Self-adaptive wide-temperature-interval air-cooled fiber laser and control method

Abstract

The invention relates to a self-adaptive wide-temperature-interval air-cooled fiber laser and a control method, the self-adaptive wide-temperature-interval air-cooled fiber laser comprises a shell, a first pumping module, a second pumping module, a control module, a first current driving module and a second current driving module are arranged in the shell, the first current driving module is connected with the first pumping module, and the second current driving module is connected with the second pumping module. The first current driving module is connected with the first pumping module, the second current driving module is connected with the second pumping module, a laser gain cavity is formed in the side face of the shell, a first fan and a second fan are arranged on one side of the shell, a first air cooling heat dissipation plate and a second air cooling heat dissipation plate are arranged on the other side of the shell, and the laser gain cavity is connected with the first pumping module and the second pumping module. The first fan, the second fan, the first pumping module, the second pumping module, the first current driving module and the second current driving module are all connected with the control module, and the laser gain cavity is connected with an optical fiber cladding light filter. By controlling the temperature environment, the pump light conversion rate is increased.

Description

Technical Field

[0001] The invention relates to a fiber laser, in particular to an air-cooled fiber laser with a self-adaptive wide temperature range and a control method. Background Art

[0002] Fiber lasers have developed rapidly in recent years due to their many advantages. In recent years, direct air-cooled (or forced air-cooled) fiber lasers with small size and lighter weight have been widely used in the field of miniaturized fiber laser applications. Because laser systems based on direct air-cooled fiber lasers, such as welding and cutting, do not require the support of compressors or other refrigeration systems during use. However, the current direct-cooled fiber laser uses a pump source in the 915nm optical band, and the conversion efficiency of pump light to laser is generally only 60-70%. Even if a high-efficiency pump source module with an electro-optical conversion efficiency of 50%-55% is used, the conversion efficiency of electrical energy to laser energy is only 25-35%. According to the principle of conservation of energy, it is obvious that under the same laser output power, this type of laser generates more heat, puts more pressure on the heat dissipation system, and has greater noise; similarly, under the same heat dissipation conditions, this type of laser is more likely to attenuate.

[0003] Although in recent years, fiber laser systems have already used pump sources in the 976nm optical band to achieve a pump light conversion efficiency of more than 80%. However, since the active fiber of the laser has a narrow spectral absorption range for the 976nm optical band, and the output wavelength fluctuates widely with temperature and current when the pump source is working, it is difficult for the laser output efficiency to take into account various temperature ranges. This means that direct air-cooled fiber lasers without non-refrigeration systems are difficult to use conventional 976nm optical band pump sources. In general, the pump light conversion rate of current lasers is relatively low and difficult to be fully utilized. Summary of the invention

[0004] In order to solve the above technical problems, the present invention contributes an air-cooled fiber laser with an adaptive wide temperature range.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] An air-cooled fiber laser with an adaptive wide temperature range comprises a shell, wherein a first pumping module, a second pumping module, a control module, a first current driving module and a second current driving module are arranged in the shell, the first current driving module is connected to the first pumping module, the second current driving module is connected to the second pumping module, a laser gain cavity is arranged on the side of the shell, a first fan and a second fan are arranged on one side of the shell, a first air-cooled heat sink and a second air-cooled heat sink are arranged on the other side of the shell, the first fan, the first pumping module and the first air-cooled heat sink are distributed in the same straight line direction, the second fan, the second pumping module and the second air-cooled heat sink are distributed in the same straight line direction, the laser gain cavity is connected to the first pumping module and the second pumping module respectively, the first fan, the second fan, the first pumping module, the second pumping module, the first current driving module and the second current driving module are all connected to the control module, and the laser gain cavity is connected to a fiber cladding optical filter.

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

[0008] The wavelengths of the first pump module and the second pump module are different, 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 an ytterbium-doped optical fiber with a length greater than or equal to 33 meters as an active optical fiber.

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

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

[0012] Real-time detection of the ambient temperature around the laser and the real-time temperatures of the first pump module and the second pump module; control of the first pump module and the second pump module to operate independently or together to output laser power according to the ambient temperature; comparison of the detected real-time temperature with the set temperature to control the drive current, adjust the output power of the first pump module and the second pump module, and control the air supply of the first fan and the second fan.

