A control device and control method for rapid power rise of a fiber laser

Abstract

The application provides a kind of control device and control method of rapid rise of fiber laser power, including: laser main body, including pump source assembly and laser output unit;Pump source assembly includes main pump source group and auxiliary pump source group;Power monitoring module is used to collect the output power of laser in real time, converts the power signal collected into electrical signal, and is transmitted to control module;Control module is used to receive the power signal transmitted by power monitoring module, identifies the interval where current power is located, and generates driving control signal;Control module includes microprocessor and algorithm logic unit;Drive module includes current driver and temperature controller;Current driver includes constant current driving circuit board and grouping driving unit;Power module.The application can promote the rapid and stable rise of laser output power to set power, and has high safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a control device and control method for rapidly increasing the power of a fiber laser. Background Technology

[0002] With the rapid development of laser technology, high-power fiber lasers have been widely used in industrial processing, military and other fields due to their advantages such as good beam quality, small size, high conversion efficiency and good heat dissipation. Pump source lasers have become one of the mainstream application models due to their high pump efficiency and low energy consumption.

[0003] Currently, 1000W fiber lasers composed of 976nm pump sources exhibit significant segmented differences during power rise: the rise time for the 0-90% power segment is only 1ms, demonstrating rapid response; however, the rise time for the 90%-100% set power segment (i.e., rising from 900W to 1000W) is as long as 2 minutes, severely impacting the laser's working efficiency and application experience. This fails to meet the demands of rapid start-up and shutdown and rapid power switching in industrial processing scenarios, such as continuous operations like laser cutting and welding. Excessive power rise time can lead to decreased processing accuracy, reduced processing efficiency, and even material waste.

[0004] In addition, existing lasers, in order to increase laser output power during the design process, make it difficult to balance rapid power rise and output stability, which can easily lead to power overshoot or fluctuations, damaging laser components or affecting processing quality. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a control device and method for rapidly increasing the power of a fiber laser, which can enable the output power of the laser to rise rapidly and stably to a set power, solving the problems of gain saturation and unreasonable accumulation of inverted particles in the high power range, resulting in stable laser output and high safety and reliability.

[0006] The embodiments of the present invention are achieved through the following technical solutions: A control device for rapidly increasing the power of a fiber laser, comprising: The laser body includes a pump source assembly and a laser output unit; the pump source assembly includes a main pump source group and an auxiliary pump source group, and the laser output unit includes a gain fiber, a transmission fiber, a resonant cavity for amplifying laser oscillation, and a cladding stripper for stripping cladding light. A power monitoring module is used to collect the output power of the laser in real time, convert the collected power signal into an electrical signal, and transmit it to the control module; the power monitoring module includes an optical power sensor and a data acquisition circuit. The control module is used to receive the power signal transmitted by the power monitoring module, identify the current power range, and generate a drive control signal; the control module includes a microprocessor and an algorithm logic unit. The drive module includes a current driver and a temperature controller; the current driver includes a constant current drive circuit board and a group drive unit; the constant current drive circuit board is used to realize linear soft start and constant current output; the group drive unit is used to switch drive modes and adjust the drive current of the pump source. The power supply module is used to provide a stable operating power supply for the power monitoring module, the control module, the drive module and the laser body.

[0007] According to a preferred embodiment, the pump source assembly further includes an isolation unit for isolating the reverse ASE light and an AWL active wavelength locking unit for outputting stable pump light.

[0008] According to a preferred embodiment, the resonant cavity includes a high-reflectivity grating, a ytterbium-doped gain fiber, and a low-reflectivity grating.

[0009] According to a preferred embodiment, the constant current drive circuit includes a power control element MOSFET and an operational amplifier follower to control the reference voltage; The driving modes include conventional constant current driving mode, pre-compensation driving mode, and constant power driving mode.

[0010] According to a preferred embodiment, the power module includes a DC power supply unit and a filter circuit unit.

[0011] According to a preferred embodiment, the power monitoring module is a high-speed power monitor, the monitoring port of the high-speed power monitor is provided with a filter, and the power measurement range of the power monitoring module is 0-1200W.

