Efficient gas laser pumping system based on energy-saving jet plasma

Abstract

The invention discloses a high-efficiency gas laser pumping system based on energy-saving jet plasma. The high-efficiency gas laser pumping system comprises an optical resonant cavity unit, a dual excitation unit, an energy supply unit, a circulating voltage stabilization unit and a laser detection unit, the optical resonant cavity unit comprises a closed cavity and a laser resonant cavity supported in the closed cavity; the dual excitation unit comprises a plasma jet device and a semiconductor laser device; the plasma jet device is used for forming a jet region in the middle of the laser resonant cavity; the energy supply unit is used for providing a working medium for the plasma jet device and providing an electric field condition meeting plasma discharge; the circulating pressure stabilizing unit is communicated with the closed cavity, so that the environment in the closed cavity is always in a pressure stabilizing state; and the laser detection unit is arranged outside the optical resonant cavity unit. The invention relates to the technical field of plasma laser pumping, and through the arrangement, the functions of energy conservation, high efficiency, self-cooling and service life prolonging are achieved.

Description

Technical Field

[0001] The invention belongs to the field of lasers and relates to a plasma laser pumping technology, in particular to a high-efficiency gas laser pumping system based on energy-saving jet plasma. Background Art

[0002] An inert gas laser device is a laser pumping device that uses an inert gas as a working medium. By exciting gas atoms to a high energy level, characteristic spectral lines can be generated when the atoms transition from a high energy level to a low energy level. The inert gas laser pumping device is chemically stable and harmless, and can also avoid the thermal effects generated by the solid working medium. It is expected to become a potential new type of high-power laser pumping device with high total conversion efficiency and high beam quality. However, traditional inert gas laser pumping devices have problems such as low efficiency, high energy consumption, and difficult thermal management. When working at high power, its energy conversion efficiency is not high, and the large amount of heat generated is difficult to effectively dissipate, resulting in a shortened device life. At the same time, due to the inherent structural limitations of the laser and the self-absorption effect of gas atoms, the gas laser outputs insufficient photons, and the gas discharge sputters to the transparent window, resulting in a decrease in the transmittance of the window.

[0003] Therefore, an efficient gas laser pumping system based on energy-saving jet plasma is needed to solve the above problems. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes an efficient gas laser pumping system based on energy-saving jet plasma to achieve energy saving, high efficiency, self-cooling and extended service life. The present invention provides an optical resonant cavity unit including a closed cavity and a laser resonant cavity, a dual excitation unit including a plasma jet device and a semiconductor laser device, and a circulating voltage stabilizing unit for evacuating the closed cavity according to the amount of gas ejected by the plasma jet device. The dual excitation unit is used to perform dual excitation on the working medium, which significantly improves the energy conversion efficiency and beam quality, and enables the laser system to stably output high-density plasma under a low starting voltage, thereby improving the overall performance of the system; and, by using the circulating voltage stabilizing unit, the gas pressure in the closed cavity can be stably controlled to ensure that the system operates under ideal working conditions. Therefore, compared with traditional gas lasers, this design effectively reduces the sensitivity of the laser system to gas pressure fluctuations, provides more reliable laser output, and in the process, the heat generated by the laser system running in the closed cavity can be discharged through the circulating voltage stabilizing unit, that is, the circulating voltage stabilizing unit also plays a role in gas circulation, so as to effectively dissipate a large amount of heat and achieve the purpose of effectively extending the service life of the laser system.

[0005] To achieve the above-mentioned object, the first aspect of the present invention provides a high-efficiency gas laser pumping system based on energy-saving jet plasma, comprising an optical resonant cavity unit, a dual excitation unit, an energy supply unit, a cyclic voltage stabilization unit and a laser detection unit;

[0006] The optical resonant cavity unit comprises a sealed cavity and a laser resonant cavity supported in the sealed cavity;

[0007] The dual excitation unit comprises a plasma jet device and a semiconductor laser device which are sealed and connected to the closed cavity, wherein the plasma jet device is used to form a jet region in the middle of the laser resonant cavity, and the semiconductor laser device is used to pump the laser gain medium in the jet region;

[0008] The energy supply unit is used to provide working medium to the plasma jet device and to provide electric field conditions that meet plasma discharge;

[0009] The circulating pressure stabilizing unit is in communication with the closed chamber, and is used to evacuate the closed chamber according to the amount of gas ejected by the plasma jet device, so that the environment in the closed chamber is always in a stable pressure state;

[0010] The laser detection unit is arranged outside the optical resonant cavity unit, and is used to measure the output power of the laser output by the laser resonant cavity.

