Flat-round integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser

Abstract

This invention pertains to gas lasers in the field of gas discharge and laser applications. Specifically, it is a flat-circle integrated dielectric barrier discharge semiconductor-pumped inert gas laser, comprising a vacuum chamber, an electrical excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-voltage monitoring system, and a pumping and beam-emitting system. After the vacuum chamber is sealed by the sealing system assembly, the air inside is evacuated by the vacuum pumping system. When the vacuum monitoring system detects that the gas pressure inside the vacuum chamber meets the low-pressure condition, the gas supply system injects a predetermined proportion of inert gas. The total pressure of the injected inert gas is detected by the high-voltage monitoring system. After the inert gas is injected, the vacuum chamber is controlled by the electrical excitation system to generate metastable particles, which are then excited by the pumping and beam-emitting system to produce population inversion, thereby achieving the desired wavelength laser output. This invention has a simple structure, is easy to operate, and avoids the complexity of independently designing the dielectric barrier discharge device and the vacuum chamber.

Description

Technical Field

[0001] This invention pertains to gas lasers in the field of gas discharge and laser applications, specifically a flat-round integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser. Background Technology

[0002] With the continuous development of laser technology, the demand for high-power lasers in social production and national defense is constantly increasing, driving the rapid development of various high-power lasers. In the field of all-solid-state lasers, using beam combining technology and master oscillator power amplifier technology, the laser intensity has now reached 100kW. IPG Photonics' continuous industrial fiber laser has exceeded 100kW in output power, possessing advantages such as high stability and high electro-optical conversion efficiency. The highest-power chemical oxygen-iodine laser has been successfully applied in the national defense field and has completed ground tests. This demonstrates that various lasers have achieved a series of significant research results in the field of high-power output.

[0003] Despite the rapid progress and remarkable achievements in scientific exploration and technological invention of various high-power lasers, the research and application of lasers towards higher output power still face many challenges due to their inherent physical limitations: high-power fiber lasers are constrained by physical factors such as end-face damage and nonlinear effects, limiting the continuous improvement of single-fiber output power; high-power carbon dioxide lasers suffer from drawbacks such as large size and low excitation efficiency; high-power all-solid-state lasers have significant thermal effects, limiting further increases in output power; and the application of high-power chemical oxygen-iodine lasers in social production and daily life is also limited by their large size and potential chemical pollution.

[0004] While continuously breaking through the output bottlenecks of existing high-power lasers, the concept of semiconductor-pumped inert gas lasers has been proposed to further explore potential future high-power laser sources. Several research teams both domestically and internationally have also conducted research on this type of laser. Semiconductor-pumped inert gas lasers use metastable inert gas particles as the working medium, which are chemically stable and harmless, avoiding the thermal effects of solid-state working media. Furthermore, population inversion is achieved through semiconductor excitation, significantly improving electro-optical conversion efficiency while maintaining beam quality compared to traditional gas lasers. Therefore, high-power semiconductor-pumped inert gas lasers can overcome the disadvantages of both traditional solid-state lasers and gas lasers while combining their advantages.

[0005] Semiconductor-pumped inert gas lasers, as a novel type of hybrid laser, primarily combine semiconductor pumping with hybrid gas discharge excitation as their excitation method. In this system, the working medium particles participating in the laser cycle are generated through low-power discharge excitation. In other words, the number of metastable particles in the pump and laser lower energy levels of the laser system is mainly determined by the electrical excitation method. Since the performance of semiconductor-pumped inert gas lasers is closely related to the number of metastable particles, optimizing the discharge excitation system is crucial to achieving high-power and high-efficiency systems and fully realizing all the advantages of this laser system. This optimization aims to achieve efficient discharge excitation, thereby obtaining a high-density working medium. To ensure the metastable particle number concentration in this laser system, semiconductor-pumped inert gas lasers typically operate under high-pressure environments such as atmospheric pressure. The electrical excitation methods for generating a high-density metastable particle number under high-pressure environments generally include high-voltage nanosecond pulse discharge and mid-frequency AC dielectric barrier discharge. Although high-voltage nanosecond pulse discharges can easily generate high-density metastable particles, it is difficult to generate continuous and stable high-density metastable particles under high pressure. However, mid-frequency AC dielectric barrier discharge can achieve the generation of quasi-continuous and stable high-density metastable particles in high-pressure discharges. In particular, for semiconductor-pumped inert gas lasers filled with high-pressure helium as a buffer gas, mid-frequency AC dielectric barrier discharge can easily generate glow discharge modes. Located in the positive column region of glow discharge, it not only has a strong reduced electric field, but also easily generates quasi-continuous and stable discharges.