[0012] According to a preferred embodiment, the pump source assembly includes at least three main pump source groups and at least two auxiliary pump source groups; Both the main pump source group and the auxiliary pump source group are composed of 976nm pump sources.

[0013] According to a preferred embodiment, the microprocessor uses an ARM Cortex-M4 series chip with a main frequency of not less than 240MHz, which can quickly process power monitoring signals and generate drive control signals. The constant current drive circuit board adopts a parallel output of 4 sets of constant current circuits, which can accurately adjust the pump source drive current. The current adjustment accuracy of the constant current drive circuit board is not less than 0.1A, and the drive voltage range of the constant current drive circuit board is 0-48V.

[0014] A method for controlling the rapid increase of power in a fiber laser, specifically including the following steps: Step S100: The output power of the laser is collected in real time through the power monitoring module to determine the current power range and complete the identification of power segments; The range includes a low power range and a high power range. The power is set to 1000W. The low power range corresponds to 0-900W, and the high power range corresponds to 900-1000W. Step S200: When it is detected that the current output power of the laser is in the low power range, the driving module adopts the conventional constant current driving mode, controls the pump source component to output pump light, and drives the output power of the laser to rise from 0W to 900W (0% to 90%) in a rise time of 1ms. Through the AWL active wavelength locking unit, the pump light wavelength is kept stable in the range of 976±3nm. Step S300: When the laser's current output power is detected to have reached the set power of 900W, switch to the pre-compensation drive mode. The drive module groups multiple 976nm pump sources into a main pump source group and an auxiliary pump source group according to the preset power compensation parameters. At the same time, the AWL active wavelength locking unit is activated. The main pump source group maintains the current drive current unchanged, while the auxiliary pump source group instantly increases the drive current to a preset threshold. The preset threshold is set according to the set power requirement to ensure that the pump light power output by the auxiliary pump source group can quickly compensate for the gain loss in the high power range. In step S400, while the pre-compensation drive mode is started, the power monitoring module collects the laser output power in real time at a sampling frequency of 100MHz, compares the collected actual power with the preset power boost curve, and calculates the power deviation. Based on the power deviation, the drive module adjusts the drive current of the main pump source group and the auxiliary pump source group in real time through the PID negative feedback control algorithm, driving the laser power to rise rapidly from the set power of 900W to the set power of 1000W, with the rise time controlled within 2ms. In step S500, when the output power of the laser reaches the set power of 1000W, the drive module switches to constant power drive mode. Combined with the real-time feedback of the power monitoring module, the pump source drive current is adjusted to maintain the laser output power stability, with the fluctuation range controlled within ±1%. At the same time, the pump light wavelength is continuously locked through the AWL active wavelength locking unit to complete the control of the laser power increase.

[0015] According to a preferred embodiment, in step S100, the high-speed power monitor collects the output power of the laser in real time at a sampling frequency of 100MHz. The filter set at the monitoring port of the high-speed power monitor has a transmittance of ≥95% for signal light and a transmittance of ≤5% for pump light. The signal light is incident on the high-speed power monitor and is within the power monitoring range of the high-speed power monitor.

[0016] According to a preferred embodiment, in step S300, the main pump source group maintains the current driving current unchanged, and the current driving current is 10A. The preset threshold of the drive current is determined by the following method: the gain loss characteristics of the 1000W fiber laser in the 900-1000W (90% to 100%) power range are tested in advance, and the output power-drive current curve of the 976nm pump source is combined to determine that the preset threshold of the drive current of the auxiliary pump source group is 12A.

[0017] According to a preferred embodiment, in step S400, the power deviation is calculated using the following formula: ΔP(t)=Pref(t)-Pfb(t) Where ΔP(t) is the power deviation at time t; Pref(t) is the target power at time t; and Pfb(t) is the actual output power at time t.