[0011] Furthermore, the laser resonant cavity comprises a cavity body fixedly connected to the closed cavity via a connector on one side, a Brewster window, a total reflection concave lens and a total reflection convex lens;

[0012] The cavity is in communication with the closed cavity;

[0013] The Brewster window is arranged inside the cavity and located at a side away from the connecting member;

[0014] The total reflection concave lens and the total reflection convex lens are placed on both sides of the inner cavity of the cavity;

[0015] Wherein, the total reflection convex lens is placed in the middle of the Brewster window.

[0016] Furthermore, the area of ​​the side of the total reflection convex lens facing the Brewster window is between one fifth and one third of the light transmission area of ​​the Brewster window.

[0017] Furthermore, the Brewster window is made of fused quartz, and the Brewster angle of the Brewster window is set to 40°-50°.

[0018] Furthermore, a side of the sealed cavity close to the Brewster window is provided as a protective lens;

[0019] The laser detection unit is used to detect the laser that passes through the Brewster window and the protective lens in sequence.

[0020] Furthermore, the working medium of the plasma jet device is argon, helium and a mixture of the above gases;

[0021] The working gas pressure of the plasma jet device is 1 atm;

[0022] The jet velocity of the plasma jet device is 1Lmin –1 ;

[0023] The pulse voltage peak value and pulse frequency of the plasma jet device are 1.8 kV and 10 kHz respectively;

[0024] The central wavelength of the semiconductor laser device is set to 811.5nm, and the pump light intensity of the semiconductor laser device is 20kWcm –2 .

[0025] Furthermore, the working medium is a mixture of argon and helium;

[0026] Among them, argon accounts for 1%-3%, and helium accounts for 97%-99%.

[0027] Furthermore, the energy supply unit includes a gas supply system and a power supply system driven by green electricity;

[0028] The gas supply system and the power supply system are both connected to the plasma jet device, and are used to provide working medium and provide electric field conditions that meet plasma discharge, respectively.

[0029] Furthermore, the circulation pressure stabilizing unit is configured as a vacuum pump.

[0030] Further, the laser detection unit includes an attenuation sheet and a laser power meter which are arranged in sequence;

[0031] Wherein, the attenuation multiple of the attenuation sheet is 90 times to 110 times.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] By providing an optical resonant cavity unit including a closed cavity and a laser resonant cavity, a dual excitation unit including a plasma jet device and a semiconductor laser device, and a circulating voltage stabilizing unit for evacuating the closed cavity according to the amount of gas ejected by the plasma jet device, the working medium is doubly excited with the help of the dual excitation unit, which significantly improves the energy conversion efficiency and beam quality, and enables the laser system to stably output high-density plasma at a relatively low starting voltage, thereby improving the overall performance of the system.

[0034] In addition, by using a circulating voltage stabilization unit, the gas pressure in the closed cavity can be stably controlled to ensure that the system operates under ideal working conditions. Therefore, compared with traditional gas lasers, this design effectively reduces the sensitivity of the laser system to gas pressure fluctuations and provides more reliable laser output.

[0035] In addition, during the extraction process, the circulating voltage stabilizing unit can discharge the heat generated by the laser system running in a closed cavity through the circulating voltage stabilizing unit, that is, the circulating voltage stabilizing unit also plays the role of gas circulation, so it can effectively dissipate a large amount of heat to reduce the risk of overheating of the system during operation, thereby effectively extending the service life of the laser system.

[0036] Furthermore, by setting up an energy supply unit including a gas supply system and a power supply system driven by green electricity, when the plasma jet device is in operation, it can promote the on-site consumption of renewable energy, save electricity consumption, and contribute to the carbon neutrality goal. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 It is a structural schematic diagram of a high-efficiency gas laser pumping system based on energy-saving jet plasma in one embodiment of the present invention;

[0039] Figure 2 The figure is a schematic diagram of the structure of the laser resonant cavity in a high-efficiency gas laser pumping system based on energy-saving jet plasma in one embodiment of the present invention.

[0040] Figure Number:

[0041] 1. Sealed cavity; 11. Protective lens; 2. Laser resonant cavity; 21. Cavity; 22. Brewster window; 23. Total reflection concave lens; 24. Total reflection convex lens; 3. Plasma jet device; 4. Semiconductor laser device; 5. Jet area; 6. Gas supply system; 7. Power supply system; 8. Vacuum pump; 9. Attenuation plate; 10. Laser power meter. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 and Figure 2 The first embodiment of the present invention provides a high-efficiency gas laser pumping system based on energy-saving jet plasma, including an optical resonant cavity unit, a dual excitation unit, an energy supply unit, a cyclic voltage stabilization unit and a laser detection unit.