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

[0014] The control module only controls the current value output by the second current driving module to contribute driving current to the second pumping module;

[0015] Real-time detection of the temperature of the second pump module, which represents the temperature of the pump chip inside the second pump module, obtains the real-time temperature change value TΔ of the internal pump chip, and obtains the wavelength drift LΔ of the pump chip inside the second pump module by the following formula;

[0016] LΔ≈0.31×TΔ, (2)

[0017] 0.31 is the drift coefficient;

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

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

[0020] PCE corresponding to the wavelength shift LΔ B The PCE corresponding to different TΔ was experimentally calculated with a step of 1°C. B , for the second pump module:

[0021] TΔ B =|TBG-TB| (4)

[0022] Wherein, TBG=45-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the second pump module falls to 974-977nm after superposition, 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 value 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 turn-on current;

[0027] The control module dynamically adjusts the current value corresponding to the second pump module according to the temperature data TB collected from the second pump module;

[0028] 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-wave 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 lower than 10°C and the output laser power of the laser is set to be higher than 50% of the rated power, the first pump module and the second pump module will be started at the same time, and the laser will be pumped by the first pump module and the second pump module at the same time. At this time:

[0030] Pout≈PB×PCE B +PA×PCE A (6)

[0031] PCE A is the conversion efficiency of the pump light of the first pump module into laser light. The control module sets the output laser power less than 50% to be contributed by the second pump module 3B, and sets 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] Wherein, TAG=55-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the first pump module falls to 974-977nm after superposition, and TA is the temperature data collected in real time from the first pump module;

[0034] When the ambient temperature is 10℃-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°C-45°C, 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 reduced; 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, and the cladding light at the front end and the rear end of the fiber cladding tube filter is detected and collected. The difference between the cladding light at the front end and the rear end of the fiber cladding tube filter is set to PDΔ, and the difference PDΔ is positively correlated with the proportion of the cladding light not absorbed in the laser gain cavity, and the standard deviation PDΔG is set;

[0038] If the difference between the detected PDΔ and PDΔG is greater than 1 / 2 of the PDΔG value, the first fan and the second fan are controlled to reduce their speeds until the difference between PDΔ and PDΔG is less than 1 / 2 of the PDΔG value, and then the first fan and the second fan resume their original speeds.

[0039] The air supply volume is adjusted by controlling the rotation speeds of the first fan and the second fan through the difference 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 air supply of the fan, the temperature is maintained within an optimal range, and the pump light conversion rate is increased to 82-86, which will not cause an overheating environment, is not easy to be damaged, and prolongs the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the cutaway structure of the present invention;

[0043] Figure 2 It is a schematic diagram of the connection principle of the present invention. DETAILED DESCRIPTION

[0044] The 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 throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0045] In the description of the present invention, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are involved, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] like Figure 1 and 2As shown, an air-cooled fiber laser with an adaptive wide temperature range includes a shell, in which a first pump module 31, a second pump module 32, a control module 1, a first current driving module 21 and a second current driving module 22 are arranged, the first current driving module 21 is connected to the first pump module 31, and the second current driving module 22 is connected to the second pump module 32, a laser gain cavity is arranged on the side of the shell, a first fan 51 and a second fan 52 are arranged on one side of the shell, and a first air-cooled heat sink 41 and a second air-cooled heat sink 42 are arranged on the other side of the shell, the first fan, the first pump module and the first air-cooled heat sink are distributed in the same straight line direction, the second fan, the second pump module and the second air-cooled heat sink are distributed 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 driving module and the second current driving module are all connected to the control module, and the laser gain cavity is connected to a fiber cladding light filter. The first fan mainly provides cooling and heat dissipation for the first pump module and the first current drive module, and the second fan mainly provides cooling and heat dissipation for the second pump module and the second current drive module. The control module is used to control the speed of the first fan and the second fan, that is, to control the air supply. The higher the speed, the greater the air supply, and the lower the speed, the smaller the air supply. In this way, the fiber laser can dynamically meet the power set by the user and achieve self-adaptation in a wider ambient temperature range, ensuring a higher electro-optical conversion efficiency.

[0048] The first pump module 31 and the second pump module 32 are both connected to a pump temperature sensor, the first air-cooled heat sink and the second air-cooled heat sink are both connected to a heat sink temperature sensor, the optical fiber cladding light filter is connected to a photosensor, the pump temperature sensor, the heat sink temperature sensor and the photosensor are all connected to the control module, and the control module is also connected to an ambient temperature sensor. The temperature can be collected in real time through each temperature sensor. The temperature collected by the pump temperature sensor can be approximately characterized as the temperature of the internal pump chip. The ambient temperature sensor 9 is installed at the air inlet of the laser, which can collect the ambient temperature more accurately.

