An adaptive wide temperature range air-cooled fiber laser and control method

Abstract

An adaptive wide temperature range air-cooled optical fiber laser and control method, including a shell, the shell is equipped with first pump module, second pump module, control module, first current drive module and second current drive module, first current drive module is connected with first pump module, second current drive module is connected with second pump module, the shell side is equipped with laser gain cavity, the shell one side is equipped with first fan and second fan, the shell other side is equipped with first air-cooled heat sink and second air-cooled heat sink, laser gain cavity is connected with first pump module and second pump module respectively, first fan, second fan, first pump module, second pump module, first current drive module and second current drive module are connected with control module, and laser gain cavity is connected with optical fiber cladding light filter.The pump light conversion rate is improved by controlling temperature environment.

Description

Technical Field

[0001] This invention relates to a fiber laser, specifically an adaptive wide-temperature-range air-cooled fiber laser and its control method. Background Technology

[0002] Fiber lasers have seen rapid development in recent years due to their numerous advantages. In particular, compact and lightweight direct-air-cooled (or forced-air-cooled) fiber lasers have been widely used in miniaturized fiber laser applications. This is because laser systems based on direct-air-cooled fiber lasers, such as those used for welding and cutting, do not require compressors or other cooling systems during operation. However, current direct-cooled fiber lasers use 915nm waveband pump sources, and the conversion efficiency from pump light to laser light is generally only 60-70%. Even with high-efficiency pump source modules with an electro-optical conversion efficiency of 50%-55%, the conversion efficiency from electrical energy to laser energy is only 25-35%. According to the principle of energy conservation, under the same laser output power, these lasers generate more heat, put more pressure on the cooling system, and produce more noise; similarly, under the same cooling conditions, these lasers are more prone to degradation.

[0003] Although fiber laser systems have achieved pump light conversion efficiencies exceeding 80% in recent years using 976nm wavelength pump sources, the narrow absorption range of the active fiber for 976nm and the significant fluctuations in output wavelength with temperature and current during pump source operation make it difficult to maintain output efficiency across various temperature ranges. This means that directly air-cooled fiber lasers without an uncooled system cannot utilize conventional 976nm wavelength pump sources. In summary, current lasers exhibit relatively low pump light conversion rates, hindering their full utilization. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an adaptive wide-temperature-range air-cooled fiber laser.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An adaptive wide-temperature-range air-cooled fiber laser includes a housing. Inside the housing are a first pump module, a second pump module, a control module, a first current-driven module, and a second current-driven module. The first current-driven module is connected to the first pump module, and the second current-driven module is connected to the second pump module. A laser gain cavity is located on the side of the housing. A first fan and a second fan are located on one side of the housing, and a first air-cooled heat sink and a second air-cooled heat sink are located on the other side of the housing. The first fan, the first pump module, and the first air-cooled heat sink are arranged in a straight line, as are the second fan, the second pump module, and the second air-cooled heat sink. The laser gain cavity is connected to both the first and second pump modules. The first fan, the second fan, the first pump module, the second pump module, the first current-driven module, and the second current-driven module are all connected to the control module. An optical fiber cladding filter is connected to the laser gain cavity.

[0007] Both the first pump module and the second pump module are connected to pump temperature sensors. Both the first air-cooled heat sink and the second air-cooled heat sink are connected to heat sink temperature sensors. The fiber optic cladding optical filter is connected to a photosensitive sensor. The pump temperature sensor, the heat sink temperature sensor, and the photosensitive sensor are all connected to the control module. The control module is also connected to an ambient temperature sensor.

[0008] The first pump module and the second pump module have different wavelengths, and the pump power redundancy of the first pump module is at least 25%, and the pump power redundancy of the second pump module is at least 10%.

[0009] The laser gain cavity uses ytterbium-doped fiber with a length of 33 meters or more as the active fiber.

[0010] The wavelengths of the first and second pump modules are linearly positively correlated with the operating temperature, with a drift of 0.31 nm / ℃. For every 1℃ increase in temperature, the wavelength increases by 0.31 nm; for every 1℃ decrease in temperature, the wavelength decreases by 0.31 nm.