[0018] According to a preferred embodiment, the PID negative feedback control algorithm adopts positional PID control, and its output is the adjustment amount of the pump source drive current, calculated as: u(t) = 0.8*ΔP(t) + 0.03*∫ t o ΔP(t)dt+0.2*dΔP(t) / dt Where u(t) is the adjustment amount of the pump source drive current at time t; ∫t0ΔP(t)dt is the power deviation integral from when the laser's output power enters the 90% range (t=0) to the current time t, i.e., the cumulative past deviation.

[0019] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: This invention includes a power monitoring module, a control module, and a drive module. It collects the output power of the laser in real time and uses the drive module to switch modes and adjust the current based on the data. This enables the laser output power to rise quickly and stably to the set power, solving the problems of gain saturation and unreasonable accumulation of inverted particles in the high power range. The laser output is stable, and the safety and reliability are high. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1A schematic diagram of the structure of a control device for rapidly increasing the power of a fiber laser provided in an embodiment of the present invention; Figure 2 A schematic diagram comparing the rise time of laser output power provided in an embodiment of the present invention.

[0022] Icons: 1. Laser body; 2. Power monitoring module; 3. Control module; 4. Drive module; 5. Power supply module; 6. Pump source assembly; 7. Laser output unit; 8. Optical power sensor; 9. Data acquisition circuit; 10. Microprocessor; 11. Algorithm logic unit; 12. Current driver; 13. Temperature controller; 14. DC power supply; 15. Filtering circuit. Detailed Implementation

[0023] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0024] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Example

[0026] Please refer to Figure 1 as well as Figure 2 A control device for rapidly increasing the power of a fiber laser, comprising: The laser body 1 includes a pump source assembly 6 and a laser output unit 7; the pump source assembly 6 includes a main pump source group and an auxiliary pump source group, and the laser output unit 7 includes a gain fiber, a transmission fiber, a resonant cavity for amplifying laser oscillation, and a cladding stripper for stripping cladding light. The power monitoring module 2 is used to collect the output power of the laser in real time, convert the collected power signal into an electrical signal, and transmit it to the control module 3; the power monitoring module 2 includes an optical power sensor 8 and a data acquisition circuit 9; Control module 3 is used to receive the power signal transmitted by power monitoring module 2, identify the current power range, and generate drive control signal; control module 3 includes microprocessor 10 and algorithm logic unit 11; The drive module 4 includes a current driver 12 and a temperature controller 13; the current driver 12 includes a constant current drive circuit board and a group drive unit; the constant current drive circuit board is used to realize linear soft start and constant current output; the group drive unit is used to switch drive modes and adjust the drive current of the pump source. The power supply module 5 is used to provide a stable operating power supply for the power monitoring module 2, the control module 3, the drive module 4, and the laser body 1.

[0027] Preferably, the pump source assembly 6 further includes an isolation unit for isolating the reverse ASE light and an AWL active wavelength locking unit for outputting stable pump light.

[0028] Preferably, the resonant cavity includes a high-reflectivity grating, a ytterbium-doped gain fiber, and a low-reflectivity grating.

[0029] Preferably, the constant current drive circuit includes a power control element MOSFET and an operational amplifier follower to control the reference voltage; The driving modes include conventional constant current driving mode, pre-compensated driving mode, and constant power driving mode.

[0030] Preferably, the power supply module 5 includes a DC power supply unit 14 and a filter circuit unit 15.

[0031] Preferably, the power monitoring module 2 is a high-speed power monitor, and the monitoring port of the high-speed power monitor is equipped with a filter. The power measurement range of the power monitoring module 2 is 0-1200W.

[0032] Preferably, the pump source assembly 6 includes at least three main pump source groups and at least two auxiliary pump source groups; Both the main pump source group and the auxiliary pump source group are composed of 976nm pump sources.

[0033] Preferably, the microprocessor 10 uses an ARM Cortex-M4 series chip with a main frequency of not less than 240MHz, which can quickly process power monitoring signals and generate drive control signals; The constant current drive circuit board adopts a parallel output of 4 sets of constant current circuits, which can accurately adjust the pump source drive current. The current adjustment accuracy of the constant current drive circuit board is not less than 0.1A, and the drive voltage range of the constant current drive circuit board is 0-48V.