[0006] Another way to achieve continuous and stable discharge under high pressure is through DC corona discharge, which also produces a relatively high number of metastable particles. Therefore, how to fully realize continuous and stable discharge under high pressure and achieve a higher number of metastable particles remains a problem to be solved. Summary of the Invention

[0007] To meet the application requirements of novel high-power lasers, the present invention aims to provide a flat-circle integrated dielectric barrier discharge semiconductor-pumped inert gas laser that combines the advantages of solid-state lasers and gas lasers. This laser utilizes electrically excited inert gas to generate metastable particles, which are then pumped by a semiconductor laser to produce a new wavelength output.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] This invention discloses a flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser, comprising a vacuum cavity, an electrical excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-voltage monitoring system, and a pumping and light output system. The vacuum cavity is a hollow structure with a flat tube in the middle and round tubes at both ends. The electrical excitation system includes metal electrodes and a high-voltage AC power supply. Metal electrodes are mounted on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply is connected to the metal electrode on the upper side of the flat tube via a wire, and the ground terminal of the high-voltage AC power supply is connected to the metal electrode on the lower side of the flat tube and a ground wire via a wire. Sealing system assemblies are connected to both ends of the vacuum cavity. Each sealing system assembly includes a flange cylinder and a glass window. One end of the flange cylinder at each end is connected to the round tube of the vacuum cavity at the same end. The tube is sealed and connected, and a glass window is sealed and installed at the other end of the flange cylinder at each end. The gas supply system, vacuum pumping system, vacuum monitoring system and high pressure monitoring system are respectively connected to the flange cylinder. The pump and light output system includes a pump source, an optical isolator, a high-reflection mirror A, a focusing lens, a dichroic mirror, an output coupling mirror, a high-reflection mirror B, an optical fiber probe, an optical fiber and a spectrometer. The pump source laser emitted by the pump source passes through the optical isolator and is reflected by the high-reflection mirror A, and then passes through the focusing lens and the dichroic mirror in sequence before being projected into the vacuum cavity by the sealed system assembly at one end of the vacuum cavity. After passing through the discharge area of ​​the electrical excitation system, the laser is output by the sealed system assembly at the other end of the vacuum cavity. The output laser passes through the output coupling mirror and is reflected by the high-reflection mirror B before being projected into the optical fiber probe. The output wavelength and broadening are monitored by the spectrometer through the optical fiber.

[0010] Another structure of the present invention is a flat-round integrated dielectric barrier discharge semiconductor-pumped inert gas laser, comprising a vacuum cavity, an electrical excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-voltage monitoring system, and a pumping and light output system. The vacuum cavity is a hollow structure with a flat tube in the middle and round tubes at both ends. The electrical excitation system includes a corona discharge system and a dielectric barrier discharge system. The corona discharge system includes a needle electrode and a DC high-voltage power supply. The needle electrode is sealed and inserted into the flat tube of the vacuum cavity, with the tip inside the flat tube and the tail exposed outside, and connected to the DC high-voltage power supply. The dielectric barrier discharge system includes a metal electrode and a high-voltage AC power supply. Metal electrodes are installed on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply is connected to the metal electrode on the upper side of the flat tube via a wire, and the ground terminal of the high-voltage AC power supply is connected to the metal electrode and ground wire on the lower side of the flat tube via a wire. The negative voltage terminal of the DC high-voltage power supply is connected to the ground wire. Both ends of the vacuum cavity are connected to a sealing system assembly, which includes a flange cylinder and a glass window. One end of the flange cylinder at each end is sealed to the circular tube of the vacuum cavity on the same side, and the other end of the flange cylinder at each end is sealed with a glass window. The gas supply system, vacuum pumping system, vacuum monitoring system, and high-pressure monitoring system are respectively connected to the flange cylinder. The pumping and light output system includes a pump source, an optical isolator, a high-reflection mirror A, a focusing lens, a dichroic mirror, an output coupling mirror, a high-reflection mirror B, a fiber optic probe, an optical fiber, and a spectrometer. The pump source laser emitted by the pump source passes through the optical isolator and is reflected by the high-reflection mirror A, and then passes through the focusing lens and the dichroic mirror in sequence before being projected into the vacuum cavity by the sealing system assembly at one end of the vacuum cavity. After passing through the discharge region of the electrical excitation system, the laser is output from the sealing system assembly at the other end of the vacuum cavity. The output laser passes through the output coupling mirror and is reflected by the high-reflection mirror B before being projected into the fiber optic probe. The output wavelength and broadening are monitored by the spectrometer through the optical fiber.

[0011] Wherein: the needle electrode is a multi-pair double-row needle structure, that is, a row of needle electrodes is inserted at the same height on both sides of the flat tube of the vacuum cavity. The number of needle electrodes in the double-row needle electrodes is the same and corresponds one-to-one. Each needle electrode is inserted into the side wall of the flat tube and then sealed and fixed. The needle tips of each group of needle electrodes are opposite each other and the spacing is equal. The needle tails of one row of needle electrodes are connected in parallel to the positive voltage terminal of the DC high voltage power supply, and the needle tails of the other row of needle electrodes are connected in parallel to the negative voltage terminal of the DC high voltage power supply.

[0012] The gas supply system includes a buffer gas control gas supply system for supplying buffer gas into the vacuum chamber and a working medium gas control gas supply system for supplying working medium gas into the vacuum chamber. The buffer gas control gas supply system is connected to the first interface of the tee connector, the working medium gas control gas supply system is connected to the second interface of the tee connector, and the third interface of the tee connector is connected to the flange cylinder.

[0013] The buffer gas control supply system includes a buffer gas source, control valve A, and mass flow meter A. The buffer gas source is connected to the first port of a tee connector via a gas pipeline, and control valve A and mass flow meter A are installed on the gas pipeline. The working medium gas control supply system includes a working medium gas source, control valve B, and mass flow meter B. The working medium gas source is connected to the second port of a tee connector via another gas pipeline, and control valve B and mass flow meter B are installed on the other gas pipeline. Mass flow meter A and mass flow meter B are respectively connected to a flow controller.