[0049] Generally speaking, in order to consider stability and service life, the direct air-cooled fiber laser will leave about 10%-15% pump power margin. For fiber lasers with the same rated output power Pout and the same total pump light 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 value Pi of the pump module and the rated optical power Pout of the laser are related as follows:

[0051] Pout≈Pi×(1-δ)×PCE(1)

[0052] The manufacturing cost of the laser is positively correlated to the total pump light power to a large extent. The higher the total pump light power, the higher the manufacturing cost. As can be seen from the above relationship, although the present application increases the pump power redundancy δ, it does not significantly increase the total pump light power. Therefore, the manufacturing cost of the above laser provided by the present application will not increase significantly; this means that the solution provided by the present application can improve reliability without significantly increasing the manufacturing cost because the pump power redundancy is greatly increased.

[0053] The laser gain cavity uses a conventional ytterbium-doped fiber YDF with a length of at least 33m as the active fiber. Generally, the absorption characteristics of the YDF fiber determine that the laser gain cavity has the best absorption rate for the laser emitted by the pump source with a wavelength between 974 and 977nm, which can make the conversion efficiency PCE of the pump light to the laser reach the target efficiency value; the application uses a sufficient YDF length, which can reduce the influence of the wavelength drift LΔ of the pump light on the PCE to a certain extent.

[0054] The pump source chips inside the first pump source module and the second pump source module used in the present application meet the following characteristics: the wavelength of the pump source chip is generally linearly positively correlated with the operating temperature, with a drift of 0.31nm / °C. For every 1°C increase in temperature, the wavelength increases by 0.31nm; for every 1°C decrease in temperature, the wavelength decreases by 0.31nm.

[0055] The wavelengths of the first pump module and the second pump module are different, 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, the present invention discloses a control method for an air-cooled fiber laser with an adaptive wide temperature range, comprising the following steps:

[0057] Real-time detection of the ambient temperature around the laser and the real-time temperatures of the first pump module and the second pump module; control of the first pump module and the second pump module to operate independently or together to output laser power according to the ambient temperature; comparison of the detected real-time temperature with the set temperature to control the drive current, adjust the output power of the first pump module and the second pump module, and control the air supply of the first fan and the second fan.

[0058] For direct air-cooled fiber lasers that rely directly on fan forced air cooling, the operating temperature of the pump chips of the first pump module and the second pump module is related to the ambient temperature, the heat dissipation capacity of the heat dissipation system, and the operating current of the pump chip; the ambient temperature determines the base temperature, and the heat dissipation capacity of the heat dissipation system and the operating current of the pump source chip determine the temperature rise; the operating temperature of the pump source chip is approximately equal to the sum of the base temperature and the temperature rise; there are a large number of pump source chips inside the pump source, and the chips are in series circuits, and the current is equal everywhere, so the heat generation of all pump chips is approximately the same. When the heat dissipation conditions are the same, the temperature rise of the pump chips at most positions inside the pump source is the same. Therefore, a single temperature sampling point can be set on the first pump module and the second pump module to approximately characterize the temperature of the pump source chip; the real-time temperature collected by the pump module temperature sensor is linearly related to the temperature of the pump source chip.

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

[0060] The temperature TAG=55-60°C when the half-wave width range of the output spectra of the pump source chips inside the first pump module falls to 974-977nm after superposition; the temperature TBG=45-50°C when the half-wave width range of the output spectra of the pump source chips inside the second pump module falls to 974-977nm after superposition; 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 two pump module temperature sensors can be used to approximately reflect the wavelength drift LΔ of the pump source chip;

[0062] LΔ≈0.31×TΔ; (2)

[0063] As a direct air-cooled fiber laser that directly relies on fan forced air cooling, the ambient temperature determines the base temperature of the first pump module and the second pump module, and the heat dissipation capacity of the heat dissipation system composed of two air-cooled heat sinks and two fans and the operating current of the pump source chip inside the first pump source module and the second pump module determine the temperature rise; based on the above characteristics, the direct air-cooled fiber laser described in this application can easily make the operating temperature of the first pump module and the second pump module exceed the ambient temperature, but cannot make the operating temperature of the two pump modules lower than the ambient temperature. Therefore, this application gives priority to a temperature environment of 45°C for the selection of the pump source module and the heat dissipation capacity of the heat dissipation system.