[0034] A method for controlling the rapid increase of power in a fiber laser, specifically including the following steps: Step S100: The output power of the laser is collected in real time by the power monitoring module 2 to determine the current power range and complete the identification of power segments; The range includes a low power range and a high power range. The power is set to 1000W. The low power range corresponds to 0-900W (0% to 90%), and the high power range corresponds to 900-1000W (90% to 100%). In step S200, when it is detected that the current output power of the laser is in the low power range, the drive module 4 adopts the conventional constant current drive mode to control the pump source component 6 to output pump light, and drive the output power of the laser to rise from 0W to 900W with a rise time of 1ms. Through the AWL active wavelength locking unit, the pump light wavelength is kept stable in the range of 976±3nm. In step S300, when the current output power of the laser is detected to reach the set power of 900W, the system switches to the pre-compensation drive mode. The drive module 4 drives multiple 976nm pump sources in groups according to the preset power compensation parameters, namely, the main pump source group and the auxiliary pump source group. At the same time, the AWL active wavelength locking unit is activated. The main pump source group maintains the current drive current unchanged, while the auxiliary pump source group instantly increases the drive current to the preset threshold. The preset threshold is set according to the set power requirement to ensure that the pump light power output by the auxiliary pump source group can quickly compensate for the gain loss in the high power range. In step S400, while the pre-compensation drive mode is started, the power monitoring module 2 collects the laser output power in real time at a sampling frequency of 100MHz, compares the collected actual power with the preset power boost curve, and calculates the power deviation; according to the power deviation, the drive module 4 adjusts the drive current of the main pump source group and the auxiliary pump source group in real time through the PID negative feedback control algorithm, driving the laser power to rise rapidly from the set power of 900W to the set power of 1000W, with the rise time controlled within 2ms; In step S500, when the output power of the laser reaches the set power of 1000W, the drive module 4 switches to constant power drive mode. Combined with the real-time feedback of the power monitoring module 2, the pump source drive current is adjusted to maintain the laser output power stability, with the fluctuation range controlled within ±1%. At the same time, the pump light wavelength is continuously locked through the AWL active wavelength locking unit to complete the control of the laser power increase.

[0035] Preferably, in step S100, the high-speed power monitor acquires the output power of the laser in real time at a sampling frequency of 100MHz. The filter set at the monitoring port of the high-speed power monitor has a transmittance of ≥95% for signal light and ≤5% for pump light, and the signal light incident on the high-speed power monitor is within the power monitoring range of the high-speed power monitor. Herein, the signal light is the laser light after passing through the filter.

[0036] Preferably, in step S300, the main pump source group maintains the current drive current unchanged, and the current drive current is 10A; The preset threshold of the drive current is determined as follows: the gain and loss characteristics of the 1000W fiber laser in the 900-1000W power range are tested in advance, and the output power-drive current curve of the 976nm pump source is combined to determine that the preset threshold of the drive current of the auxiliary pump source group is 12A.

[0037] Preferably, in step S400, the power deviation is calculated using the following formula: ΔP(t)=Pref(t)-Pfb(t) Where ΔP(t) is the power deviation at time t; Pref(t) is the target power at time t; and Pfb(t) is the actual output power at time t.

[0038] Preferably, the PID negative feedback control algorithm adopts positional PID control, and its output is the adjustment of the pump source drive current, calculated as: u(t) = 0.8 * ΔP(t) + 0.03 * ∫ t o ΔP(t)dt+0.2*dΔP(t) / dt Where u(t) is the adjustment amount of the pump source drive current at time t; ∫t0ΔP(t)dt is the power deviation integral from when the laser's output power enters the 90% range (t=0) to the current time t, i.e., the cumulative past deviation.