[0014] The vacuum pumping system includes an adapter, a control valve C, and a vacuum pump. One end of the adapter is connected to a flange cylinder, and the vacuum pump is connected to the other end of the adapter through a vacuum pipeline. The control valve C is installed on the vacuum pipeline.

[0015] The vacuum monitoring system includes a vacuum gauge and a vacuum pressure display, which are connected to the flange cylinder.

[0016] The high-pressure monitoring system includes a high-pressure sensor and a high-pressure display, which are connected to the flange cylinder.

[0017] The flange cylinder has a front flange and a rear flange fixedly connected to both ends, and a hollow cylindrical tube for communicating with the gas supply system, vacuum pumping system, vacuum monitoring system and high pressure monitoring system is provided on the side wall of the flange cylinder; a cavity flange is fixedly connected to the cylindrical end of the vacuum cavity, and the cavity flange is sealed to the front flange; a window flange is connected to the rear flange, and the glass window is sealed and clamped between the rear flange and the window flange.

[0018] The cavity flange is connected to the front flange and the rear flange to the window flange by screws and nuts. A cavity sealing ring is provided between the cavity flange and the front flange for sealing. Window sealing rings are provided at both ends of the glass window for sealing.

[0019] The advantages and positive effects of this invention are as follows:

[0020] Existing technology designs the dielectric barrier discharge device and vacuum chamber separately, placing the entire device within a vacuum chamber filled with inert gas after gas replacement. However, due to the unique properties of inert gas, existing dielectric barrier discharge devices are prone to arcing between electrodes when high voltage is applied, making it difficult to form a stable, large-area discharge between the dielectrics, thus affecting the generation of metastable particles and the overall laser performance. Compared to traditional methods, this invention has the following advantages:

[0021] 1. The present invention has a simple structure and is easy to operate. By integrating the dielectric barrier discharge device (i.e., the electric excitation system) and the vacuum cavity into a single design, the complexity caused by the independent design of the dielectric barrier discharge device and the vacuum cavity is avoided, and the trouble of internal wiring in the vacuum cavity is also avoided.

[0022] 2. After the invention of the integrated design of dielectric barrier discharge device and vacuum cavity, the metal electrode of dielectric barrier discharge is in the air, avoiding direct contact with inert gas. Although the ionized gas is still inert gas, the arcing effect disappears and the discharge is stable when high voltage is supplied, thus ensuring that the metastable particle number is not affected and the laser operates effectively.

[0023] 3. This invention fully realizes continuous and stable discharge under high pressure and a higher metastable particle number concentration. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0026] Figure 3 This is a top view of the electrical excitation system according to Embodiment 2 of the present invention;

[0027] Wherein: 1 is the vacuum chamber, 2 is the metal electrode, 3 is the high-voltage AC power supply, 4 is the wire, 5 is the ground wire, 6 is the chamber flange, 7 is the window flange, 8 is the flange cylinder, 9 is the chamber sealing ring, 10 is the window sealing ring, 11 is the glass window, 12 is the front flange, 13 is the rear flange, 14 is the screw, 15 is the nut, 16 is the hollow cylindrical tube, 17 is the buffer gas source, 18 is the control valve A, 19 is the mass flow meter A, 20 is the working medium gas source, 21 is the control valve B, 22 is the mass flow meter B, 23 is the flow controller, 24 is the... 25 is a gas pipeline, 26 is a tee connector, 27 is an adapter connector, 28 is a control valve C, 29 is a vacuum pump, 30 is a vacuum gauge, 31 is a vacuum pressure display, 32 is a high-pressure sensor, 33 is a high-pressure display, 34 is a pump source, 35 is an optical isolator, 36 is a high-reflectivity mirror A, 37 is a dichroic mirror, 38 is an output coupling mirror, 39 is a high-reflectivity mirror B, 40 is a pump source laser, 41 is an emitted laser, 42 is a fiber optic probe, 43 is a fiber optic cable, 44 is a spectrometer, 45 is a needle electrode, and 46 is a DC high-voltage power supply. Detailed Implementation

[0028] The invention will now be described in further detail with reference to the accompanying drawings.

[0029] like Figure 1 As shown, this embodiment includes a vacuum chamber 1, an electric excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-pressure monitoring system, and a pumping and light-emitting system.

[0030] In this embodiment, the vacuum chamber 1 is a high-temperature and high-pressure resistant insulator. The material can be quartz glass, with a heat resistance temperature of up to 1200℃ and a pressure resistance value of up to 0.5Mpa. The vacuum chamber 1 has a hollow structure, with a flat tube in the middle and transitional hollow round tubes at both ends.

[0031] The electrical excitation system of this embodiment includes metal electrodes 2, a high-voltage AC power supply 3, wires 4, and a ground wire 5. Metal electrodes 2 are fixedly installed on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply 3 is connected to the metal electrode 2 on the upper side of the flat tube via wires 4. The ground terminal of the high-voltage AC power supply 3 is connected to the metal electrode 2 on the lower side of the flat tube and the ground wire 5 via wires 4. The metal electrodes 2 in this embodiment can be rectangular metal plates or sheets, and the material can be aluminum foil. The high-voltage AC power supply 3 in this embodiment is prior art, and its amplitude and frequency are adjustable.

