Diode-pumped rare gas lasers are potential candidates for high-energy and high-beam quality laser systems. Currently, most investigations are focused on metastable Ar lasers. The Kr system has the unique advantages of higher quantum efficiency and lower discharge requirements for comparison. In this paper, a diode-pumped metastable Kr laser was demonstrated for the first time. Using a repetitively pulsed discharge at a Kr/He pressure of up to approximately 1500 Torr, metastable Kr atoms of more than 10¹³ cm^–3 were generated. Under diode pumping, the laser realized a dual-wavelength output with an average output power of approximately 100 mW and an optical conversion efficiency of approximately 10% with respect to the absorbed pump power. A kinetics study involving population distribution and evolution was conducted to analyze the laser performance.

We report here the first hundred-watt continuous wave fiber gas laser in H₂-filled hollow-core photonic crystal fiber (PCF) by stimulated Raman scattering. The pump source is a homemade narrow-linewidth fiber oscillator with a 3 dB linewidth of 0.15 nm at the maximum output power of 380 W. To efficiently and stably couple several-hundred-watt pump power into the hollow core and seal the gas, a hollow-core fiber end-cap is fabricated and used at the input end. A maximum power of 110 W at 1153 nm is obtained in a 5 m long hollow-core PCF filled with 36 bar H₂, and the conversion efficiency of the first Stokes power is around 48.9%. This work paves the way for high-power fiber gas Raman lasers.

Continuous operation of fiber gas Raman lasing at the 1135 nm wavelength is experimentally demonstrated with an output power exceeding 26 W. Rotational stimulated Raman scattering (Rot-SRS) is generated in the hydrogen gas filled 50 m homemade anti-resonant hollow-core fiber (AR-HCF). A single-frequency fiber laser at the 1064 nm wavelength is used as the pump source, and a minimum threshold of 31.5 W is measured where the core diameter of AR-HCF reaches 37 µm. Up to 40.4% power conversion efficiency of forward Rot-SRS is achieved in the single-pass configuration, corresponding to a quantum efficiency of 43.1%. Over 1 W strong backward Rot-SRS is observed in the experiment, ultimately limiting the further increase of Rot-SRS generation in the forward direction.

Direct current pulsed discharge is a promising route for producing high-density metastable particles required for optically pumped rare gas lasers (OPRGLs). Such metastable densities are easily realized in small discharge volumes at near atmospheric pressures, but problems appear when one is trying to achieve a large volume of plasma for high-power output. In this work, we examined the volume scalability of high-density metastable argon atoms by segmented discharge configuration. Two discharge zones attached with peaking capacitors were connected parallelly by thin wires, through which the peaking capacitors were charged and of which the inductance functioned as ballasting impendence to prevent discharging in only one zone. A uniform and dense plasma with the peak value of the number densities of Ar (1s⁵) on the order of 1013cm-3 was readily achieved. The results demonstrated the feasibility of using segmented discharge for OPRGL development.

半导体泵浦亚稳态惰性原子激光是高能光泵浦气体激光领域具有潜力的新方案。已有报道均在约束的放电空间内产生亚稳态原子，功率放大受到多因素制约。为突破现有方案的局限，采用大气压等离子体射流方式在羽流区域产生高浓度亚稳态氩原子（10¹⁴ cm⁻³量级），将放电和激光区域空间分离，利用811 nm窄线宽半导体激光器作为泵浦源，基于泵浦、激光和气流相互垂直的结构实现912 nm激光输出，有效拓展了该型激光体系的功率定标放大能力。