[0039] Working principle of the invention: Research has revealed three main reasons for the slow rise in power in the 90%-100% power range: First, when the 976nm pump source is in the high-power range (close to the set power), the accumulation rate of inverted particles in the gain medium slows down, and gain saturation is prone to occur, thus hindering power increase. Second, traditional lasers use a single constant current drive mode, which cannot adjust the drive parameters in real time according to power feedback in the high-power range. The timing characteristics of pump light injection are unreasonable, which can easily cause excessive or insufficient accumulation of inverted particles, thus affecting the power rise rate. Third, there is a lack of effective power feedback adjustment mechanisms, which cannot accurately compensate for power loss in the high-power range. At the same time, traditional methods to suppress overshoot (such as increasing the substrate current) will bring safety hazards, while methods such as changing the length of the gain fiber and the reflectivity of the cavity mirror are difficult to implement in engineering.

[0040] This invention effectively solves the technical problem of excessively long rise time in the 90%-100% power range of a 1000W fiber laser composed of a 976nm pump source. By combining a group drive unit, a conventional constant current drive mode, a pre-compensation drive mode, and a constant power drive mode with PID negative feedback regulation of a PID controller (algorithm logic unit 11), the power range can be rapidly increased to the set power within 2ms. Compared with the 2 minutes of the prior art, the rise efficiency is improved by 6000 times, which greatly improves the working efficiency of the laser and adapts to the needs of rapid power switching in industrial processing scenarios.

[0041] The pre-compensation drive mode of the grouped drive unit (main pump source group and auxiliary pump source group) and its control, combined with the AWL active wavelength locking technology of the AWL active wavelength locking unit, accurately compensates for the gain loss in the high power range, while ensuring the stability of the pump light wavelength and avoiding damage to the pump source by the reverse ASE light. It effectively solves the problems of gain saturation and unreasonable accumulation of inversion particles in the high power range, and takes into account both the rapid rise of power and pump source protection.

[0042] Equipped with a PID controller and incorporating a PID negative feedback control algorithm, combined with real-time feedback from the power monitoring module 2, the drive current can be adjusted in real time according to power deviation. This prevents power overshoot or fluctuations, ensuring that the laser's output power stabilizes (fluctuation within ±1%) after rapidly rising to the set power. Furthermore, it eliminates the need for potentially hazardous methods such as increasing the substrate current, thus improving the laser's operational safety and reliability. The entire control method and device are simple in structure and easy to implement in engineering. They do not require changes to the laser's core structure (such as gain fiber length or cavity mirror reflectivity), enabling rapid power rise in the high-power range. The modification is simple and cost-effective, facilitating the upgrade and modification of existing 976nm pump-source 1000W fiber lasers, and have broad application prospects. In this embodiment, the power monitoring module 2 employs a high-speed sampling design and optimizes the monitoring position and filter structure to ensure the accuracy and timeliness of power acquisition in the high-power range. This provides a reliable basis for drive adjustment, further improving the accuracy and stability of power rise, while avoiding the problem of monitoring module saturation damage.

[0043] In this embodiment, the PID controller is the algorithm logic unit 11. The PID negative feedback control algorithm adopts positional PID control, and its output is the adjustment amount of the pump source drive current. The calculation formula is: u(t) = 0.8*ΔP(t) + 0.03*∫ t o ΔP(t)dt+0.2*dΔP(t) / dt Where u(t) is the pump source drive current adjustment at time t (unit: A); ΔP(t) is the power deviation at time t (the difference between the target power and the actual output power, unit: W); a proportional coefficient Kp=0.8 can be selected for fast response to power deviation, an integral coefficient Ki=0.03 for eliminating steady-state power deviation in the high power range, and a differential coefficient Kd=0.2 for predicting the trend of power deviation change and suppressing power overshoot. The three work together to ensure that the laser output power rises rapidly from 900W to 1000W without obvious overshoot, and the rise time is controlled within 2ms.

[0044] Specifically, in step S200, the conventional constant current driving mode is as follows: the pump source component 6 is controlled to output pump light, driving the output power of the laser to rise from 0 to 900W with a rise time of 1ms. The pump light wavelength is kept stable in the range of 976±3nm by the AWL active wavelength locking unit. In step S300, the pre-compensation drive mode is as follows: the drive module 4 drives multiple 976nm pump sources in groups according to the preset power compensation parameters, namely, the main pump source group and the auxiliary pump source group. At the same time, the AWL active wavelength locking unit is activated. The main pump source group maintains the current drive current unchanged, while the auxiliary pump source group instantly increases the drive current to the preset threshold. The preset threshold is set according to the set power requirements to ensure that the pump light power output by the auxiliary pump source group can quickly compensate for the gain loss in the high power range. In step S500, the constant power drive mode is as follows: combined with the real-time feedback of the power monitoring module 2, the pump source drive current is adjusted to maintain the stability of the laser output power, and the fluctuation range is controlled within ±1%. At the same time, the pump light wavelength is continuously locked through the AWL active wavelength locking unit to complete the control of the laser power increase.

