A laser control method, device and laser apparatus

Abstract

The application relates to the technical field of lasers, and particularly provides a laser control method and device and a laser equipment, the method comprising the following steps: acquiring a first light-on signal, a second light-on signal and a frequency signal; when the first light-on signal is high, setting a first current signal for a bias pump laser, so that the bias pump laser works in a low-duty-cycle modulation mode to pre-energize a fiber amplifier; during the pre-energizing of the fiber amplifier by the bias pump laser, acquiring a pulse frequency of a working pump laser; and according to the high and low of the pulse frequency and a current pulse corresponding set-off frequency, controlling the working pump laser to work in a pumping mode to energize the fiber amplifier. The bias pump laser is set to work in a low-duty-cycle modulation mode when pre-energizing the fiber amplifier, so that the influence of temperature on the low-power working condition of the pump laser is reduced, and the reliability of the laser is improved.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a laser control method, apparatus and laser equipment. Background Technology

[0002] In the MOPA pulsed fiber laser, a seed source laser outputs laser pulses, which are then amplified by multiple fiber amplifier stages to output high-energy laser pulses. Each fiber amplifier stage has a corresponding pump laser to provide pump energy. Control is primarily achieved through two signals controlling the switching of the pulse sequence: a pre-on signal and an on signal.

[0003] In existing technologies, each fiber amplifier stage corresponds to a pump laser. During pre-charging, the bias current is typically low, only slightly higher than the pump laser's threshold current. However, due to the inherent characteristics of the pump laser, the threshold current changes with the heat sink temperature. Therefore, the same bias current can result in significantly different output optical power, affecting the initial pulse height when the switching signal is activated, as well as the pulse energy when operating below the cutoff frequency, and potentially even causing laser failure. Furthermore, since the bias current and operating current are generated by the same drive circuit, the DAC (digital-to-analog converter) accuracy is insufficient to meet the fine-tuning requirements of the bias current. Summary of the Invention

[0004] In view of this, embodiments of this application provide a laser control method, apparatus, and laser device, which can effectively solve the problems of the influence of temperature changes on the laser and the influence of current changes on the charging effect.

[0005] In a first aspect, embodiments of this application provide a laser control method, including:

[0006] Acquire the first switching signal, the second switching signal, and the frequency signal;

[0007] When the first switching signal is high, a first current signal is set for the bias pump laser, so that the bias pump laser operates with a low duty cycle to precharge the fiber amplifier.

[0008] During the pre-charging of the fiber amplifier by the bias pump laser, the pulse frequency of the working pump laser is obtained;

[0009] Based on the pulse frequency and the cutoff frequency set for the current pulse, the working pump laser is controlled to pump the fiber amplifier to charge it.

[0010] In some embodiments, controlling the working pump laser to pump the fiber amplifier based on the cutoff frequency set according to the pulse frequency and the current pulse to charge the fiber amplifier includes:

[0011] If the pulse frequency is higher than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform continuous pumping to charge the fiber amplifier.

[0012] If the pulse frequency is lower than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform modulation pumping to charge the fiber amplifier.

[0013] In some embodiments, the first current signal is a current signal in which a first high current value and a first low current value are periodically changed according to a preset time.

[0014] The cycle time range is 2µs-5µs; the duty cycle is 5-30%.

[0015] The range of the first high current value is 5A-30A.

[0016] In some embodiments, controlling the working pump laser to perform continuous pumping operation includes:

[0017] When the second switching signal is detected to be high and the pulse frequency signal is higher than the cutoff frequency, a third current signal is set for the working pump laser, so that the working pump laser outputs a continuous pump light signal.

[0018] In some embodiments, controlling the working pump laser to perform modulation pumping includes:

[0019] When the second switching signal is detected to be high and the pulse frequency signal is lower than the cutoff frequency, a second current signal is set for the working pump laser, so that the working pump laser outputs a modulated pump light signal.

[0020] In some embodiments, the second current signal is a current signal in which a second high current value and a second low current value change periodically over a preset time.