[0032] Both ends of the vacuum chamber 1 are connected to a sealing system assembly, which includes a flange cylinder 8 and a glass window 11. One end of each flange cylinder 8 is sealed to the circular tube of the vacuum chamber 1 at the same end, and the other end of each flange cylinder 8 is sealed with a glass window 11. The gas supply system, vacuum pumping system, vacuum monitoring system, and high-pressure monitoring system are respectively connected to the flange cylinder 8. The gas supply system, vacuum pumping system, vacuum monitoring system, and high-pressure monitoring system can be connected to one flange cylinder 8 or two flange cylinders 8, and the number of systems connected to each flange cylinder 8 is not limited. In this embodiment, each flange cylinder 8 has two hollow cylindrical tubes 16 on its side wall. The two hollow cylindrical tubes 16 on the flange cylinder 8 at the left end are respectively connected to the gas supply system and the vacuum monitoring system, and the two hollow cylindrical tubes 16 on the flange cylinder 8 at the right end are respectively connected to the vacuum pumping system and the high-pressure monitoring system.

[0033] In this embodiment, the flange cylinder 8 is a hollow cylinder with a front flange 12 and a rear flange 13 welded to both ends. The material is metal, such as stainless steel, aluminum, or iron. The end of the vacuum chamber 1 is welded with a chamber flange 6. The chamber flange 6 is connected to the front flange 12 by screws 14 and nuts 15. A chamber sealing ring 9 for sealing is provided between the chamber flange 6 and the front flange 12. The rear flange 13 is connected to a window flange 7. The rear flange 13 and the window flange 7 are connected by screws 14 and nuts 15. The glass window 11 is clamped between the rear flange 13 and the window flange 7. A window sealing ring 10 for sealing is provided at both ends of the glass window 11.

[0034] In this embodiment, both the cavity flange 6 and the window flange 7 are hollow circular flanges made of metal, such as stainless steel, aluminum, or iron. The inner diameter of the cavity flange 6 is the same as the outer diameter of the circular tubes at both ends of the vacuum cavity 1, and the inner diameter of the window flange 7 is the same as the inner diameter of the circular tubes at both ends of the vacuum cavity 1. A circular groove is provided between the inner circle of the window flange 7 and the flange bolt hole on the opposite side of the rear flange 13. The size and shape of the front flange 12 are the same as those of the cavity flange 6. The outer diameter of the flange cylinder 8 is larger than the inner diameter of the cavity flange 6, and the inner diameter of the flange cylinder 8 is smaller than the inner diameter of the cavity flange 6. The size and shape of the rear flange 13 welded to the flange cylinder 8 are the same as those of the window flange 7. The side of the rear flange 13 facing the window flange 7 has a groove along the thickness direction for embedding the glass window 11. The diameter of this groove is larger than the outer diameter of the flange cylinder 8. A circular groove is also provided at the bottom of the groove along the thickness direction of the rear flange 13. Window sealing rings 10 are accommodated in the circular grooves on both the window flange 7 and the rear flange 13.

[0035] In this embodiment, the cavity sealing ring 9 is a circular rubber ring made of either fluororubber or nitrile rubber. The inner diameter of the cavity sealing ring 9 is consistent with the outer diameter of the circular tubes at both ends of the vacuum cavity 1. The cavity flange 6 and the cavity sealing ring 9 are fitted into the circular tubes at both ends of the vacuum cavity 1 and are fixedly sealed to the front flange 12 welded on the flange cylinder 8.

[0036] In this embodiment, the window sealing ring 10 is a circular rubber ring. The size and dimensions of the window sealing ring 10 are consistent with the circular groove on the window flange 7 and the circular groove on the rear flange 13. The thickness of the window sealing ring 10 is greater than the groove depth of the circular groove on the window flange and the circular groove on the rear flange 13. The window sealing ring 10 is inserted into the circular groove on the rear flange 13, the glass window is embedded in the groove on the rear flange 13, and the window sealing ring 10 is embedded in the circular groove on the window flange 7. Then, it is pressed tightly onto the glass window 11 and securely sealed with the rear flange 13.

[0037] In this embodiment, the glass window 11 is a circular double-coated quartz or gemstone with an outer diameter that matches the diameter of the groove on the rear flange 13. The thickness of the glass window 11 is greater than the depth of the groove on the rear flange 13.

[0038] The gas supply system of this embodiment includes a buffer gas control gas supply system for supplying buffer gas into the vacuum chamber 1 and a working medium gas control gas supply system for supplying working medium gas into the vacuum chamber 1. The buffer gas control gas supply system is connected to the first interface of the three-way connector 25, the working medium gas control gas supply system is connected to the second interface of the three-way connector 25, and the third interface of the three-way connector 25 is connected to the flange cylinder 8.