[0064] There is a difference in wavelength between the first pump module and the second pump module, 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 if it operates at the maximum rated power.

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

[0066] The control module only controls the current value output by the second current driving module to contribute driving current to the second pumping module.

[0067] Real-time detection of the temperature of the second pump module, which represents the temperature of the pump chip inside the second pump module, obtains the real-time temperature change value TΔ of the internal pump chip, and obtains the wavelength drift LΔ of the pump chip inside the second pump module by the following formula;

[0068] LΔ≈0.31×TΔ, (2)

[0069] 0.31 is the drift coefficient;

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

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

[0072] PCE corresponding to the wavelength shift LΔ B The PCE corresponding to different TΔ was experimentally calculated with a step of 1°C. B , for the second pump module:

[0073] TΔ B =|TBG-TB| (4)

[0074] Wherein, TBG=45-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the second pump module falls to 974-977nm after superposition, 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 value 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 turn-on current;

[0079] The control module dynamically adjusts the current value corresponding to the second pump module according to 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-wave width range of the superimposed emission 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 lower than 10°C and the output laser power of the laser is set to be higher than 50% of the rated power, the first pump module and the second pump module will be started at the same time, and the laser will be pumped by the first pump module and the second pump module at the same time. At this time:

[0082] Pout≈PB×PCE B +PA×PCE A (6)

[0083] PCE A is the conversion efficiency of the pump light of the first pump module into laser light. The control module sets the output laser power less than 50% to be contributed by the second pump module 3B, and sets 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] Wherein, TAG=55-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the first pump module falls to 974-977nm after superposition, and TA is the temperature data collected in real time from the first pump module;

[0086] When the ambient temperature is 10℃-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°C-45°C, 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 reduced; 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, and the cladding light at the front end and the rear end of the fiber cladding tube filter is detected and collected. The difference between the cladding light at the front end and the rear end of the fiber cladding tube filter is set to PDΔ, and the difference PDΔ is positively correlated with the proportion of the cladding light not absorbed in the laser gain cavity, and the standard deviation PDΔG is set;

[0090] If the difference between the detected PDΔ and PDΔG is greater than 1 / 2 of the PDΔG value, the first fan and the second fan are controlled to reduce their rotation speeds until the difference between PDΔ and PDΔG is less than 1 / 2 of the PDΔG value, at which time the first fan and the second fan resume their original rotation speeds. The air supply volume is adjusted by controlling the rotation speeds of the first fan and the second fan through the difference PDΔ.

[0091] For fiber lasers, the main function of the fiber cladding light filter CPS is to filter out the residual pump light at the laser output end that is not completely absorbed by the YDF fiber. Obviously, this can form a self-feedback mechanism: the lower the temperature, the greater the offset of the pump source output wavelength. Under the same power conditions, the more pump light is filtered out by the CPS, and the heat generated by the CPS will increase rapidly, which will quickly increase the temperature of the pump source module. The pump light will get closer and closer to the optimal absorption range of the YDF fiber, and then the heat generated by the CPS will continue to decrease;

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

[0093] It can be seen that by adjusting different operating parameters of the first pump module and the second pump module at different ambient temperatures, the laser is always kept in a condition of optimal pump light conversion efficiency.

[0094] It should be noted that the above are only 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, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air-cooled fiber laser with an adaptive wide temperature range, characterized in that: The invention comprises a shell, wherein a first pump module, a second pump module, a control module, a first current driving module and a second current driving module are arranged in the shell, the first current driving module is connected to the first pump module, the second current driving module is connected to the second pump module, a laser gain cavity is arranged on the side of the shell, a first fan and a second fan are arranged on one side of the shell, a first air-cooled heat sink and a second air-cooled heat sink are arranged on the other side of the shell, the first fan, the first pump module and the first air-cooled heat sink are distributed in the same straight line direction, the second fan, the second pump module and the second air-cooled heat sink are distributed 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 driving module and the second current driving module are all connected to the control module, and the laser gain cavity is connected to a fiber cladding optical filter.