[0021] Wherein, the second high current value is higher than the first high current value;

[0022] Within one cycle, the duration of the second high current value is equal to the reciprocal of the cutoff frequency.

[0023] In some embodiments, the second low current value is 0.

[0024] In some embodiments, the third current value of the third current signal is the same as the second high current value.

[0025] Secondly, embodiments of this application provide a laser control device, comprising:

[0026] The first acquisition module is used to acquire the first switching signal, the second switching signal, and the frequency signal;

[0027] The first control module is used to set a first current signal for the bias pump laser when the first switching signal is high, so that the bias pump laser is modulated with a low duty cycle to precharge the fiber amplifier.

[0028] The second acquisition module is used to acquire the pulse frequency of the working pump laser during the pre-charging of the fiber amplifier by the bias pump laser.

[0029] The second control module is used to control the working pump laser to pump the fiber amplifier according to the pulse frequency and the cutoff frequency set for the current pulse.

[0030] Thirdly, embodiments of this application provide a laser device, including: a seed laser, a multi-stage fiber amplifier, an optical output head, and a controller; each stage of the fiber amplifier is provided with a corresponding set of pump lasers; each set of pump lasers includes a bias pump laser and a working pump laser; the controller is connected to the seed laser, the multi-stage fiber amplifier, the bias pump laser, and the working pump laser; the seed laser, the bias pump laser, the working pump laser, and the optical output head are all connected to the fiber amplifier;

[0031] The seed source laser is used to output a seed source optical signal;

[0032] The fiber amplifier is used to amplify the seed source optical signal; wherein the pump optical signal is output through the bias pump laser and the working pump laser.

[0033] The bias pump laser is used to precharge the fiber amplifier. When the first switching signal is high, the bias pump laser operates in a narrow pulse width and low duty cycle modulation mode.

[0034] The controller is used to control the seed source laser to output a seed source light signal and control the working pump laser to continuously pump the fiber amplifier when the pulse frequency is higher than the cutoff frequency set for the current pulse and the second switching signal is detected to be high.

[0035] The controller is also configured to control the seed source laser to output a seed source light signal and control the working pump laser to perform modulation pumping operation to charge the fiber amplifier if the pulse frequency is lower than the cutoff frequency set for the current pulse and the second switching signal is detected to be high.

[0036] The optical output head is used to output the seed source optical signal amplified by the fiber amplifier.

[0037] The embodiments of this application have the following beneficial effects: This application uses a separate bias pump laser to pre-charge the fiber amplifier and a working pump laser to charge the fiber amplifier. By using both a bias pump laser and a working pump laser, and simultaneously using the bias pump laser to pre-charge the fiber amplifier with narrow pulse width and low duty cycle modulation, this application replaces the continuous pre-charging operation of the prior art. This significantly reduces the impact of temperature on the low-power operating conditions of the pump laser, ensuring the consistency of pulse characteristics of the laser, especially air-cooled lasers, under different ambient temperatures, thus improving laser reliability. Furthermore, the driving circuit of this application is also independent. This allows the driving circuit with the same DAC precision to improve the adjustment accuracy of the pre-charging power by two orders of magnitude, thereby improving the control accuracy of related performance. 。 Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, 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 this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of a laser pulse signal in the prior art is shown;

[0040] Figure 2 A schematic diagram of bias current operation in the prior art is shown;

[0041] Figure 3 A schematic diagram of the structure of a laser device according to an embodiment of this application is shown;

[0042] Figure 4 A first flowchart of a laser control method according to an embodiment of this application is shown;

[0043] Figure 5 A schematic diagram of the laser pulse signal according to an embodiment of this application is shown;

[0044] Figure 6 This paper shows a schematic diagram of the operation of the first current of the bias-pumped laser according to an embodiment of this application;

[0045] Figure 7 A schematic diagram of the structure of a laser control device according to an embodiment of this application is shown.