[0044] The optical resonant cavity unit includes a sealed cavity 1 and a laser resonant cavity 2 supported in the sealed cavity 1 .

[0045] The dual excitation unit includes a plasma jet device 3 and a semiconductor laser device 4 which are sealed and connected to the closed cavity 1. The plasma jet device 3 is used to form a jet region 5 in the middle of the laser resonant cavity 2, and the semiconductor laser device 4 is used to pump the laser gain medium in the jet region 5. The dual excitation of the working medium by the plasma jet device 3 and the semiconductor laser device 4 significantly improves the energy conversion efficiency and beam quality, and enables the laser system to stably output high-density plasma at a lower starting voltage, thereby improving the overall performance of the system.

[0046] The energy supply unit is used to provide working medium to the plasma jet device 3 and to provide electric field conditions that meet the plasma discharge.

[0047] In one example, the energy supply unit includes a gas supply system 6 and a power supply system 7 driven by green electricity.

[0048] The gas supply system 6 and the power supply system 7 are both connected to the plasma jet device 3, and are used to provide working medium and electric field conditions that meet plasma discharge, respectively. Since the gas supply system 6 and the power supply system 7 are both driven by green electricity, when the plasma jet device 3 is in operation, it can promote the local consumption of renewable energy, save electricity consumption, and help achieve the carbon neutrality goal.

[0049] In addition, the circulating voltage stabilizing unit is connected to the closed chamber 1, and is used to evacuate the closed chamber 1 according to the amount of gas ejected by the plasma jet device 3, so that the environment in the closed chamber 1 is always in a stable voltage state. It should be noted that the output end of the plasma jet device 3 and the semiconductor laser device 4 are both arranged in the closed chamber 1, so by making the closed chamber 1 always in a stable voltage state, it can ensure that the laser system operates under ideal working conditions. Compared with traditional gas lasers, it effectively avoids the technical defect that the plasma jet device 3 and the semiconductor laser device 4 are affected by gas pressure fluctuations, resulting in unstable laser output in the subsequent process, so that the laser system can output more stable laser.

[0050] It should also be noted that, since the circulating voltage stabilizing unit can discharge the heat generated by the operation of the laser system in the closed chamber 1 (such as the heat generated by the operation of the semiconductor laser device 4 and the plasma jet device 3) through the circulating voltage stabilizing unit during the extraction process, that is, the circulating voltage stabilizing unit also plays a role in gas circulation, it can effectively dissipate a large amount of heat to reduce the risk of overheating of the system during operation, thereby effectively extending the service life of the laser system.

[0051] The laser detection unit is arranged outside the optical resonant cavity unit, and is used to measure the output power of the laser output by the laser resonant cavity 2, so that the operation of the system can be optimized and debugged according to the output power as a feedback parameter.

[0052] like Figure 2 As shown, in this embodiment, the specific structure of the laser resonant cavity 2 is further described so that the laser can be better output to the laser detection unit.

[0053] Specifically, the laser resonant cavity 2 includes a cavity body 21 , one side of which is fixedly connected to the sealed cavity 1 via a connector, a Brewster window 22 , a total reflection concave lens 23 , and a total reflection convex lens 24 .

[0054] The cavity 21 is in communication with the closed cavity 1 , and the closed cavity 1 is evacuated by the circulating pressure stabilizing unit to realize the function of gas circulation and achieve the purpose of cooling and heat dissipation.

[0055] The Brewster window 22 is disposed inside the cavity 21 and is located at a side away from the connecting member.

[0056] Furthermore, the total reflection concave lens 23 and the total reflection convex lens 24 are disposed on two sides of the inner cavity of the cavity 21 .

[0057] It should be noted that, in this embodiment, the connecting member can be configured as a plurality of fixed connecting strips arranged in a ring shape, that is, it only plays the role of supporting the cavity 21. Its specific structure can also be set to other shapes. It only needs to support the cavity 21 and ensure that the cavity 21 is in a connected state with the closed cavity 1, so it will not be elaborated here.

[0058] It should also be noted that the total reflection convex lens 24 is placed in the middle of the Brewster window 22 to ensure that the light beam is concentrated in the central area of ​​the Brewster window 22, reduce the risk of uneven heating of the Brewster window 22, improve the long-term stability of the system, and avoid optical distortion caused by thermal expansion.