[0039] The buffer gas control supply system of this embodiment includes a buffer gas source 17, a control valve A18, and a mass flow meter A19. The buffer gas source 17 is connected to the first interface of a tee connector 25 via a gas pipeline 24, and the control valve A18 and mass flow meter A19 are installed on the gas pipeline 24. The working medium gas control supply system of this embodiment includes a working medium gas source 20, a control valve B21, and a mass flow meter B22. The working medium gas source 20 is connected to the second interface of a tee connector 25 via another gas pipeline 24, and the control valve B21 and mass flow meter B22 are installed on the other gas pipeline 24. Mass flow meters A19 and B22 are connected to a flow controller 23. The third interface of the tee connector 25 is connected to a hollow cylindrical pipe 16 located on the side wall of the flange cylinder 8 at the left end. In this embodiment, the buffer gas source in the gas supply system is helium, and the working medium gas source is one of argon, krypton, or xenon. The flow controller 23 is a commercially available dual-module controller manufactured by Beijing Qixing Huachuang Flowmeter Co., Ltd., which enables independent and precise flow control of mass flow meters A19 and B22. The gas pipeline 24 in the gas supply system is a rigid metal pipe or an insulated rigid pipe. The rigid metal pipe material can be one of stainless steel, copper, or iron, and the insulated rigid pipe material can be one of polytetrafluoroethylene or nylon. The tee connector 25 is one of a tee compression fitting or a tee flange connector. The control valves A18 and B21 in the gas supply system and the control valve C27 in the vacuum pumping system are one of a manual ball valve or a needle valve.

[0040] The vacuum pumping system of this embodiment includes an adapter 26, a control valve C27, and a vacuum pump 28. One end of the adapter 26 is connected to a hollow cylindrical tube 16 located on the side wall of the right-end flange cylinder 8. The vacuum pump 28 is connected to the other end of the adapter 26 through a vacuum pipeline, and the control valve C27 is installed on the vacuum pipeline. The adapter 26 in this embodiment is either a compression fitting or a flange fitting.

[0041] The vacuum monitoring system of this embodiment includes a vacuum gauge 29 and a vacuum pressure display 30, which are connected to another hollow cylindrical tube 16 located on the side wall of the left flange cylinder 8.

[0042] The high-pressure monitoring system of this embodiment includes a high-pressure sensor 31 and a high-pressure display 32, which are connected to another hollow cylindrical tube 16 located on the side wall of the right-end flange cylinder 8.

[0043] The pumping and light-emitting system of this embodiment includes a pump source 33, an optical isolator 34, a high-reflection mirror A35, a focusing lens 36, a dichroic mirror 37, an output coupling mirror 38, a high-reflection mirror B39, an optical fiber probe 42, an optical fiber 43, and a spectrometer 44. The pump source laser 40 emitted by the pump source 33 passes through the optical isolator 34 and is reflected by the high-reflection mirror A35, and then passes sequentially through the focusing lens 36 and the dichroic mirror 37 before being projected into the vacuum cavity 1 through the sealing system assembly at the right end of the vacuum cavity 1. After passing through the discharge region of the electrically excited system, the emitted laser 41 is output from the sealing system assembly at the left end of the vacuum cavity 1. The emitted laser 41 passes through the output coupling mirror 38 and is reflected by the high-reflection mirror B39 before being projected into the optical fiber probe 42. The output wavelength and broadening are monitored by the spectrometer 44 through the optical fiber 43.

[0044] In this embodiment, the pump source 33 in the pumping and light-emitting system is a narrow-linewidth wavelength semiconductor laser with adjustable output power. High-reflectivity mirrors A35 and B39 are gold-plated plane mirrors. High-reflectivity mirrors A35 and B39 are located at the left and right ends of the vacuum cavity 1 and are placed at 45°. The center line of high-reflectivity mirror A35 is perpendicular to the center line of high-reflectivity mirror B39 and is at 45° to the center line of the flat tube of the vacuum cavity 1. The center point of high-reflectivity mirror A35 and the center point of high-reflectivity mirror B39 are both located on the center line of the flat tube of the vacuum cavity 1.

[0045] In this embodiment, the focusing lens 36 is a plano-convex lens, and both sides of the plano-convex lens are coated with an anti-reflection film of the pump source laser wavelength, and the transmittance of the focusing lens is greater than 99.9%.

[0046] In this embodiment, the dichroic mirror 37 is a coated plane mirror, with an anti-reflection coating for the pump source laser wavelength and an anti-reflection coating for the emitted laser wavelength. The dichroic mirror 37 has a reflectivity of less than 0.1% for the pump source laser wavelength and a reflectivity of more than 99% for the emitted laser wavelength. The dichroic mirror 37 is placed between the sealing system assembly connected to the left end of the vacuum cavity 1 and the focusing lens 36, and the focusing lens 36 is placed between the dichroic mirror 37 and the high-reflectivity mirror A35.

[0047] In this embodiment, the output coupling mirror 38 is a coated plano-concave mirror with an anti-reflection coating for the pump source laser wavelength and an anti-reflection coating for the output laser wavelength. The output coupling mirror 38 has a reflectivity greater than 99.5% for the pump source laser wavelength and a transmittance greater than 99.5% for the output laser wavelength. The output coupling mirror 38 is placed between the sealing system assembly connected to the left end of the vacuum cavity 1 and the high-reflectivity mirror B. The high-reflectivity mirror A35, the focusing lens 36, and the dichroic mirror 37 are located at the right end of the vacuum cavity 1, while the high-reflectivity mirror B39 and the output coupling mirror 38 are located at the left end of the vacuum cavity 1.