[0046] Explanation of key component symbols:

[0047] Seed source laser 110; fiber amplifier 120; bias pump laser 130; working pump laser 140; optical output head 150; laser control device 200; first acquisition module 210; first control module 220; second acquisition module 230; second control module 240. Detailed Implementation

[0048] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0049] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0050] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0052] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0053] like Figure 1 As shown, in the prior art, each fiber amplifier stage corresponds to a set of pump lasers. When the pre-switching signal is high, the pump laser enters a pre-charging state, operates with a low bias current, and outputs a small optical power to pre-charge the amplifier. When the switching signal is high, the seed laser outputs an optical pulse, and the pump laser operates with a higher operating current, outputting a larger optical power to charge the amplifier. Due to the pre-charging step, the first pulse of the pulse sequence can also be amplified, achieving the effect of "first pulse usable".

[0054] If the pulse frequency is higher than the cutoff frequency ( Figure 1 (Left side) When the switching signal is high, the pump laser is continuously pumped using the operating current. At this time, the average power remains constant, and the pulse energy decreases with the pulse frequency. If the pulse frequency is lower than the cutoff frequency ( Figure 1 (Right side) When the switching signal is high, the pump laser performs modulation pumping.

[0055] Therefore, the bias current set in the pump laser affects two aspects of its performance. First, the height of the initial pulse when the switching signal is first activated; a higher bias current results in a higher initial pulse. Second, the pulse energy when operating below the cutoff frequency; a higher bias current results in a higher pulse energy.

[0056] like Figure 2 As shown, in existing technologies, the bias current is typically low, only slightly higher than the pump laser's threshold current (0.5A-1A). However, due to its inherent characteristics, the threshold current of a pump laser changes with variations in the heat sink temperature. Therefore, the same bias current can result in significantly different optical power outputs, affecting the aforementioned performance aspects and potentially causing laser failure. Furthermore, since the bias current and operating current are generated by the same drive circuit, the accuracy of the DAC (digital-to-analog converter) is insufficient to meet the fine-tuning requirements of the bias current.

[0057] To address this, this application proposes a laser control method, apparatus, and laser device. By setting up a separate bias-pump laser and modulating it with a low duty cycle to pre-charge the fiber amplifier, the impact of temperature on the low-power operation of the pump laser is reduced. This ensures the consistency of pulse characteristics of the laser, especially air-cooled lasers, under different ambient temperatures, thus improving laser reliability. Furthermore, in existing technologies, the bias current and operating current are generated by the same drive circuit, and the DAC (digital-to-analog converter) accuracy is insufficient to meet the fine adjustment requirements of the bias current. This application, by setting up separate bias-pump lasers and operating pump lasers with separate drive circuits, allows for a two-order-of-magnitude improvement in the pre-charge power adjustment accuracy with the same DAC accuracy, thereby enhancing the overall performance control precision.

[0058] Before describing the embodiments of this application, let me first describe a laser device of this application, which is a MOPA pulsed fiber laser. Figure 3 As shown, the laser device includes: a seed source laser 110, a multi-stage fiber amplifier 120, and a controller (not shown in the figure); each stage of the fiber amplifier is equipped with a set of pump lasers, and each set of pump lasers includes a bias pump laser 130 and a working pump laser 140.

[0059] The seed source laser 110 is connected to the input end of the first-stage fiber amplifier 120 and is used to input the seed source optical signal to the fiber amplifier.

[0060] The fiber amplifier 120 is used to amplify the seed source optical signal; wherein the pump optical signal is output by the bias pump laser 130 and the working pump laser 140.

[0061] A bias-pumped laser 130, connected to the fiber amplifier 120, is used to control the bias-pumped laser 130 to turn on when the first switching signal is high, so that the bias-pumped laser 130 enters a pre-charge state, and sets a first current for the bias-pumped laser 130, so that the bias-pumped laser 130 operates with a narrow pulse width and low duty cycle to pre-charge the fiber amplifier 120.

[0062] The working pump laser 140 is connected to the fiber amplifier 120. When the pulse frequency is higher than the cutoff frequency set for the current pulse and the second switching signal is detected to be high, the controller controls the seed source laser 110 to output a seed source light signal and sets the working pump laser 140 to operate continuously, so as to charge the fiber amplifier 120.

