A multi-wavelength output dual-cycle optical-pumped Xe laser

Abstract

The application provides a multi-wavelength output double-circulation optical pumping Xe laser, which uses metastable Kr generated by gas discharge as an energy source, transmits energy by collision with ground state Xe to realize inversion in Xe system; meanwhile, uses two laser beams of 882nm and 828nm as pumping sources to maintain particle number inversion of Xe system and output multiple laser wavelengths. The application fully utilizes the effect of buffer gas Kr, realizes acceleration of collision relaxation process between energy levels and also plays a role in resonance energy transmission; the method effectively improves the utilization rate of Xe primary discharge particles, further improves the efficiency of optical pumping inert gas metastable state laser, and realizes primary electric pumping and multiple optical circulation.

Description

Technical Field

[0001] This invention relates to the fields of laser technology and inert gas discharge technology, and more particularly to the generation of highly efficient optically pumped inert gas lasers through the interaction of laser light with a discharge medium. Specifically, it relates to a multi-wavelength output dual-cycle optically pumped Xe laser. Background Technology

[0002] Optically pumped metastable inert gas lasers have gradually gained widespread attention due to their advantages such as high quantum efficiency, good beam quality, and inert gain medium. This laser system primarily uses Ar, Kr, and Xe atoms as gain media. Its operation begins by generating a large number of first excited-state particles s[3 / 2]2 through discharge. Because the transition from this energy level to the ground state is forbidden and collisional excitation is weak, its lifetime is long, hence the name metastable. Subsequently, a near-infrared laser is used to excite it to the p[5 / 2]3 energy level. By adding a buffer gas (usually He) for collisional transfer, the excited-state particles rapidly transfer from the pump upper energy level to the laser upper energy level p[1 / 2]1, achieving population inversion and outputting laser light. A schematic diagram of the rare gas laser system is shown below. Figure 1 As shown.

[0003] pass Figure 1 It can be observed that during the pump cycle, while outputting laser, the upper energy level of the laser will also radiate to the s[3 / 2]1 energy level, and this energy level will further transfer particles to the ground state ultraviolet radiation, thereby causing particle loss and resulting in low overall efficiency. Summary of the Invention

[0004] To address the aforementioned technical problem of low overall efficiency due to particle loss during the pump cycle, this invention provides a multi-wavelength output dual-cycle optically pumped Xe laser. By employing dual-cycle pumping, s[3 / 2]1 is pumped in a cycle, which fundamentally reduces particle waste and achieves highly efficient laser output.

[0005] The technical means employed in this invention are as follows:

[0006] A multi-wavelength output dual-cycle optically pumped Xe laser, comprising:

[0007] The system includes a first pump laser source, a second pump laser source, a dichroic mirror, a total reflection mirror, an output coupling mirror, a mixed gas discharge device, and a gas cell. The gas cell is used to hold a mixed gas of Kr and Xe and is disposed between the output coupling mirror and the total reflection mirror.

[0008] One of the first pump laser source and the second pump laser source is used to emit a pump laser with a wavelength of 828nm, and the other is used to emit a pump laser with a wavelength of 882nm.

[0009] The excitation method of the multi-wavelength output dual-cycle optically pumped Xe laser is as follows:

[0010] The mixed gas is excited by discharge, which generates Kr particles at the 5s[3 / 2]2 energy level and Xe particles at the 6s[3 / 2]2 energy level. The Kr particles at the 5s[3 / 2]2 energy level and the ground state Xe collide and generate Xe particles at the 6p[1 / 2]0 and 5d[1 / 2]1 energy levels through near-resonance energy transfer. The Xe particles at the 5d[1 / 2]1 energy level serve as the upper energy level of the laser and achieve population inversion with the Xe particles at the 6p[1 / 2]1 energy level, which serve as the lower energy level of the laser, to output a 3680nm laser.