[0011] A control method for an adaptive wide-temperature-range air-cooled fiber laser includes the following steps:

[0012] The system monitors the ambient temperature around the laser, as well as the real-time temperatures of the first and second pump modules. Based on the ambient temperature, it controls the output laser power of the first and second pump modules to operate individually or together. By comparing the detected real-time temperature with the set temperature, it controls the drive current, adjusts the output power of the first and second pump modules, and controls the airflow of the first and second fans.

[0013] When the ambient temperature is detected to be below 10°C and the output laser power of the laser is set to be below 50% of the rated power, the first pump module is turned off and the second pump module is started.

[0014] The control module only controls the current value output by the second current drive module, contributing drive current to the second pump module;

[0015] The temperature of the second pump module is detected in real time. This temperature represents the temperature of the pump chip inside the second pump module. The real-time temperature change value TΔ of the internal pump chip is obtained. The wavelength drift LΔ of the pump chip inside the second pump module is obtained by the following formula.

[0016] LΔ≈0.31×TΔ,(2)

[0017] 0.31 is the drift coefficient;

[0018] At this point, Pout≈P B ×PCE B (3)

[0019] Where Pout is the set output laser power, P B It is the output power of the second pump module, PCE B It is the conversion efficiency (PCE) of the pump light to laser light in the second pump module. B The PCE will change with the wavelength shift LΔ of the output pump light from the second pump module. According to equation (2), the PCE B It changes with the collected temperature change value TΔ.

[0020] Set the PCE corresponding to the wavelength shift LΔ B PCE corresponding to different TΔ values ​​was calculated experimentally in increments of 1℃. B For the second pump module:

[0021] TΔ B =|TBG-TB| (4)

[0022] Wherein, TBG=45-50℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the second pump module falls to 974-977nm, and TB is the temperature data collected in real time from the second pump module.

[0023] The control module uses the known set output laser power Pout and the temperature change value TΔ B Corresponding PCE B Calculate the current output power of the second pump module;

[0024] The output power Ppump of the second pump module and the input current I have the following approximate linear relationship:

[0025] Ppump≈I×(KJ)(5)

[0026] K is the pump power value per unit current, and J is the start-up current;

[0027] The control module dynamically adjusts the current value of the second pump module based on the temperature data TB collected from the second pump module.

[0028] The control module starts the second fan to keep the difference between the current temperature of the second pump module and the temperature TBG within the set range, so that the half-width range of the superimposed emission spectrum of the pump source chip inside the second pump module falls between 974-977nm.

[0029] When the ambient temperature is below 10℃ and the output laser power of the laser is set to be 50% higher than the rated power, the first pump module and the second pump module will start simultaneously. The laser will be pumped by both the first and second pump modules. At this time:

[0030] Pout≈PB×PCE B +PA×PCE A (6)

[0031] PCE A This refers to the conversion efficiency of the pump light to laser light from the first pump module. The control module sets the portion of the output laser power less than 50% to be contributed by the second pump module 3B, and the portion of the output laser power greater than 50% to be contributed by the first pump module. For the first pump module:

[0032] TΔA=|TAG-TA| (7)

[0033] Where TAG = 55-50℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the first pump module falls to 974-977nm, and TA is the temperature data collected in real time for the first pump module.

[0034] When the ambient temperature is between 10℃ and 30℃, the first pump module and the second pump module have the same contribution weight to the total pump power of the laser, each accounting for half.

[0035] Pout≈2×(PB×PCE B )≈2×(PA×PCE A (7)

[0036] When the ambient temperature is 30℃-45℃, the contribution weight of the first pump module to the total pump power of the laser is increased, and the contribution weight of the second pump module to the total pump power of the laser is decreased; specifically, the contribution weight of the first pump module to the total pump power of the laser is 660%, and the contribution weight of the second pump module to the total pump power of the laser is 40%.