[0063] The working pump laser 140 is also configured such that if the pulse frequency is lower than the cutoff frequency of the working pump laser 140 and the second switching signal is detected to be high, the controller controls the seed source laser 110 to output a seed source light signal and sets a second current for the working pump laser 140, so that the working pump laser 140 performs modulation pumping operation to charge the fiber amplifier 120.

[0064] An optical output head 150 is connected to the fiber optic amplifier 120 and is used to output the seed source optical signal amplified by the fiber optic amplifier 120.

[0065] The seed source laser 110, the multi-stage fiber amplifier 120, the bias pump laser 130, and the working pump laser 140 are all connected to the controller.

[0066] The laser control method will be described below with reference to some specific embodiments.

[0067] Figure 4 A schematic flowchart of a laser control method according to an embodiment of this application is shown.

[0068] Exemplarily, the laser control method includes the following steps:

[0069] Step S100: Obtain the first switching signal, the second switching signal, and the frequency signal.

[0070] The first switching signal is the switching signal of the bias pump laser, and the second switching signal is the switching signal of the working pump laser. The frequency signals include, but are not limited to, the pulse frequency of the working pump laser and the cutoff frequency set for the current pulse. The cutoff frequency is the frequency at which the set pulse operates at its maximum pulse energy under the nominal power, i.e., cutoff frequency = nominal power / maximum pulse energy for this pulse width. For example, for a 500W pump laser with a 200ns pulse width, the maximum pulse energy is 1mJ, and the corresponding cutoff frequency is 500W / 1mJ = 500kHz.

[0071] In step S200, when the first switching signal is high, a first current signal is set for the bias pump laser to enable the bias pump laser to operate with a low duty cycle for pre-charging the fiber amplifier.

[0072] Specifically, such as Figure 5 As shown, when the first switching signal is detected to be high, the bias pump laser is turned on, and a first current is set for the bias pump laser. The first current is a current that periodically changes between a first high current value and a first low current value according to a preset time. The time range of one cycle is 2us-5us, and the duty cycle is 5-30%. The duty cycle is the proportion of high current in one cycle.

[0073] Based on the first current set for the bias-pump laser, the bias-pump laser is modulated with a narrow pulse width and low duty cycle to enter the pre-charging state of the fiber amplifier. It should be noted that when a low pre-on signal is detected, the bias-pump laser is turned off, ending the pre-charging state; otherwise, the bias-pump laser remains in the pre-charging state of the fiber amplifier. This reduces the impact of temperature on the low-power operating conditions of the pump laser, ensuring the consistency of pulse characteristics of the laser, especially air-cooled lasers, under different ambient temperatures, and improving laser reliability.

[0074] Furthermore, the range of the first high current value is 5A-30A.

[0075] like Figure 6 As shown, this application modulates the bias pump laser with a narrow pulse width and low duty cycle, and the first high current value ranges from 5A to 30A, which is far from the threshold current of the pump laser (the threshold current is 0.5A to 1A). Compared with the DC drive in the prior art, this greatly reduces the impact of the change in the threshold current of the pump laser.

[0076] Step S300: During the pre-charging of the fiber amplifier by the bias pump laser, the pulse frequency of the working pump laser is obtained.

[0077] Step S400: Based on the pulse frequency and the cutoff frequency set for the current pulse, control the working pump laser to pump the fiber amplifier to charge it.

[0078] Specifically, if the pulse frequency is higher than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform continuous pumping to charge the fiber amplifier.

[0079] Specifically, to limit the laser pulse energy, MOPA pulsed lasers typically use different cutoff frequencies for different pulse widths, and the period corresponding to the cutoff frequency is used as the pump period for modulation pumping. For example... Figure 5(The left-side on-light signal corresponds to the high portion). At this time, the pulse frequency is higher than the cutoff frequency set for the current pulse, and when the second on-light signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to continuously pump to charge the fiber amplifier. At this time, the average output power of the laser remains unchanged, and the pulse energy decreases as the pulse frequency increases. When controlling the working pump laser to continuously pump, a third current signal (operating current) is set for the working pump laser, causing it to output a continuous pump light signal. The third current value of the third current signal is the same as the second high current value.

