基于气压控制的单谱线4.3μm空芯光纤HBr激光器

Hollow-Core Fiber HBr Laser with 4.3 μm Single Spectral Line Based on Gas Pressure Control

基于空芯光纤(HCF)的气体激光器是实现中红外激光输出的一种有效手段,一般情况下,跃迁选择定则决定一条泵浦吸收谱线对应两条激射跃迁谱线。通过气压控制的方法实现了单一谱线的4.3μm单程结构HCF HBr激光器。以自研的1958 nm连续波高功率窄线宽掺铥光纤放大器为泵浦源,泵浦一段5 m长、充低压HBr气体的反共振HCF,通过气压控制分别实现了同位素H;Br和H;Br单一谱线4.3μm的激光输出,最大激光功率为350 mW,总的光光转换效率约为8%。利用自行搭建的光纤扫描装置测量了输出激光光斑,结果表明其是一种基模。

Gas laser based on hollow-core fiber(HCF) is an effective means to realize mid-infrared laser output. Generally, according to the transition selection rule, one pump absorption line corresponds to two lasing transition lines. A single-pass HCF HBr laser with a 4.3 μm single spectral line is realized by means of air pressure control. Using the self-developed 1958 nm continuous wave high-power narrow linewidth thulium-doped fiber amplifier as the pump source, a 5-meter-long anti-resonant HCF filled with low-pressure HBr gas is pumped. The laser output with 4.3 μm single spectral line of isotope H;Br and H;Br is realized respectively through air pressure control, the maximum laser power is 350 mW, and the total optical-optical conversion efficiency is about 8%. The output laser spot is measured by the self-built optical fiber scanning device, and the result shows that it is a fundamental mode.