[0048] In this embodiment, both sides of the glass window 11 are coated with an anti-reflection film of the pump source laser wavelength and an anti-reflection film of the emitted laser wavelength, and the transmittance of the glass window 11 is greater than 99.9%.

[0049] Example 2

[0050] like Figure 2 and Figure 3 As shown, the difference between this embodiment and Embodiment 1 is that the electrical excitation system in this embodiment includes a corona discharge system and a dielectric barrier discharge system. The corona discharge system includes a needle electrode 45 and a DC high-voltage power supply 46. The needle electrode 45 is sealed and inserted into the flat tube of the vacuum chamber 1. The tip of the needle electrode 45 is located inside the flat tube, and the tail of the needle is exposed outside the flat tube and connected to the DC high-voltage power supply 46. The dielectric barrier discharge system in this embodiment includes a metal electrode 2, a high-voltage AC power supply 3, a wire 4, and a ground wire 5. Metal electrodes 2 are installed on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply 3 is connected to the metal electrode 2 on the upper side of the flat tube through the wire 4. The ground terminal of the high-voltage AC power supply 3 is connected to the metal electrode 2 on the lower side of the flat tube and the ground wire 5 through the wire 4. At the same time, the negative voltage terminal of the DC high-voltage power supply 46 is connected to the ground wire 5. The metal electrode 2 in the dielectric barrier discharge system of the electrical excitation system in this embodiment can be a rectangular metal plate or metal sheet, and the material can be aluminum foil. The high-voltage AC power supply 3 and the DC high-voltage power supply 46 in this embodiment are both prior art. The amplitude and frequency of the high-voltage AC power supply 3 are adjustable.

[0051] In this embodiment, the needle electrode 45 is a multi-pair double-row needle structure, that is, a row of needle electrodes 45 is inserted at the same height on both sides of the flat tube of the vacuum cavity 1. The number of needle electrodes 45 in the double-row needle electrodes is the same and they correspond one-to-one. Each needle electrode 45 is inserted into the side wall of the flat tube and then sealed and fixed. The needle tips of each group of needle electrodes 45 are opposite each other and the spacing is equal. The needle tails of one row of needle electrodes in the double-row needle electrodes are connected in parallel to the positive voltage terminal of the DC high voltage power supply 46, and the needle tails of the other row of needle electrodes are connected in parallel to the negative voltage terminal of the DC high voltage power supply 46.

[0052] Everything else is the same as in Example 1.

[0053] The working principle of this invention is as follows:

[0054] Pump source laser 40 is incident on high-reflection mirror A35 after passing through optical isolator 34. High-reflection mirror A35 reflects the pump source laser 40 and projects it into the vacuum cavity 1 containing the electrically excited system via focusing lens 36 and dichroic mirror 37. The pump laser and the emitted laser 41 pass through output coupling mirror 38. The emitted laser 41 is reflected by high-reflection mirror B39 and projected into fiber optic probe 42, and then monitored by spectrometer 44 via fiber optic cable 43. Specifically:

[0055] Vacuum chamber 1 is made of high-temperature and high-pressure resistant quartz glass. Its shape consists of a hollow flat tube in the middle and hollow round tubes at both ends. The central flat tube is 60mm long and 55mm wide with a 3mm gap. The two transitional hollow round tubes are 70mm long, 40mm in outer diameter, and 3mm thick. Aluminum foil electrodes, 50mm long and 45mm wide, are placed on the upper and lower sides of the flat tube. One end of each aluminum foil electrode is connected to the output of a medium-frequency AC high-voltage power supply, and the other end is grounded. The transitional hollow round tubes at both ends of vacuum chamber 1 are sealed using stainless steel chamber flanges 6, flange cylinders 8, window flanges 7, and fluororubber sealing rings (i.e., window sealing rings 10). Flange cylinder 8 is 50mm long, with a front flange 12 and a rear flange 13 welded to both ends, each with an outer diameter of 70mm and a thickness of 5mm. The front flange 12 on the flange cylinder 8 is sealed to the cavity flange 6 via a fluororubber cavity sealing ring (i.e., cavity sealing ring 9). A fluororubber sealing ring is placed in the circular groove on the rear flange 13, and a quartz glass observation window (i.e., glass window 11) is placed in the groove. At the same time, a fluororubber sealing ring is also placed in the circular groove on the window flange 7, and is sealed to the rear flange 13 and the quartz glass observation window. Four stainless steel hollow cylindrical tubes 16 are welded to the side walls of the two flange cylinders 8 at both ends. The outer diameter of the hollow cylindrical tubes 16 is 6mm, and they are respectively connected to the gas supply system, the vacuum pumping system, the vacuum monitoring system, and the high-pressure monitoring system. The buffer gas used in the gas supply system is helium, and the working medium gas is argon. The two gas lines are connected to the mass flow meter via pressure reducing valves (i.e., control valve A18 and control valve B21) through PTFE rigid tubes and ferrules. The outlet of the mass flow meter is connected to the hollow cylindrical tube 16 on the side wall of the flange cylinder 8 through PTFE rigid tubes and tee fittings (i.e., tee fittings 25). The output flow rates of the two mass flow meters are regulated by the flow controller 23, enabling precise control of the flow ratio of the two gases. The vacuum pump 28 in the vacuum pumping system is connected to the hollow cylindrical tube 16 on the side wall of the flange cylinder 8 via a bellows, needle valve (i.e., control valve C27), and KF flange adapter (i.e., adapter 26). The vacuum gauge 29 in the vacuum monitoring system is connected to the hollow cylindrical tube 16 on the side wall of the flange cylinder 8 via the KF flange adapter, and the vacuum level is recorded and read by the vacuum pressure display 30. The high-pressure sensor 31 in the high-pressure monitoring system is connected to the hollow cylindrical tube 16 on the side wall of the flange cylinder 8 via the KF flange adapter, and its high-pressure value is read by the high-pressure display 32.