[0080] Furthermore, if the pulse frequency is lower than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform modulation pumping to charge the fiber amplifier.

[0081] Specifically, such as Figure 5 As shown (the right-hand side shows the high-signal portion), when the pulse frequency is lower than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform modulation pumping to charge the fiber amplifier. At this time, the average output power of the laser is lower than the nominal power, while the pulse energy remains unchanged.

[0082] When controlling the working pump laser to perform modulated pumping, a second current needs to be set for the working pump laser to output a modulated pump light signal. The second current is a current whose second high current value and second low current value change periodically according to a preset time interval; furthermore, the second high current value is higher than the first high current value, and the second high current value is typically the operating current. The second low current is 0.

[0083] Furthermore, within one cycle, the duration of the second high current is equal to the reciprocal of the cutoff frequency, that is, the duration of the second high current is the same as the period corresponding to the pulse cutoff frequency.

[0084] This application's fiber amplifier stage utilizes a bias pump laser and a working pump laser. By having the bias pump laser (single-chip) individually pre-charge the fiber amplifier, and by employing narrow pulse width and low duty cycle modulation during pre-charging, it replaces the continuous pre-charging operation of existing technologies. This significantly reduces the impact of temperature on the low-power operating conditions of the pump laser, ensuring the consistency of pulse characteristics of the laser, especially air-cooled lasers, under different ambient temperatures, thus improving laser reliability. Furthermore, in existing technologies, the pre-charging power is generated by DC driving a high-power pump laser (multi-chip) through a driver circuit; a small change in current corresponds to a large change in power. In this application, a separate bias pump laser (typically a single chip) is used, and modulation is achieved through a narrow pulse width and low duty cycle. With the same DAC precision driver circuit, the adjustment accuracy of the pre-charging power can be improved by two orders of magnitude, thereby enhancing the control accuracy of related performance. The pre-charging power adjustment is typically small, for example, 0-2W. In the background technology, the working pump and pre-charge pump are integrated, and are typically adjusted only within a range of less than 0.2A near the threshold current of the pump laser. However, this application can control a 2W power variation with a current adjustment range greater than 5A by using a low-power bias pump laser and low duty cycle modulation, thereby improving control accuracy.

[0085] Figure 7 A schematic diagram of a laser control device according to an embodiment of this application is shown. Exemplarily, the laser control device 200 includes:

[0086] The first acquisition module 210 is used to acquire the first switching signal, the second switching signal, and the frequency signal;

[0087] The first control module 220 is used to set a first current signal for the bias pump laser 130 when the first switching signal is high, so that the bias pump laser 130 is modulated with a low duty cycle to precharge the fiber amplifier 120.

[0088] The second acquisition module 230 is used to acquire the pulse frequency of the working pump laser during the pre-charging of the fiber amplifier 120 by the bias pump laser 130.

[0089] The second control module 240 is used to control the working pump laser 140 to perform pumping operation based on the pulse frequency and the cutoff frequency of the working pump laser 140, so as to charge the fiber amplifier 120.

[0090] It is understood that the device in this embodiment corresponds to the laser control method in the above embodiments, and the options in the above embodiments are also applicable to this embodiment, so they will not be described again here.

[0091] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that, in alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based device that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0092] In addition, the functional modules or units in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0093] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a smartphone, personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A laser control method, characterized in that, include: Acquire the first switching signal, the second switching signal, and the frequency signal; When the first switching signal is high, a first current signal is set for the bias pump laser, causing the bias pump laser to operate with a low duty cycle to pre-charge the fiber amplifier; wherein, the first current signal is a current signal in which a first high current value and a first low current value change periodically according to a preset time; one period ranges from 2us to 5us; the duty cycle is 5-30%; and the value range of the first high current value is 5A-30A; During the pre-charging of the fiber amplifier by the bias pump laser, the pulse frequency of the working pump laser is obtained; Based on the pulse frequency and the cutoff frequency set corresponding to the current pulse, the working pump laser is controlled to pump the fiber amplifier to charge it. The step of controlling the working pump laser to pump the fiber amplifier based on the cutoff frequency set according to the pulse frequency and the current pulse to charge the fiber amplifier includes: If the pulse frequency is higher than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform continuous pumping to charge the fiber amplifier. If the pulse frequency is lower than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform modulation pumping to charge the fiber amplifier.