[0045] In this embodiment, the laser body 1 includes five 976nm pump source components 6 and a laser output unit 7. The five 976nm pump sources are divided into three main pump source groups and two auxiliary pump source groups. All three main pump source groups and two auxiliary pump source groups are high-stability multimode pumped laser sources with built-in isolation units and AWL active wavelength locking units. The output wavelength of each 976nm pump source component 6 is 976±3nm, and the power of a single pump source is set to 200W, with the total output power matching the requirements of a 1000W fiber laser. The laser output unit 7 includes a gain fiber, a resonant cavity, a cladding light stripper, and a transmission fiber. The resonant cavity includes a high-reflection grating, a ytterbium-doped gain fiber, and a low-reflection grating, used to realize laser oscillation amplification. The cladding light stripper is used to strip the cladding light to ensure the purity of the output laser. The transmission fiber is used to transmit and output the laser.

[0046] The power monitoring module 2 uses a high-speed power monitor, which is located at the encapsulation output port of the cladding optical stripper. The monitoring port of the high-speed power monitor is equipped with a filter. The filter has a transmittance of ≥95% for signal light and ≤5% for pump light. The high-speed power monitor has a response time of 1µs, a power measurement range of 0-1200W, a measurement accuracy of ±0.5%, and a sampling frequency of 100MHz. It is used to collect the output power of the laser in real time, convert the collected power signal into an electrical signal, and transmit it to the control module 3.

[0047] Control module 3 includes a microprocessor 10 and a PID controller (algorithm logic unit 11). The microprocessor 10 uses an ARM Cortex-M4 series chip with a main frequency of 240MHz. It has a built-in preset linear power boost curve (slope 50W / ms) and power compensation parameters (preset threshold of 12A for auxiliary pump source group drive current). It is used to receive the power signal transmitted by the power monitoring module 2, identify the current power range, and generate drive control signals. The PID controller is integrated inside the microprocessor 10. The PID parameters can be adjusted online (proportional coefficient 0.8, integral coefficient 0.03, derivative coefficient 0.2). It can generate adjustment signals according to the power deviation to achieve precise control of the drive module 4.

[0048] Drive module 4 includes a current driver 12 and a temperature controller 13. The current driver 12 includes a constant current drive circuit board and a group drive unit. The constant current drive circuit board uses MOSFETs and operational amplifier followers to control the reference voltage. It adopts a parallel output mode of 4 groups of constant current circuits, with a current regulation accuracy of 0.1A and a drive voltage range of 0-48V, realizing linear soft start and constant current output. The group drive unit adopts an optocoupler isolation design and is used to drive the main pump source group and the auxiliary pump source group respectively. It can switch the drive mode (conventional constant current drive mode, pre-compensation drive mode, constant power drive mode) according to the drive control signal of the control module 3, and adjust the drive current of the main pump source group and the drive current of the auxiliary pump source group. The temperature controller 13 is used to keep the temperature of the main pump source group and the auxiliary pump source group constant at about 25℃.

[0049] Power supply module 5: adopts a switching power supply with an adjustable output voltage of 0-48V and an output current of 30A. It is used to provide a stable working power supply for power monitoring module 2, control module 3, drive module 4 and laser body 1, ensuring the normal operation of each module.