[0037] A fiber cladding tube filter is connected to the output end of the laser gain cavity. The cladding light at the front and rear ends of the fiber cladding tube filter is detected and collected. The difference between the cladding light at the front and rear ends of the fiber cladding tube filter is set as PDΔ. This difference PDΔ is positively correlated with the proportion of cladding light that is not absorbed in the laser gain cavity. The standard deviation PDΔG is set.

[0038] If the difference between the detected PDΔ and PDΔG is greater than half of the PDΔG value, the first and second fans are controlled to reduce their speeds until the difference between PDΔ and PDΔG is less than half of the PDΔG value, at which point the first and second fans resume their original speeds.

[0039] The air volume is adjusted by controlling the speed of the first and second fans through the differential PDΔ.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] By controlling the temperature of each pump module and adjusting the airflow of the fan, the temperature is kept within an optimal range, improving the pump light conversion efficiency to 82-86, without causing an overheated environment, reducing the risk of damage, and extending the service life. Attached Figure Description

[0042] Figure 1 This is a cross-sectional structural diagram of the present invention;

[0043] Figure 2 This is a schematic diagram illustrating the connection principle of the present invention. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0045] In the description of this invention, it should be understood that if terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are used to 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 the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0047] like Figure 1 and 2As shown, an adaptive wide-temperature-range air-cooled fiber laser includes a housing. Inside the housing are a first pump module 31, a second pump module 32, a control module 1, a first current drive module 21, and a second current drive module 22. The first current drive module 21 is connected to the first pump module 31, and the second current drive module 22 is connected to the second pump module 32. A laser gain cavity is provided on the side of the housing. A first fan 51 and a second fan 52 are provided on one side of the housing, and a first air-cooled heat sink 41 and a second air-cooled heat sink 42 are provided on the other side of the housing. The first fan, the first pump module, and the first air-cooled heat sink are arranged in the same straight line direction. The second fan, the second pump module, and the second air-cooled heat sink are also arranged in the same straight line direction. The laser gain cavity is connected to the first pump module and the second pump module respectively. The first fan, the second fan, the first pump module, the second pump module, the first current drive module, and the second current drive module are all connected to the control module. An optical fiber cladding filter is connected to the laser gain cavity. The first fan primarily provides cooling for the first pump module and the first current drive module, while the second fan primarily provides cooling for the second pump module and the second current drive module. A control module regulates the speed of both fans, thus controlling the airflow; higher speeds result in greater airflow, and lower speeds in smaller airflow. This allows the fiber laser to dynamically adapt in real-time, meeting user-defined power settings while maintaining high electro-optical conversion efficiency across a wider ambient temperature range.

[0048] Both the first pump module 31 and the second pump module 32 are connected to pump temperature sensors. Both the first and second air-cooled heat sinks are connected to heat sink temperature sensors. The fiber optic cladding filter is connected to a photosensitive sensor. The pump temperature sensors, heat sink temperature sensors, and photosensitive sensors are all connected to the control module, which is also connected to an ambient temperature sensor. Through these sensors, the temperature can be acquired in real time. The temperature acquired by the pump temperature sensor can be approximately represented as the temperature of the internal pump chip. The ambient temperature sensor 9 is installed at the laser's air inlet, enabling more accurate acquisition of the ambient temperature.

[0049] Generally, direct air-cooled fiber lasers, to consider stability and lifespan, will have a pump power margin of approximately 10%-15%. For fiber lasers with the same rated output power Pout and the same total pump power Pi, the pump source module of the fiber laser provided in this application can have a higher pump power redundancy δ.

[0050] The total power Pi of the pump module is related to the rated output power Pout of the laser by the following formula:

[0051] Pout≈Pi×(1—δ)×PCE(1)

[0052] The manufacturing cost of a laser is largely positively correlated with the total pump light power; the higher the total pump light power, the higher the manufacturing cost. As shown in the above relationship, although this application increases the pump power redundancy δ, it does not significantly increase the total pump light power. Therefore, the manufacturing cost of the laser provided in this application will not increase significantly. This means that the solution provided in this application can improve reliability by substantially increasing the pump power redundancy without significantly increasing manufacturing costs.