2. The laser control method according to claim 1, characterized in that, The control of the working pump laser to perform continuous pumping operation includes: When the second switching signal is detected to be high, a third current signal is set for the working pump laser, so that the working pump laser outputs a continuous pump light signal.

3. The laser control method according to claim 2, characterized in that, The control of the working pump laser to perform modulation pumping includes: When the second switching signal is detected to be high, a second current signal is set for the working pump laser, so that the working pump laser outputs a modulated pump light signal.

4. The laser control method according to claim 3, characterized in that, The second current signal is a current signal in which the second high current value and the second low current value change periodically according to a preset time. Wherein, the second high current value is higher than the first high current value; Within one cycle, the duration of the second high current value is equal to the reciprocal of the cutoff frequency.

5. The laser control method according to claim 4, characterized in that, The second low current value is 0.

6. The laser control method according to claim 4, characterized in that, The third current value of the third current signal is the same as the second high current value.

7. A laser control device, characterized in that, include: The first acquisition module is used to acquire the first switching signal, the second switching signal, and the frequency signal; The first control module is used to set a first current signal for the bias pump laser when the first switching signal is high, so that the bias pump laser operates at a low duty cycle to pre-charge the fiber amplifier; wherein, the first current signal is a current signal in which a first high current value and a first low current value change periodically according to a preset time; one period ranges from 2us to 5us; the duty cycle is 5-30%; and the value range of the first high current value is 5A-30A. The second acquisition module is used to acquire the pulse frequency of the working pump laser during the pre-charging of the fiber amplifier by the bias pump laser. The second control module is used to control the working pump laser to perform pumping operation according to the pulse frequency and the cutoff frequency set corresponding to the current pulse, so as to charge the fiber amplifier. The step of controlling the working pump laser to pump the fiber amplifier based on the cutoff frequency set according to the pulse frequency and the current pulse to charge the fiber amplifier includes: If the pulse frequency is higher than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform continuous pumping to charge the fiber amplifier. If the pulse frequency is lower than the cutoff frequency set for the current pulse, and the second switching signal is high, the seed source laser is controlled to output a seed source light signal, and the working pump laser is controlled to perform modulation pumping to charge the fiber amplifier.

8. A laser device, characterized in that, include: Seed source laser, multi-stage fiber amplifier, optical output head and controller; Each stage of the fiber amplifier is equipped with a corresponding set of pump lasers; Each group of pump lasers includes a bias pump laser and a working pump laser; the controller is connected to the seed source laser, the multi-stage fiber amplifier, the bias pump laser, and the working pump laser; the seed source laser, the bias pump laser, the working pump laser, and the optical output head are all connected to the fiber amplifier. The seed source laser is used to output a seed source optical signal; The fiber amplifier is used to amplify the seed source optical signal; The bias pump laser is used to pre-charge the fiber amplifier. When the first switching signal is high, a first current signal is set for the bias pump laser, causing the bias pump laser to operate with a low duty cycle to pre-charge the fiber amplifier. The first current signal is a current signal that periodically changes between a first high current value and a first low current value according to a preset time interval; one period ranges from 2µs to 5µs; the duty cycle is 5-30%; and the first high current value ranges from 5A to 30A. The controller is used to control the seed source laser to output a seed source light signal and control the working pump laser to continuously pump the fiber amplifier when the pulse frequency is higher than the cutoff frequency set for the current pulse and the second switching signal is detected to be high. The controller is also configured to control the seed source laser to output a seed source light signal and control the working pump laser to perform modulation pumping operation to charge the fiber amplifier if the pulse frequency is lower than the cutoff frequency set for the current pulse and the second switching signal is detected to be high. The optical output head is used to output the seed source optical signal amplified by the fiber amplifier.

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