[0050] In this embodiment, when the control module 3 is working, the power monitoring module 2 collects the laser output power in real time. The control module 3 identifies the power range and generates a drive control signal. The drive module 4 switches the drive mode according to the drive control signal, realizing a rapid rise of the laser to the set power in the low power range (1ms) and in the high power range (2ms), while maintaining power stability. Testing shows that this device can effectively achieve a rapid rise of the 1000W fiber laser composed of a 976nm pump source within 2ms in the 90%-100% power range, with output power fluctuation ≤±1%, no obvious overshoot, and stable pump source operation, fully meeting the needs of industrial processing and other scenarios. Figure 1 In the image above, the arrows indicate the signal transmission directions from the laser body 1 to the control module 3, drive module 4, and power module 5, respectively. Figure 1 In the middle, the arrows in the middle transmit sequentially from left to right. The power output by the laser body 1 is collected by the power monitoring module 2, processed by the control module 3, and switched by the drive module 4, etc., in accordance with the control process of this application. Figure 1 In the diagram, the arrows at the bottom indicate the power transmission directions of the power module 5, which provides power to the drive module 4, control module 3, power monitoring module 2, and laser body 1. That is, the laser body 1 is electrically connected to the power monitoring module 2, control module 3, drive module 4, and power module 5.

[0051] This invention can improve laser output power while balancing rapid power rise and output stability, avoiding power overshoot or fluctuations that could damage laser components or affect processing quality. Experimental tests show that, on a 976nm pump-source fiber laser using this invention, the rise time in the 90-100% power range is reduced by over 99%, and the fluctuation amplitude is reduced by over 66%, significantly extending the pump source's lifespan.

[0052] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A control device for rapidly increasing the power of a fiber laser, characterized in that, include: The laser body includes a pump source assembly and a laser output unit; the pump source assembly includes a main pump source group and an auxiliary pump source group, and the laser output unit includes a gain fiber, a transmission fiber, a resonant cavity for amplifying laser oscillation, and a cladding stripper for stripping cladding light. A power monitoring module is used to collect the output power of the laser in real time, convert the collected power signal into an electrical signal, and transmit it to the control module; the power monitoring module includes an optical power sensor and a data acquisition circuit. The control module is used to receive the power signal transmitted by the power monitoring module, identify the current power range, and generate a drive control signal; the control module includes a microprocessor and an algorithm logic unit. The drive module includes a current driver and a temperature controller; the current driver includes a constant current drive circuit board and a group drive unit. The constant current drive circuit board is used to achieve linear soft start and constant current output; the group drive unit is used to switch drive modes and adjust the drive current of the pump source. The power supply module is used to provide a stable operating power supply for the power monitoring module, the control module, the drive module and the laser body.

2. The control device for rapid power increase of a fiber laser according to claim 1, characterized in that, The pump source assembly also includes an isolation unit for isolating the reverse ASE light and an AWL active wavelength locking unit for outputting stable pump light.

3. The control device for rapid power increase of a fiber laser according to claim 2, characterized in that, The resonant cavity includes a high-reflectivity grating, a ytterbium-doped gain fiber, and a low-reflectivity grating.

4. The control device for rapid power increase of a fiber laser according to claim 3, characterized in that, The constant current drive circuit includes a power control element MOSFET and an operational amplifier follower to control the reference voltage; The driving modes include conventional constant current driving mode, pre-compensation driving mode, and constant power driving mode.

5. The control device for rapid power increase of a fiber laser according to claim 4, characterized in that, The power module includes a DC power supply unit and a filter circuit unit.

6. The control device for rapid power increase of a fiber laser according to claim 5, characterized in that, The power monitoring module is a high-speed power monitor, and the monitoring port of the high-speed power monitor is equipped with a filter. The power measurement range of the power monitoring module is 0-1200W.

7. The control device for rapid power increase of a fiber laser according to claim 1, characterized in that, The pump source assembly includes at least three main pump source groups and at least two auxiliary pump source groups; Both the main pump source group and the auxiliary pump source group are composed of 976nm pump sources.

8. The control device for rapid power increase of a fiber laser according to claim 1, characterized in that, The microprocessor has a main frequency of no less than 240MHz and is capable of quickly processing power monitoring signals and generating drive control signals. The constant current drive circuit board adopts a parallel output of 4 sets of constant current circuits, which can accurately adjust the pump source drive current. The current adjustment accuracy of the constant current drive circuit board is not less than 0.1A, and the drive voltage range of the constant current drive circuit board is 0-48V.