[0011] Simultaneously, 882nm and 828nm lasers are used to pump the excited-state Xe generated by the discharge. The 828nm laser pumps the Xe particles located at energy level 6s[3 / 2]1 to Xe particles located at energy level 6p[1 / 2]0. After collisional relaxation by buffer gas Kr, the Xe particles located at energy level 6p[1 / 2]0 are relaxed to Xe particles located at energy level 5d[1 / 2]1. The Xe particles located at energy level 5d[1 / 2]1 are used as the upper energy level of the laser. Using Xe particles at energy level 6p[1 / 2]1 as the lower energy level, a 3680nm laser is generated. Then, using the generated Xe particles at energy level 6p[1 / 2]1 as the upper energy level and Xe particles at energy level 6s[3 / 2]1 as the lower energy level, a 1084nm laser output is achieved. Using Xe particles at energy level 6p[1 / 2]1 as the upper energy level and Xe particles at energy level 6s[3 / 2]2 as the lower energy level, a 980nm laser output is achieved.

[0012] An 882nm laser is used to pump Xe particles at energy level 6s[3 / 2]2 to Xe particles at energy level 6p[5 / 2]3. After passing through a buffer gas Kr, the Xe particles at energy level 6p[5 / 2]3 undergo collisional relaxation to Xe particles at energy level 6p[5 / 2]2. Using the Xe particles at energy level 6p[5 / 2]2 as the upper energy level of the laser and the Xe particles at energy level 6s[3 / 2]1 as the lower energy level, a 992nm laser output is achieved. Using the Xe particles at energy level 6p[5 / 2]2 as the upper energy level of the laser and the Xe particles at energy level 6s[3 / 2]2 as the lower energy level, a 904nm laser output is achieved.

[0013] An 828nm laser is used to pump Xe particles located at energy level 6s[3 / 2]1 to Xe particles located at energy level 6p[1 / 2]0, and an 882nm laser is used to pump Xe particles located at energy level 6s[3 / 2]2 to Xe particles located at energy level 6p[5 / 2]3. This pumps the particles from the lower energy level to the upper energy level of the laser, maintains the population inversion state, and achieves stable laser output for a long time.

[0014] Furthermore, the gain medium uses Kr and Xe with a total pressure of 50-760 Torr and a pressure ratio of 1:2-10:1.

[0015] Furthermore, the laser output spectrum of the laser includes:

[0016] A 3680nm laser with 5d[1 / 2]1 as the upper energy level and 6p[1 / 2]1 as the lower energy level;

[0017] A 980nm laser with 6p[1 / 2]1 as the upper energy level and 6s[3 / 2]2 as the lower energy level;

[0018] A 1084nm laser with 6p[1 / 2]1 as the upper energy level and 6s[3 / 2]1 as the lower energy level;

[0019] A 904nm laser with 6p[5 / 2]2 as the upper energy level and 6s[3 / 2]2 as the lower energy level;

[0020] A 992nm laser with 6p[5 / 2]2 as the upper energy level and 6s[3 / 2]1 as the lower energy level.

[0021] Furthermore, the wavelength of the laser output is determined by adjusting the thin films of the output coupling mirror and the reflector.

[0022] Furthermore, the energy ratio of the output laser at each wavelength is controlled by adjusting the energy of the 828nm pump laser and the 882nm pump laser.

[0023] Furthermore, the mixed gas discharge device (106) is a radio frequency discharge device or a high-voltage pulse discharge power supply.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] This invention uses dual-cycle pumping and the special energy level structure of the Kr-Xe system to pump s[3 / 2]1 in a cycle, which can greatly reduce the waste of particles; through the special energy level structure of the Kr-Xe system, the metastable state of the buffer gas Kr is fully utilized, thereby achieving efficient multi-wavelength laser output. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the operation of an optically pumped rare gas laser. In the diagram: 1-discharge process, 2-laser pumping process, 3-collision relaxation process, 4-output laser process, 5-loss radiation process, 6-loss ultraviolet radiation process.

[0028] Figure 2 This is a schematic diagram of the operation mode of the multi-wavelength dual-cycle optically pumped Xe laser of the present invention. In the figure: 1-discharge process, 2, 3, 4-collision relaxation process, 5-828nm pump laser source, 6-882nm pump laser source, 7-3680nm laser, 8-980nm laser, 9-1084nm laser, 10-904nm laser, 11-992nm laser.