[0056] During operation, the vacuum pumping system first extracts air from the vacuum chamber 1, and the vacuum level in the vacuum chamber 1 is observed through the vacuum monitoring system. When the vacuum level reaches the set value, the gas supply system is turned on, and the flow ratio of buffer gas and working medium gas is controlled to 95%:5% through the mass flow meter and flow controller. At the same time, the needle valve in the vacuum pumping system is adjusted and the high pressure monitoring system is observed to keep the total gas pressure in the vacuum chamber 1 at 0.1 MPa. At this time, the high-voltage AC power supply 3 is turned on to supply power to generate plasma and the required argon metastable particles.

[0057] The pump source 33 used is a narrow-linewidth dye laser with an output wavelength of 811.5 nm and an energy of 20 mJ. After the pump source laser 40 is oriented by the high-reflectivity mirror A35 placed at 45°, the laser is incident perpendicularly to the discharge region in the vacuum cavity 1 through the focusing lens 36 and the dichroic mirror 37. The argon metastable particles generated by the discharge absorb energy through the pump to produce a 912 nm laser. The dichroic mirror 37 and the output coupling mirror 38 constitute the optical cavity of the 912 nm laser. The generated 912 nm laser will be output through the output coupling mirror 38 and enter the spectrometer 44 for detection via the high-reflectivity mirror B39.

Claims

1. A flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser, characterized in that: The system includes a vacuum chamber (1), an electric excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-voltage monitoring system, and a pumping and light-emitting system. The vacuum chamber (1) has a hollow structure with a flat tube in the middle and round tubes at both ends. The electric excitation system includes metal electrodes (2) and a high-voltage AC power supply (3). Metal electrodes (2) are installed on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply (3) is connected to the metal electrode (2) on the upper side of the flat tube through a wire (4). The grounding terminal of the high-voltage AC power supply (3) is connected to the metal electrode (2) and ground wire (5) on the lower side of the flat tube via a wire (4); both ends of the vacuum chamber (1) are connected to a sealing system assembly, which includes a flange cylinder (8) and a glass window (11). One end of the flange cylinder (8) at each end is sealed to the round tube of the vacuum chamber (1) at the same end, and the other end of the flange cylinder (8) at each end is sealed with a glass window (11). The gas supply system and vacuum pumping system are connected to the vacuum chamber (1) at the same end. The system, vacuum monitoring system, and high-pressure monitoring system are respectively connected to the flange cylinder (8); the pump and light output system includes a pump source (33), an optical isolator (34), a high-reflection mirror A (35), a focusing lens (36), a dichroic mirror (37), an output coupling mirror (38), a high-reflection mirror B (39), an optical fiber probe (42), an optical fiber (43), and a spectrometer (44). The pump source laser (40) emitted by the pump source (33) passes through the optical isolator (34) and then through the high-reflection mirror A (35). After reflection, the laser beam passes through a focusing lens (36) and a dichroic mirror (37) in sequence and is then projected into the vacuum cavity (1) through a sealing system assembly at one end of the vacuum cavity (1). After passing through the discharge area of ​​the electro-excitation system, the laser beam (41) is output from the sealing system assembly at the other end of the vacuum cavity (1). The laser beam (41) passes through an output coupling mirror (38) and is reflected by a high-reflection mirror B (39) before being projected into an optical fiber probe (42). The output wavelength and broadening are monitored by a spectrometer (44) through the optical fiber (43).