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

3. The air-cooled fiber laser with an adaptive wide temperature range according to claim 1, characterized in that: The wavelengths of the first pump module and the second pump module are different, 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 an ytterbium-doped optical fiber with a length greater than or equal to 33 meters as an active optical fiber.

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

6. A control method for an adaptive wide temperature range air-cooled fiber laser according to any one of claims 2 to 5, characterized in that: The following steps are involved: Real-time detection of the ambient temperature around the laser and the real-time temperatures of the first pump module and the second pump module; control of the first pump module and the second pump module to operate independently or together to output laser power according to the ambient temperature; comparison of the detected real-time temperature with the set temperature to control the drive current, adjust the output power of the first pump module and the second pump module, and control the air supply of the first fan and the second fan.

7. The control method of the adaptive wide temperature range air-cooled fiber laser according to claim 6, characterized in that: When the ambient temperature is detected to be lower than 10°C and the output laser power of the set laser is lower than 50% of the rated power, the first pump module is turned off and the second pump module is operated; The control module only controls the current value output by the second current driving module to contribute driving current to the second pumping module; Real-time detection of the temperature of the second pump module, which represents the temperature of the pump chip inside the second pump module, obtains the real-time temperature change value TΔ of the internal pump chip, and obtains the wavelength drift LΔ of the pump chip inside the second pump module by the following formula; LΔ≈0.31×TΔ, (2) 0.31 is the drift coefficient; At this time, Pout≈P B ×PCE B (3) Where Pout is the set output laser power, P B is the output power of the second pump module, PCE B is the conversion efficiency of the pump light of the second pump module into laser light, PCE B It will change with the wavelength drift LΔ of the output pump light of the second pump module. According to formula (2), PCE B It changes with the collected temperature change value TΔ.

8. The control method of the adaptive wide temperature range air-cooled fiber laser according to claim 7, characterized in that: PCE corresponding to the wavelength shift LΔ B The PCE corresponding to different TΔ was experimentally calculated with a step of 1°C. B , for the second pump module: TΔ B =|TBG-TB| (4) Wherein, TBG=45-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the second pump module falls to 974-977nm after superposition, 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 output power Ppump of the second pump module and the input current value I have the following approximate linear relationship: Ppump≈I×(KJ)(5) K is the pump power value per unit current, and J is the turn-on current; The control module dynamically adjusts the current value corresponding to the second pump module according to the temperature data TB collected from the second pump module; 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-wave width range of the superimposed emission spectrum of the pump source chip inside the second pump module falls between 974-977nm.

9. The control method of the adaptive wide temperature range air-cooled fiber laser according to claim 8, characterized in that: When the ambient temperature is lower than 10°C and the output laser power of the laser is set to be higher than 50% of the rated power, the first pump module and the second pump module will be started at the same time, and the laser will be pumped by the first pump module and the second pump module at the same time. At this time: Pout≈PB×PCE B +PA×PCE A (6) PCE A is the conversion efficiency of the pump light of the first pump module into laser light. The control module sets the output laser power less than 50% to be contributed by the second pump module 3B, and sets the output laser power greater than 50% to be contributed by the first pump module. For the first pump module: TΔA=|TAG-TA| (7) Wherein, TAG=55-50°C is the temperature when the half-wave width range of the pump source chip output spectrum of the first pump module falls to 974-977nm after superposition, and TA is the temperature data collected in real time from the first pump module; When the ambient temperature is 10℃-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×(PB×PCE B )≈2×(PA×PCE A (7) When the ambient temperature is 30℃-45℃, increase the contribution weight of the first pump module to the total pump power of the laser, and reduce the contribution weight of the second pump module to the total pump power of the laser; 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%.

10. The control method of the adaptive wide temperature range air-cooled fiber laser according to claim 9, characterized in that: A fiber cladding tube filter is connected to the output end of the laser gain cavity, and the cladding light at the front end and the rear end of the fiber cladding tube filter is detected and collected. The difference between the cladding light at the front end and the rear end of the fiber cladding tube filter is set to PDΔ, and the difference PDΔ is positively correlated with the proportion of the cladding light not absorbed in the laser gain cavity, and 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 fan and the second fan are controlled to reduce their speeds until the difference between PDΔ and PDΔG is less than 1 / 2 of the PDΔG value, and then the first fan and the second fan resume their original speeds. The air supply volume is adjusted by controlling the rotation speeds of the first fan and the second fan through the difference PDΔ.

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