[0029] Figure 3 This is a schematic diagram of the operation of the radio frequency discharge multi-wavelength dual-cycle optically pumped Xe laser of the present invention. In the figure: 101-828nm pump laser source, 102-882nm pump laser source, 103-dichroic mirror, 104-total reflection mirror, 105-output coupling mirror, 106-mixed gas radio frequency discharge device, 107-gas pool containing mixed gas.

[0030] Figure 4 The diagram below shows the working mode of the high-voltage pulsed discharge multi-wavelength dual-cycle optically pumped Xe laser of the present invention. In the diagram: 101-828nm pump excitation source, 102-882nm pump excitation source, 103-dichroic mirror, 104-total reflection mirror, 105-output coupling mirror, 106-mixed gas high-voltage pulsed discharge device, 107-gas pool containing mixed gas. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this invention can be combined with each other. The invention will now be described in detail with reference to the accompanying drawings and embodiments. To make the objectives, technical solutions, and advantages of the embodiments of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] like Figure 3 As shown, this invention provides a multi-wavelength output dual-cycle optically pumped Xe laser, comprising two pump laser sources, a mixed gas discharge device, an output coupling mirror, a laser gain medium, and a reflector. The laser gain medium is disposed between the output coupling mirror and the reflector, and is a mixed gas of Kr and Xe. The multi-wavelength output dual-cycle optically pumped Xe laser is excited by discharging the mixed gas, while simultaneously using an 828nm laser beam and an 882nm laser beam to pump the Xe laser medium.

[0033] Furthermore, the mixed gas is excited by discharge, which generates Kr(5s[3 / 2]2) and Xe(6s[3 / 2]2) particles. Kr(5s[3 / 2]2) and ground-state Xe collide and generate Xe(6p[1 / 2]0 and 5d[1 / 2]1) through near-resonance energy transfer. Xe(5d[1 / 2]1) serves as the upper energy level of the laser and can achieve population inversion with Xe(6p[1 / 2]1) which serves as the lower energy level of the laser, thus outputting a 3680nm laser.

[0034] Simultaneously, 882nm and 828nm lasers are used to pump the excited state Xe generated by the discharge. Among them, the 828nm laser pumps Xe(6s[3 / 2]1) to Xe(6p[1 / 2]0), and after collisional relaxation by buffer gas Kr, Xe(6p[1 / 2]0) can be relaxed to Xe(5d[1 / 2]1). Xe(5d[1 / 2]1) is used as the upper energy level of the laser and Xe(6p[1 / 2]1) is used as the lower energy level to generate a 3680nm laser. Then, the generated Xe(6p[1 / 2]1) is used as the upper energy level and Xe(6s[3 / 2]1) is used as the lower energy level to achieve a 1084nm laser output. With Xe(6p[1 / 2]1) as the upper energy level and Xe(6s[3 / 2]2) as the lower energy level, a 980nm laser output is achieved.

[0035] An 882nm laser is used to pump Xe(6s[3 / 2]2) to Xe(6p[5 / 2]3). After passing through a buffer gas Kr, Xe(6p[5 / 2]3) is collisionally relaxed to Xe(6p[5 / 2]2). Xe(6p[5 / 2]2) is used as the upper energy level of the laser and Xe(6s[3 / 2]1) is used as the lower energy level to achieve 992nm laser output. Xe(6p[5 / 2]2) is used as the upper energy level of the laser and Xe(6s[3 / 2]2) is used as the lower energy level to achieve 904nm laser output.

[0036] By using a laser with a wavelength of 828 nm to pump Xe(6s[3 / 2]1) to Xe(6p[1 / 2]0) and a laser with a wavelength of 882 nm to pump Xe(6s[3 / 2]2) to Xe(6p[5 / 2]3, the particles of the lower laser energy level are pumped to the upper laser energy level, maintaining the population inversion state and achieving long-term stable laser output.