2. A flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser, characterized in that: The system includes a vacuum chamber (1), an electric excitation system, a sealing system assembly, a gas supply system, a vacuum pumping system, a vacuum monitoring system, a high-voltage monitoring system, and a pumping and light-emitting system. The vacuum chamber (1) is a hollow structure with a flat tube in the middle and round tubes at both ends. The electric excitation system includes a corona discharge system and a dielectric barrier discharge system. The corona discharge system includes a needle electrode (45) and a DC high-voltage power supply (46). The needle electrode (45) is sealed and inserted into the flat tube of the vacuum chamber (1). The tip of the needle electrode (45) is located inside the flat tube, and the tail is exposed outside the flat tube and connected to the DC high-voltage power supply (46). The dielectric barrier discharge system includes metal electrodes (2) and a high-voltage AC power supply (3). Metal electrodes (2) are installed on both the upper and lower sides of the flat tube. The high-voltage output terminal of the high-voltage AC power supply (3) is connected to the metal electrode (2) on the upper side of the flat tube via a wire (4). The grounding terminal of the high-voltage AC power supply (3) is connected to the metal electrode (2) on the lower side of the flat tube and a ground wire (5) via a wire (4). The negative voltage terminal of the DC high-voltage power supply (46) is connected to the ground wire (5). Both ends of the vacuum chamber (1) are connected to sealing system components. The sealing system components include a flange cylinder (8) and a glass window (11). One end of each flange cylinder (8) is sealed to the circular tube of the vacuum chamber (1) on the same side, and the other end of each flange cylinder (8) is sealed with a glass window (11). The gas supply system, vacuum pumping system, vacuum monitoring system and high pressure monitoring system are respectively connected to the flange cylinder (8). The pump and light output system includes a pump source (33), an optical isolator (34), a high-reflection mirror A (35), a focusing lens (36), a dichroic mirror (37), an output coupling mirror (38), a high-reflection mirror B (39), an optical fiber probe (42), an optical fiber (43) and a spectrometer (44), which are powered by the pump. The pump source laser (40) emitted by the source (33) passes through the optical isolator (34) and is reflected by the high-reflection mirror A (35). Then, it passes through the focusing lens (36) and the dichroic mirror (37) in sequence and is projected into the vacuum cavity (1) through the sealing system assembly at one end of the vacuum cavity (1). After passing through the discharge area of ​​the electric excitation system, the output laser (41) is output from the sealing system assembly at the other end of the vacuum cavity (1). The output laser (41) passes through the output coupling mirror (38) and is reflected by the high-reflection mirror B (39) and is projected into the fiber optic probe (42). The output wavelength and broadening are monitored by the spectrometer (44) through the fiber optic cable (43).

3. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 2, characterized in that: The needle electrode (45) is a multi-pair double-row needle structure, that is, a row of needle electrodes (45) is inserted at the same height on both sides of the flat tube of the vacuum cavity (1). The number of needle electrodes (45) in the double-row needle electrodes is the same and corresponds one-to-one. Each needle electrode (45) is inserted into the side wall of the flat tube and then sealed and fixed. The needle tips of each group of needle electrodes (45) are opposite each other and the spacing is equal. The needle tails of one row of needle electrodes in the double-row needle electrodes are connected in parallel to the positive voltage end of the DC high voltage power supply (46), and the needle tails of the other row of needle electrodes are connected in parallel to the negative voltage end of the DC high voltage power supply (46).

4. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 1 or 2, characterized in that: The gas supply system includes a buffer gas control gas supply system for supplying buffer gas into the vacuum chamber (1) and a working medium gas control gas supply system for supplying working medium gas into the vacuum chamber (1). The buffer gas control gas supply system is connected to the first interface of the three-way connector (25), the working medium gas control gas supply system is connected to the second interface of the three-way connector (25), and the third interface of the three-way connector (25) is connected to the flange cylinder (8).

5. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 4, characterized in that: The buffer gas control supply system includes a buffer gas source (17), a control valve A (18), and a mass flow meter A (19). The buffer gas source (17) is connected to the first interface of a three-way connector (25) through a gas pipeline (24), and the control valve A (18) and the mass flow meter A (19) are installed on the gas pipeline (24). The working medium gas control supply system includes a working medium gas source (20), a control valve B (21), and a mass flow meter B (22). The working medium gas source (20) is connected to the second interface of a three-way connector (25) through another gas pipeline (24), and the control valve B (21) and the mass flow meter B (22) are installed on the other gas pipeline (24). The mass flow meter A (19) and the mass flow meter B (22) are connected to a flow controller (23).

6. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 1 or 2, characterized in that: The vacuum pumping system includes an adapter (26), a control valve C (27), and a vacuum pump (28). One end of the adapter (26) is connected to the flange cylinder (8), and the vacuum pump (28) is connected to the other end of the adapter (26) through a vacuum pipeline. The control valve C (27) is installed on the vacuum pipeline.

7. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 1 or 2, characterized in that: The vacuum monitoring system includes a vacuum gauge (29) and a vacuum pressure display (30), which are connected to the flange cylinder (8).

8. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 1 or 2, characterized in that: The high pressure monitoring system includes a high pressure sensor (31) and a high pressure display (32), which are connected to the flange cylinder (8).

9. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 1 or 2, characterized in that: The flange cylinder (8) is fixedly connected to a front flange (12) and a rear flange (13) at both ends. The side wall of the flange cylinder (8) is provided with a hollow cylindrical tube (16) for communicating with the gas supply system, vacuum pumping system, vacuum monitoring system and high pressure monitoring system. The end of the circular tube of the vacuum cavity (1) is fixedly connected to a cavity flange (6), and the cavity flange (6) is sealed to the front flange (12). The rear flange (13) is connected to a window flange (7), and the glass window (11) is sealed and clamped between the rear flange (13) and the window flange (7).

10. The flat-circle integrated structure dielectric barrier discharge semiconductor-pumped inert gas laser according to claim 9, characterized in that: The cavity flange (6) and the front flange (12) are connected by screws (14) and nuts (15), and the rear flange (13) and the window flange (7) are connected by screws (14) and nuts (15). A cavity sealing ring (9) for sealing is provided between the cavity flange (6) and the front flange (12), and a window sealing ring (10) for sealing is provided at both ends of the glass window (11).

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