[0053] The laser gain cavity uses conventional ytterbium-doped fiber (YDF) with a length of at least 33m as the active fiber. Typically, the absorption characteristics of YDF fiber determine that the laser gain cavity has the optimal absorption rate for laser light emitted from the pump source with wavelengths between 974 and 977 nm, enabling the pump light to achieve the target conversion efficiency (PCE) for laser light. This application uses a sufficient length of YDF, which can reduce the impact of the pump light wavelength shift LΔ on the PCE to a certain extent.

[0054] The pump source chips inside the first and second pump source modules used in this application have the following characteristics: the wavelength of the pump source chip changes linearly and positively with the operating temperature, with a drift of 0.31 nm / ℃. For every 1℃ increase in temperature, the wavelength increases by 0.31 nm; for every 1℃ decrease in temperature, the wavelength decreases by 0.31 nm.

[0055] The first pump module and the second pump module have different wavelengths, and the pump power redundancy of the first pump module is at least 25%, and the pump power redundancy of the second pump module is at least 10%.

[0056] In addition, this invention discloses a control method for an adaptive wide-temperature-range air-cooled fiber laser, comprising the following steps:

[0057] The system monitors the ambient temperature around the laser, as well as the real-time temperatures of the first and second pump modules. Based on the ambient temperature, it controls the output laser power of the first and second pump modules to operate individually or together. By comparing the detected real-time temperature with the set temperature, it controls the drive current, adjusts the output power of the first and second pump modules, and controls the airflow of the first and second fans.

[0058] For directly air-cooled fiber lasers that rely on forced air cooling by fans, the operating temperatures of the pump chips in the first and second pump modules are related to the ambient temperature, the heat dissipation capacity of the cooling system, and the operating current of the pump chips. The ambient temperature determines the base temperature, while the heat dissipation capacity of the cooling system and the operating current of the pump source chips determine the temperature rise. The operating temperature of the pump source chips is approximately equal to the sum of the base temperature and the temperature rise. Since the pump source contains a large number of pump source chips connected in series, the current is equal at every point, meaning the heat generated by all pump chips is approximately the same. Under identical heat dissipation conditions, the temperature rise of the pump chips in most locations within the pump source is the same. Therefore, a single temperature sampling point can be set on both the first and second pump modules to approximately characterize the temperature of the pump source chips. The real-time temperature collected by the pump module temperature sensor is linearly correlated with the temperature of the pump source chips.

[0059] The laser gain cavity absorbs the pump light emitted by the two pump modules and converts it into a final laser beam of 1070±10nm. The ytterbium-doped fiber (YDF) in the laser gain cavity has the best absorption rate for laser beams between 974 and 977nm.

[0060] The temperature TAG of the pump source chip inside the first pump module when the half-width range of the emitted spectrum after superposition falls to 974-977nm is 55-60℃; the temperature TBG of the pump source chip inside the second pump module when the half-width range of the emitted spectrum after superposition falls to 974-977nm is 45-50℃; obviously, under the same temperature conditions, the wavelength of the second pump module is larger.

[0061] Therefore, the real-time temperature change value TΔ collected by the temperature sensors of the two pump modules can be used to approximately reflect the wavelength shift LΔ of the pump source chip.

[0062] LΔ≈0.31×TΔ;(2)

[0063] As a directly air-cooled fiber laser that relies on forced air cooling by fans, the ambient temperature determines the base temperature of the first and second pump modules. The heat dissipation capacity of the cooling system consisting of two air-cooled heat sinks and two fans, as well as the operating current of the pump source chips inside the first and second pump modules, determine the temperature rise. Based on these characteristics, the directly air-cooled fiber laser described in this application can easily raise the operating temperature of the first and second pump modules above the ambient temperature, but it cannot raise the operating temperature of the two pump modules below the ambient temperature. Therefore, this application prioritizes a 45°C temperature environment for the selection of pump source modules and the heat dissipation capacity of the cooling system.

[0064] The first pump module and the second pump module have different wavelengths, and the pump power redundancy of the first pump module is at least 25% and the pump power redundancy of the second pump module is at least 10%. By reserving sufficient pump power redundancy, the pump source module will not release all power redundancy even when operating at maximum rated power.