[0059] In a further embodiment, the area of ​​the total reflection convex lens 24 facing the Brewster window 22 is between one fifth and one third of the light transmission area of ​​the Brewster window 22. Preferably, the area of ​​the total reflection convex lens 24 facing the Brewster window 22 is one quarter of the light transmission area of ​​the Brewster window 22.

[0060] In other embodiments, the Brewster window 22 is made of fused silica, and the Brewster angle of the Brewster window 22 is set to 40°-50°. By limiting the Brewster angle, the refractive index of the fused silica material can be matched, the reflection loss can be reduced, and the light transmission efficiency can be significantly improved. Preferably, the Brewster angle of the Brewster window 22 is set to 45°.

[0061] In a further embodiment, a protective lens 11 is provided on one side of the sealed cavity 1 close to the Brewster window 22, and the laser detection unit is used to detect the laser that sequentially passes through the Brewster window 22 and the protective lens 11. That is, the protective lens 11 is provided to prevent dust, debris or other contaminants in the external environment from directly entering the optical path system of the laser, and to avoid damaging the laser detection unit, thereby protecting the laser detection unit.

[0062] In this embodiment, the working medium of the plasma jet device 3 is argon, helium and a mixture of the above gases, the working gas pressure of the plasma jet device 3 is 1 atm, and the jet speed of the plasma jet device 3 is 1 Lmin –1， The pulse voltage peak value and pulse frequency of the plasma jet device 3 are 1.8 kV and 10 kHz respectively, the central wavelength of the semiconductor laser device 4 is set to 811.5 nm, and the pump light intensity of the semiconductor laser device 4 is 20 kW cm –2 .

[0063] In one example, the working medium is a mixture of argon and helium, wherein the proportion of argon is 1%-3%, and the proportion of helium is 97%-99%.

[0064] In this embodiment, the circulating voltage stabilizing unit is configured as a vacuum pump 8, which is connected to the closed chamber 1 via an interface to evacuate gas according to the amount of gas output by the plasma jet device 3, so that the closed chamber 1 is always in a voltage stabilizing state, thereby ensuring the stability of the overall laser system operation.

[0065] In a further embodiment, the laser detection unit includes an attenuation sheet 9 and a laser power meter 10 which are arranged in sequence. It should be noted that the attenuation multiple of the attenuation sheet 9 is 90 times to 110 times. In this embodiment, the attenuation sheet 9 is used to reduce the intensity of the light beam to prevent the measuring device from being overloaded, and the laser power meter 10 is used to accurately measure the power of the output laser to ensure the accuracy of the measurement.

[0066] In one of the examples, the performance of the above-mentioned high-efficiency gas laser pumping system based on energy-saving jet plasma was further explored through experiments, as shown in Table 1:

[0067]

[0068]

[0069] Table 1

[0070] From the data in Table 1, it can be seen that under the conditions that the pump light power and discharge power of the high-efficiency gas laser pumping system based on energy-saving jet plasma are 3.8kW and 0.78kW respectively, a laser output of 1.9kW is achieved, at which time the discharge power accounts for 21% of the pump light power, the optical conversion efficiency is 50%, and the total conversion efficiency is 41%. Compared with traditional gas lasers with a total conversion efficiency of 10%-30%, the high-efficiency gas laser pumping system based on energy-saving jet plasma has the characteristics of low discharge power, high optical conversion efficiency, and energy saving and cleanliness.

[0071] In another example, under the same pump light power of 4.58 kW, we measured the operating temperatures of a high-efficiency gas laser pumping system based on energy-saving jet plasma, a conventional gas laser device, and a conventional solid-state laser device, as shown in Table 2:

[0072]

[0073] It can be seen from the data in Table 2 that, since the high-efficiency gas laser pumping system based on energy-saving jet plasma adopts a circulating voltage stabilizing unit to circulate the gas in the closed cavity 1, its heat dissipation performance is significantly better than that of the other two traditional laser pumping devices, that is, it achieves the purpose of good heat dissipation performance, thereby effectively extending the service life of the device.