[0037] Furthermore, the laser gain medium uses Kr and Xe with a total pressure of 50-760 Torr, P Kr :P Xe The ratio range is 1:2-10:1. The laser output spectrum of the laser includes five laser lines with 5d[1 / 2]1, 6p[1 / 2]1, and 6p[5 / 2]2 as the upper energy levels; that is:

[0038] 3680nm(5d[1 / 2]1→6p[1 / 2]1),

[0039] 980nm (6p[1 / 2]1→6s[3 / 2]2),

[0040] 1084nm(6p[1 / 2]1→6s[3 / 2]1),

[0041] 904nm (6p[5 / 2]2→6s[3 / 2]2),

[0042] 992nm(6p[5 / 2]2→6s[3 / 2]1).

[0043] The wavelength of the output laser can be selected by using appropriate thin films for the output coupling mirror and the reflector. The energy ratio of the output laser at each wavelength can be controlled by adjusting the energy of the 828nm pump laser and the 882nm pump laser.

[0044] The following specific application examples will further illustrate the solution of the present invention.

[0045] Example 1

[0046] like Figure 3As shown, a discharge electrode is added to the gas cell and an AC RF discharge power supply is applied to it. The effective gain region is 20cm and the discharge power is 1.2kW. The gas cell is connected by a Bush window in the light transmission direction, and both the front and rear windows are sealed with sapphire windows. The gas cell is filled with a Kr and Xe mixed gas with a total pressure of 500Torr and a Kr to Xe partial pressure ratio of 5:1. The distance between the output coupling mirror and the plano-concave total reflection mirror is 30cm, and the curvature of the plano-concave total reflection mirror is 30cm. After the mixed gas discharges, metastable Kr(5s[3 / 2]2) and Xe(6s[3 / 2]2) are generated. Through near-resonant energy transfer and pumping with 10W 882nm and 1W 828nm continuous lasers, population inversion is achieved in the Xe system, that is, the discharge region becomes the gain region. A resonant cavity is formed between the output coupling mirror and the plano-concave total reflection mirror, and laser is output. Different wavelength laser outputs are achieved by adjusting the film system of the coupling mirror.

[0047] The output coupling mirrors used have an output coupling rate of 3% (3680nm), outputting a laser with a wavelength of 3680nm and a power of 500mW; the output coupling mirrors used have an output coupling rate of 3% (980nm), outputting a laser with a wavelength of 980nm and a power of 100mW; the output coupling mirrors used have an output coupling rate of 3% (904nm), outputting a laser with a wavelength of 904nm and a power of 0.8W; the output coupling mirrors used have an output coupling rate of 3% (992nm), outputting a laser with a wavelength of 992nm and a power of 1.2W; and the output coupling mirrors used have an output coupling rate of 3% (1084nm), outputting a laser with a wavelength of 1084nm and a power of 10mW.

[0048] Example 2

[0049] Using a high-voltage pulse discharge power supply as the excitation source, such as Figure 4As shown. The implementation conditions are as follows: pulsed dielectric barrier discharge is used, the discharge voltage is 2000V, the frequency is 1KHz, the total gas pressure is 500Torr, and the voltage division ratio of Kr and Xe is 5:1. The distance between the output coupling mirror and the plano-concave total reflection mirror is 30cm, and the curvature of the plano-concave total reflection mirror is 30cm. Referring to Example 1 for other steps, the results obtained by pumping with 10W 882nm and 1W 828nm continuous lasers are as follows: The output coupling rate of the output coupling mirror is 3% (3680nm), and the output wavelength is 3680nm with a power of 800mW; the output coupling rate of the output coupling mirror is 3% (980nm), and it can output a laser with a wavelength of 980nm and a power of 150mW; the output coupling rate of the output coupling mirror is 3% (904nm), and it can output a laser with a wavelength of 904nm and a power of 1.2W; the output coupling rate of the output coupling mirror is 3% (992nm), and it can output a laser with a wavelength of 992nm and a power of 1.8W; the output coupling rate of the output coupling mirror is 3% (1084nm), and it can output a laser with a wavelength of 1084nm and a power of 20mW.