[0065] When the ambient temperature is detected to be below 10°C and the output laser power of the laser is set to be below 50% of the rated power, the first pump module is turned off and the second pump module is started.

[0066] The control module only controls the current value output by the second current drive module, contributing drive current to the second pump module.

[0067] The temperature of the second pump module is detected in real time. This temperature represents the temperature of the pump chip inside the second pump module. The real-time temperature change value TΔ of the internal pump chip is obtained. The wavelength drift LΔ of the pump chip inside the second pump module is obtained by the following formula.

[0068] LΔ≈0.31×TΔ,(2)

[0069] 0.31 is the drift coefficient;

[0070] At this point, Pout≈P B ×PCE B (3)

[0071] Where Pout is the set output laser power, P B It is the output power of the second pump module, PCE B It is the conversion efficiency (PCE) of the pump light to laser light in the second pump module. B The PCE will change with the wavelength shift LΔ of the output pump light from the second pump module. According to equation (2), the PCE B It changes with the collected temperature change value TΔ.

[0072] Set the PCE corresponding to the wavelength shift LΔ B PCE corresponding to different TΔ values ​​was calculated experimentally in increments of 1℃. B For the second pump module:

[0073] TΔ B =|TBG-TB| (4)

[0074] Wherein, TBG=45-50℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the second pump module falls to 974-977nm, and TB is the temperature data collected in real time from the second pump module.

[0075] The control module uses the known set output laser power Pout and the temperature change value TΔ B Corresponding PCE B Calculate the current output power of the second pump module;

[0076] The output power Ppump of the second pump module and the input current I have the following approximate linear relationship:

[0077] Ppump≈I×(KJ)(5)

[0078] K is the pump power value per unit current, and J is the start-up current;

[0079] The control module dynamically adjusts the current value of the second pump module based on the temperature data TB collected from the second pump module.

[0080] The control module starts the second fan to maintain the difference between the current temperature of the second pump module and the temperature TBG within the set range, so that the half-width range of the emitted spectrum of the pump source chip inside the second pump module falls between 974-977nm, so that the laser has the best pump light conversion efficiency.

[0081] When the ambient temperature is below 10℃ and the output laser power of the laser is set to be 50% higher than the rated power, the first pump module and the second pump module will start simultaneously. The laser will be pumped by both the first and second pump modules. At this time:

[0082] Pout≈PB×PCE B +PA×PCE A (6)

[0083] PCE A This refers to the conversion efficiency of the pump light to laser light from the first pump module. The control module sets the portion of the output laser power less than 50% to be contributed by the second pump module 3B, and the portion of the output laser power greater than 50% to be contributed by the first pump module. For the first pump module:

[0084] TΔA=|TAG-TA| (7)

[0085] Where TAG = 55-50℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the first pump module falls to 974-977nm, and TA is the temperature data collected in real time for the first pump module.

[0086] When the ambient temperature is between 10℃ and 30℃, the first pump module and the second pump module have the same contribution weight to the total pump power of the laser, each accounting for half.

[0087] Pout≈2×(PB×PCE B )≈2×(PA×PCE A (7)

[0088] When the ambient temperature is 30℃-45℃, the contribution weight of the first pump module to the total pump power of the laser is increased, and the contribution weight of the second pump module to the total pump power of the laser is decreased; specifically, the contribution weight of the first pump module to the total pump power of the laser is 660%, and the contribution weight of the second pump module to the total pump power of the laser is 40%.

[0089] A fiber cladding tube filter is connected to the output end of the laser gain cavity. The cladding light at the front and rear ends of the fiber cladding tube filter is detected and collected. The difference between the cladding light at the front and rear ends of the fiber cladding tube filter is set as PDΔ. This difference PDΔ is positively correlated with the proportion of cladding light that is not absorbed in the laser gain cavity. The standard deviation PDΔG is set.