[0074] In summary, the high-efficiency gas laser pumping system based on energy-saving jet plasma proposed in the present invention has the following characteristics:

[0075] (1) Use green electricity to drive plasma jets to promote local consumption of renewable energy, save electricity consumption, and help achieve carbon neutrality goals;

[0076] (2) The two-stage excitation method of the coordinated plasma jet device 3 and the semiconductor laser device 4 significantly improves the energy conversion efficiency and beam quality compared with the traditional gas laser. This dual excitation mechanism not only optimizes the excitation process, but also enables the laser to stably output high-density plasma at a lower starting voltage, thereby improving the overall performance of the system;

[0077] (3) The circulating voltage stabilization unit realizes stable control of gas pressure by simultaneously regulating the operation of the plasma jet device 3 and the vacuum pump 8, ensuring that the system operates under ideal working conditions. Compared with traditional gas lasers, this design effectively reduces the sensitivity of the laser to gas pressure fluctuations and provides more reliable laser output;

[0078] (4) Through the operation of the vacuum pump 8, the heat in the closed chamber 1 can be effectively extracted, thereby effectively reducing the risk of overheating of the system during operation and extending the service life of the laser. Compared with traditional gas lasers, this superior heat dissipation performance ensures that the laser can operate stably in higher power applications, showing excellent thermal management capabilities.

[0079] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A high-efficiency gas laser pumping system based on energy-saving jet plasma, characterized in that: It includes an optical resonant cavity unit, a dual excitation unit, an energy supply unit, a circulating voltage stabilization unit and a laser detection unit; The optical resonant cavity unit comprises a sealed cavity (1) and a laser resonant cavity (2) supported in the sealed cavity (1); The dual excitation unit comprises a plasma jet device (3) and a semiconductor laser device (4) which are sealed and connected to the closed cavity (1); the plasma jet device (3) is used to form a jet region (5) in the middle of the laser resonant cavity (2); and the semiconductor laser device (4) is used to pump the laser gain medium in the jet region (5); The energy supply unit is used to provide a working medium to the plasma jet device (3) and to provide an electric field condition satisfying plasma discharge; The circulating pressure stabilizing unit is in communication with the closed chamber (1) and is used to evacuate the closed chamber (1) according to the amount of gas ejected by the plasma jet device (3), so that the environment inside the closed chamber (1) is always in a stable pressure state; The laser detection unit is arranged outside the optical resonant cavity unit and is used to measure the output power of the laser output by the laser resonant cavity (2).

2. According to claim 1, a high-efficiency gas laser pumping system based on energy-saving jet plasma is characterized in that: The laser resonant cavity (2) comprises a cavity body (21) fixedly connected to the sealed cavity (1) on one side via a connecting piece, a Brewster window (22), a total reflection concave lens (23) and a total reflection convex lens (24); The cavity (21) is in communication with the sealed cavity (1); The Brewster window (22) is arranged inside the cavity (21) and is located on a side away from the connecting member; The total reflection concave lens (23) and the total reflection convex lens (24) are placed on both sides of the inner cavity of the cavity (21); Wherein, the total reflection convex lens (24) is placed in the middle of the Brewster window (22).

3. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 2, characterized in that: The area of ​​the total reflection convex lens (24) facing the Brewster window (22) is between one fifth and one third of the light transmission area of ​​the Brewster window (22).

4. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 2, characterized in that: The Brewster window (22) is made of fused quartz, and the Brewster angle of the Brewster window (22) is set to 40°-50°.

5. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 2, characterized in that: A protective lens (11) is arranged on one side of the sealed cavity (1) close to the Brewster window (22); The laser detection unit is used to detect the laser that passes through the Brewster window (22) and the protective lens (11) in sequence.

6. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 1, characterized in that: The working medium of the plasma jet device (3) is argon, helium and a mixture of the above gases; The working gas pressure of the plasma jet device (3) is 1 atm; The jet velocity of the plasma jet device (3) is 1 Lmin –1 ; The peak value of the pulse voltage and the pulse frequency of the plasma jet device (3) are 1.8 kV and 10 kHz respectively; The central wavelength of the semiconductor laser device (4) is set to 811.5 nm, and the pump light intensity of the semiconductor laser device (4) is 20 kW cm –2 .

7. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 6, characterized in that: The working medium is a mixture of argon and helium; Among them, argon accounts for 1%-3%, and helium accounts for 97%-99%.

8. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 1, characterized in that: The energy supply unit includes a gas supply system (6) and a power supply system (7) driven by green electricity; The gas supply system (6) and the power supply system (7) are both connected to the plasma jet device (3), and are used to provide a working medium and provide an electric field condition satisfying plasma discharge, respectively.

9. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 1, characterized in that: The circulating pressure stabilizing unit is configured as a vacuum pump (8).

10. The high-efficiency gas laser pumping system based on energy-saving jet plasma according to claim 1, characterized in that: The laser detection unit comprises an attenuation sheet (9) and a laser power meter (10) which are arranged in sequence; Wherein, the attenuation factor of the attenuation sheet (9) is 90 times to 110 times.

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