[0050] Example 3

[0051] like Figure 3 As shown, a discharge electrode was added to the gas cell, and an AC RF power supply was applied to it. The effective gain region was 20 cm, and the discharge power was 1.2 kW. The gas cell was connected by a Bush window in the light transmission direction, and both the front and rear windows were sealed with sapphire windows. The gas cell was filled with a Kr and Xe mixed gas with a total pressure of 500 Torr and a Kr to Xe voltage ratio of 5:1. The distance between the output coupling mirror and the plano-concave total reflection mirror was 30 cm, and the curvature of the plano-concave total reflection mirror was 30 cm. After the mixed gas was discharged, metastable Kr(5s[3 / 2]2) and Xe(6s[3 / 2]2) were generated. The mixture was pumped by near-resonant energy transfer and by 100 mW 882 nm and 30 mW 828 nm continuous lasers. The specific results are as follows:

[0052] The output coupling mirrors used have an output coupling rate of 5% (3680nm), outputting a laser with a wavelength of 3680nm and a power of 300mW; the output coupling mirrors used have an output coupling rate of 5% (980nm), outputting a laser with a wavelength of 980nm and a power of 60mW; the output coupling mirrors used have an output coupling rate of 5% (904nm), outputting a laser with a wavelength of 904nm and a power of 0.6W; the output coupling mirrors used have an output coupling rate of 5% (992nm), outputting a laser with a wavelength of 992nm and a power of 1W; the output coupling mirrors used have an output coupling rate of 5% (1084nm), outputting a laser with a wavelength of 1084nm and a power of 7mW.

[0053] Example 4

[0054] like Figure 3 As shown, a discharge electrode was added to the gas cell, and an AC RF power supply was applied to it. The effective gain region was 20 cm, and the discharge power was 1.2 kW. The gas cell was connected by a Bush window in the light transmission direction, and both the front and rear windows were sealed with sapphire windows. The gas cell was filled with a Kr and Xe mixed gas with a total pressure of 500 Torr and a Kr to Xe voltage ratio of 5:1. The distance between the output coupling mirror and the plano-concave total reflection mirror was 30 cm, and the curvature of the plano-concave total reflection mirror was 30 cm. After the mixed gas was discharged, metastable Kr(5s[3 / 2]2) and Xe(6s[3 / 2]2) were generated. The mixture was pumped by near-resonant energy transfer and by 100 mW 882 nm and 30 mW 828 nm continuous lasers. The specific results are as follows:

[0055] The output coupling mirrors used have an output coupling rate of 5% (3680nm), outputting a laser with a wavelength of 3680nm and a power of 300mW; the output coupling mirrors used have an output coupling rate of 5% (980nm), outputting a laser with a wavelength of 980nm and a power of 60mW; the output coupling mirrors used have an output coupling rate of 5% (904nm), outputting a laser with a wavelength of 904nm and a power of 0.6W; the output coupling mirrors used have an output coupling rate of 5% (992nm), outputting a laser with a wavelength of 992nm and a power of 1W.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-wavelength output dual-cycle optically pumped Xe laser, characterized in that, include: The system comprises a first pump laser source (101) and a second pump laser source (102), a dichroic mirror (103), a total reflection mirror (104), an output coupling mirror (105), a mixed gas discharge device (106), and a gas cell (107), wherein the gas cell (107) is used to hold a mixed gas of Kr and Xe and is disposed between the output coupling mirror (105) and the total reflection mirror (104); One of the first pump laser source (101) and the second pump laser source (102) is used to emit a pump laser with a wavelength of 828nm, and the other is used to emit a pump laser with a wavelength of 882nm. The excitation method of the multi-wavelength output dual-cycle optically pumped Xe laser is as follows: The mixed gas is excited by discharge, which generates Kr particles at the 5s[3 / 2]2 energy level and Xe particles at the 6s[3 / 2]2 energy level. The Kr particles at the 5s[3 / 2]2 energy level and the ground state Xe collide and generate Xe particles at the 6p[1 / 2]0 and 5d[1 / 2]1 energy levels through near-resonance energy transfer. The Xe particles at the 5d[1 / 2]1 energy level serve as the upper energy level of the laser and achieve population inversion with the Xe particles at the 6p[1 / 2]1 energy level, which serve as the lower energy level of the laser, to output a 3680nm laser. Simultaneously, 882nm and 828nm lasers are used to pump the excited-state Xe generated by the discharge. The 828nm laser pumps the Xe particles located at energy level 6s[3 / 2]1 to Xe particles located at energy level 6p[1 / 2]0. After collisional relaxation by buffer gas Kr, the Xe particles located at energy level 6p[1 / 2]0 are relaxed to Xe particles located at energy level 5d[1 / 2]1. The Xe particles located at energy level 5d[1 / 2]1 are used as the upper energy level of the laser. Using Xe particles at energy level 6p[1 / 2]1 as the lower energy level, a 3680nm laser is generated. Then, using the generated Xe particles at energy level 6p[1 / 2]1 as the upper energy level and Xe particles at energy level 6s[3 / 2]1 as the lower energy level, a 1084nm laser output is achieved. Using Xe particles at energy level 6p[1 / 2]1 as the upper energy level and Xe particles at energy level 6s[3 / 2]2 as the lower energy level, a 980nm laser output is achieved. An 882nm laser is used to pump Xe particles at energy level 6s[3 / 2]2 to Xe particles at energy level 6p[5 / 2]3. After passing through a buffer gas Kr, the Xe particles at energy level 6p[5 / 2]3 undergo collisional relaxation to Xe particles at energy level 6p[5 / 2]2. Using the Xe particles at energy level 6p[5 / 2]2 as the upper energy level of the laser and the Xe particles at energy level 6s[3 / 2]1 as the lower energy level, a 992nm laser output is achieved. Using the Xe particles at energy level 6p[5 / 2]2 as the upper energy level of the laser and the Xe particles at energy level 6s[3 / 2]2 as the lower energy level, a 904nm laser output is achieved. An 828nm laser is used to pump Xe particles located at energy level 6s[3 / 2]1 to Xe particles located at energy level 6p[1 / 2]0, and an 882nm laser is used to pump Xe particles located at energy level 6s[3 / 2]2 to Xe particles located at energy level 6p[5 / 2]3. This pumps the particles from the lower energy level to the upper energy level of the laser, maintains the population inversion state, and achieves stable laser output for a long time.

2. The multi-wavelength output dual-cycle optically pumped Xe laser according to claim 1, characterized in that, The gain medium uses Kr and Xe with a total pressure of 50-760 Torr and a pressure ratio of 1:2-10:

1.

3. The multi-wavelength output dual-cycle optically pumped Xe laser according to claim 1, characterized in that, The laser output spectral lines of the laser include: A 3680nm laser with 5d[1 / 2]1 as the upper energy level and 6p[1 / 2]1 as the lower energy level; A 980nm laser with 6p[1 / 2]1 as the upper energy level and 6s[3 / 2]2 as the lower energy level; A 1084nm laser with 6p[1 / 2]1 as the upper energy level and 6s[3 / 2]1 as the lower energy level; A 904nm laser with 6p[5 / 2]2 as the upper energy level and 6s[3 / 2]2 as the lower energy level; A 992nm laser with 6p[5 / 2]2 as the upper energy level and 6s[3 / 2]1 as the lower energy level.

4. A multi-wavelength output dual-cycle optically pumped Xe laser according to claim 1, characterized in that, The wavelength of the laser output is selected by adjusting the thin films of the output coupling mirror and the reflector.

5. A multi-wavelength output dual-cycle optically pumped Xe laser according to claim 1, characterized in that, The energy ratio of the output laser at each wavelength is controlled by adjusting the energy of the 828nm pump laser and the 882nm pump laser.

6. A multi-wavelength output dual-cycle optically pumped Xe laser according to claim 1, characterized in that, The mixed gas discharge device (106) is a radio frequency discharge device or a high-voltage pulse discharge power supply.

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