[0090] If the difference between the detected PDΔ and PDΔG is greater than half of the PDΔG value, the first and second fans are controlled to reduce their speeds until the difference between PDΔ and PDΔG is less than half of the PDΔG value, at which point the first and second fans resume their original speeds. The airflow is adjusted by controlling the speeds of the first and second fans based on the difference PDΔ.

[0091] For fiber lasers, the main function of the fiber cladding optical filter (CPS) is to filter out residual pump light that has not been completely absorbed by the YDF fiber at the laser output. Clearly, this creates a self-feedback mechanism: the lower the temperature, the greater the shift in the pump source output wavelength. Under the same power conditions, more pump light is filtered out by the CPS, leading to a rapid increase in CPS heat generation. This, in turn, rapidly raises the temperature of the pump source module, causing the pump light to move closer to the optimal absorption range of the YDF fiber. Then, the heat generation of the CPS gradually decreases.

[0092] Compared with existing general direct-air-cooled fiber lasers, this application, through the above method, can improve the photo-optical conversion efficiency of the pump light to laser light in a direct-air-cooled fiber laser to 82-86%; correspondingly, the electro-optical conversion efficiency is improved from 25-30% to 40-45%.

[0093] Therefore, by adjusting the different operating parameters of the first and second pump modules under different ambient temperatures, the laser can always be kept under conditions of optimal pump light conversion efficiency.

[0094] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive wide-temperature-range air-cooled fiber laser, characterized in that, The device includes a housing, within which are housed a first pump module, a second pump module, a control module, a first current drive module, and a second current drive module. The first current drive module is connected to the first pump module, and the second current drive module is connected to the second pump module. A laser gain cavity is located on the side of the housing. A first fan and a second fan are located on one side of the housing, and a first air-cooled heat sink and a second air-cooled heat sink are located on the other side of the housing. The first fan, the first pump module, and the first air-cooled heat sink are arranged in a straight line, as are the second fan, the second pump module, and the second air-cooled heat sink. The laser gain cavity is connected to the first pump module and the second pump module, respectively. The first fan, the second fan, the first pump module, the second pump module, the first current drive module, and the second current drive module are all connected to the control module. An optical fiber cladding optical filter is connected to the laser gain cavity, and a photosensitive sensor is connected to the optical fiber cladding optical filter. The photosensitive sensor is connected to the control module. A fiber cladding light filter is connected to the output end of the laser gain cavity. The cladding light at the front and back ends of the fiber cladding light filter is detected and collected. The difference between the cladding light at the front and back ends of the fiber cladding light filter is set as PDΔ. The difference PDΔ is positively correlated with the proportion of cladding light that is not absorbed in the laser gain cavity. The standard deviation PDΔG is set. If the difference between the detected PDΔ and PDΔG is greater than 1 / 2 of the PDΔG value, the first and second fans are controlled to reduce their speeds until the difference between PDΔ and PDΔG is less than 1 / 2 of the PDΔG value, at which point the first and second fans resume their original speeds. The air volume is adjusted by controlling the speed of the first and second fans through the differential PDΔ.

2. The adaptive wide-temperature-range air-cooled fiber laser according to claim 1, characterized in that, Both the first pump module and the second pump module are connected to a pump temperature sensor, and both the first air-cooled heat sink and the second air-cooled heat sink are connected to a heat sink temperature sensor. The pump temperature sensor and the heat sink temperature sensor are connected to the control module, and the control module is also connected to an ambient temperature sensor.

3. The adaptive wide-temperature-range air-cooled fiber laser according to claim 1, characterized in that, The first pump module and the second pump module have different wavelengths, and the pump power redundancy of the first pump module is at least 25%, and the pump power redundancy of the second pump module is at least 10%.

4. The adaptive wide-temperature-range air-cooled fiber laser according to claim 1, characterized in that, The laser gain cavity uses ytterbium-doped fiber with a length of 33 meters or more as the active fiber.

5. The adaptive wide-temperature-range air-cooled fiber laser according to claim 1, characterized in that, The wavelengths of the first and second pump modules are linearly positively correlated with the operating temperature, with a drift of 0.31 nm / ℃. For every 1℃ increase in temperature, the wavelength increases by 0.31 nm; for every 1℃ decrease in temperature, the wavelength decreases by 0.31 nm.

