing the simultaneous output of the output laser; A lens assembly (4) for independently controlling the collimation and focusing of each laser beam and realizing the output of light spots with different sizes and shapes.

5. A high power adjustable laser spot output device according to claim 4, wherein, It further includes a control module, and the control module is communicatively connected to the output optical fiber array (1), the light source output module (3), and the lens assembly (4); The lens assembly (4) includes multiple lens groups and a temperature control unit for respectively controlling the temperature of each lens group. Each output optical fiber of the output optical fiber array (1) corresponds to a lens group. The lens group is prepared from transparent shape memory polyimide. The temperature control unit is used to trigger its shape memory effect by changing the temperature of the lens according to the shape of the preset light spot, so as to adjust the curvature radius of the lens and adjust its focal point, thereby realizing the output of special-shaped light spots with different sizes and shape combinations.

6. A high power adjustable laser spot output device according to claim 5, wherein, A temperature sensor is provided on each lens group to monitor the temperature change in real time; The temperature control unit includes temperature control flow channels arranged circumferentially along each lens, which are arranged along the outer diameter edge of the lens to achieve a gradient temperature change of the lens from the edge to the center, thereby changing the curvature change of the lens.

Images