9. A method for controlling the rapid increase of fiber laser power, comprising the control device for the rapid increase of fiber laser power as described in any one of claims 1-8, characterized in that, Specifically, the following steps are included: Step S100: The output power of the laser is collected in real time through the power monitoring module to determine the current power range and complete the identification of power segments; The range includes a low power range and a high power range. The power is set to 1000W. The low power range corresponds to 0-900W, and the high power range corresponds to 900-1000W. Step S200: When it is detected that the current output power of the laser is in the low power range, the drive module adopts the conventional constant current drive mode to control the pump source component to output pump light, and drives the output power of the laser to rise from 0W to 900W with a rise time of 1ms. Through the AWL active wavelength locking unit, the pump light wavelength is kept stable in the range of 976±3nm. Step S300: When the laser's current output power is detected to have reached the set power of 900W, switch to the pre-compensation drive mode. The drive module groups multiple 976nm pump sources into a main pump source group and an auxiliary pump source group according to the preset power compensation parameters. At the same time, the AWL active wavelength locking unit is activated. The main pump source group maintains the current drive current unchanged, while the auxiliary pump source group instantly increases the drive current to a preset threshold. The preset threshold is set according to the set power requirement to ensure that the pump light power output by the auxiliary pump source group can quickly compensate for the gain loss in the high power range. In step S400, while the pre-compensation drive mode is started, the power monitoring module collects the laser output power in real time at a sampling frequency of 100MHz, compares the collected actual power with the preset power boost curve, and calculates the power deviation. Based on the power deviation, the drive module adjusts the drive current of the main pump source group and the auxiliary pump source group in real time through the PID negative feedback control algorithm, driving the laser power to rise rapidly from the set power of 900W to the set power of 1000W, with the rise time controlled within 2ms. In step S500, when the output power of the laser reaches the set power of 1000W, the drive module switches to constant power drive mode. Combined with the real-time feedback of the power monitoring module, the pump source drive current is adjusted to maintain the laser output power stability, with the fluctuation range controlled within ±1%. At the same time, the pump light wavelength is continuously locked through the AWL active wavelength locking unit to complete the control of the laser power increase.

10. The method for controlling the rapid increase of power in a fiber laser according to claim 9, characterized in that, In step S100, the high-speed power monitor collects the output power of the laser in real time at a sampling frequency of 100MHz. The filter set at the monitoring port of the high-speed power monitor has a transmittance of ≥95% for signal light and a transmittance of ≤5% for pump light. The signal light is incident on the high-speed power monitor and is within the power monitoring range of the high-speed power monitor.

11. The method for controlling the rapid increase of power in a fiber laser according to claim 9, characterized in that, In step S300, the main pump source group maintains the current drive current unchanged, which is currently 10A; The preset threshold of the drive current is determined by the following method: the gain loss characteristics of the 1000W fiber laser in the 900-1000W power range are tested in advance, and the output power-drive current curve of the 976nm pump source is combined to determine that the preset threshold of the drive current of the auxiliary pump source group is 12A.

12. The method for controlling the rapid increase of power in a fiber laser according to claim 9, characterized in that, In step S400, the power deviation is calculated using the following formula: ΔP(t)=Pref(t)-Pfb(t) Where ΔP(t) is the power deviation at time t; Pref(t) is the target power at time t; and Pfb(t) is the actual output power at time t.

13. The method for controlling the rapid increase of power in a fiber laser according to claim 12, characterized in that, The PID negative feedback control algorithm adopts positional PID control, and its output is the adjustment of the pump source drive current. The calculation formula is: u(t) = 0.8*ΔP(t) + 0.03*∫ t o ΔP(t)dt+0.2*dΔP(t) / dt Where u(t) is the adjustment amount of the pump source drive current at time t; ∫t0ΔP(t)dt is the power deviation integral from when the laser's output power enters the 90% range (t=0) to the current time t, i.e., the cumulative past deviation.

Images