6. A control method for an adaptive wide-temperature-range air-cooled fiber laser according to any one of claims 2-5, characterized in that, Includes the following steps: The system monitors the ambient temperature around the laser, as well as the real-time temperatures of the first and second pump modules. Based on the ambient temperature, it controls the output laser power of the first and second pump modules to operate individually or together. By comparing the detected real-time temperature with the set temperature, it controls the drive current, adjusts the output power of the first and second pump modules, and controls the airflow of the first and second fans.

7. The control method for an adaptive wide-temperature-range air-cooled fiber laser according to claim 6, characterized in that, When the ambient temperature is detected to be below 10°C and the output laser power of the laser is set to be below 50% of the rated power, the first pump module is turned off and the second pump module is started. The control module only controls the current value output by the second current drive module, contributing drive current to the second pump module; The temperature of the second pump module is detected in real time, which represents the temperature of the pump chip inside the second pump module. The real-time temperature change value TΔ of the pump chip inside the second pump module is obtained, and the wavelength drift LΔ of the pump chip inside the second pump module is obtained by the following formula. LΔ≈0.31×TΔ, (2) 0.31 is the drift coefficient; At this point, Pout≈P B ×PCE B (3) Where Pout is the set output laser power, P B It is the output power of the second pump module, PCE B It is the conversion efficiency (PCE) of the pump light to laser light in the second pump module. B The PCE will change with the wavelength shift LΔ of the output pump light from the second pump module. According to equation (2), the PCE B It changes with the collected temperature change value TΔ.

8. The control method for an adaptive wide-temperature-range air-cooled fiber laser according to claim 7, characterized in that, Set the PCE corresponding to the wavelength shift LΔ B PCE corresponding to different TΔ values ​​was calculated experimentally in increments of 1℃. B For the second pump module: TΔ B =|TBG -TB| (4) Wherein, TBG=45~50℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the second pump module falls to 974~977nm, and TB is the temperature data collected in real time from the second pump module. The control module uses the known set output laser power Pout and the temperature change value TΔ B Corresponding PCE B Calculate the current output power of the second pump module; The current output power Ppump and input current I of the second pump module have the following approximate linear relationship: Ppump≈K×(IJ) (5) K is the pump power value per unit current, and J is the start-up current; The control module dynamically adjusts the current value of the second pump module based on the temperature data TB collected from the second pump module. The control module starts the second fan to keep the difference between the current temperature of the second pump module and the temperature TBG within the set range, so that the half-width range of the superimposed emission spectrum of the pump source chip inside the second pump module falls between 974 and 977 nm.

9. The control method for an adaptive wide-temperature-range air-cooled fiber laser according to claim 8, characterized in that, When the ambient temperature is below 10℃ and the output laser power of the laser is set to be 50% higher than the rated power, the first pump module and the second pump module will start simultaneously. The laser will be pumped by both the first and second pump modules. At this time: Pout≈P B ×PCE B +P A ×PCE A (6) PCE A This refers to the conversion efficiency of the pump light to laser light from the first pump module. The control module sets the portion of the output laser power less than 50% to be contributed by the second pump module, and the portion of the output laser power greater than 50% to be contributed by the first pump module. For the first pump module: TΔ A =|TAG-TA| (7) Where TAG=50~55℃ is the temperature when the half-width range of the emitted spectrum of the pump source chip inside the first pump module falls to 974-977nm, and TA is the temperature data collected in real time for the first pump module. When the ambient temperature is between 10℃ and 30℃, the first pump module and the second pump module have the same contribution weight to the total pump power of the laser, each accounting for half. Pout≈2×(P B ×PCE B )≈2×(P A ×PCE A )(7) When the ambient temperature is between 30℃ and 45℃, the contribution weight of the first pump module to the total pump power of the laser is increased, and the contribution weight of the second pump module to the total pump power of the laser is decreased. Specifically, the contribution weight of the first pump module to the total pump power of the laser is 60%, and the contribution weight of the second pump module to the total pump power of the laser is 40%.

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