报道了第一个连续波全光纤气体拉曼激光光源。采用实芯单模光纤与带隙型空芯光纤熔接的方法,制备了长度为50 m、充高压氢气的全光纤结构气体腔,以一个高功率连续波1540 nm光纤放大器为泵浦源,利用氢气分子的纯转动受激拉曼散射有效实现了1693 nm 斯托克斯连续激光输出。进一步,通过在气体腔输出端熔接一个中心波长为1540 nm的高反射率光纤布拉格光栅,使得拉曼阈值降低了38.2%,斯托克斯光输出功率最大为2.15 W,腔内拉曼转换效率为72.2%,由于熔接损耗,相对总泵浦光功率的光光转换效率为31.7%。该研究结果为实现高效紧凑的高功率1.7 μm 光纤激光器提供了一条可行的技术方案。

We report the first continuous-wave (CW) all-fiber gas Raman laser source. An all-fiber gas cavity with a length of 50 m and filled with high-pressure hydrogen was formed by fusion-splicing solid-core single-mode fiber and photonic band gap hollow-core fiber. A high-power CW 1540 nm fiber amplifier was used as the pump source, and efficient CW 1693 nm Stokes laser was obtained by pure rotational stimulated Raman scattering of hydrogen. Furthermore, by adding a high-reflection fiber Bragg grating with a center wavelength of 1540 nm at the output end of the all-fiber gas cell, the Raman threshold is reduced by 38.2%, the maximum output Stokes power is 2.15 W, and the Raman conversion efficiency inside the gas cell is 72.2%, while the optical-to-optical conversion efficiency in terms of the total pump power is 31.7% due to the relatively high splicing loss. This work provides a feasible way for compact, high-efficiency, and high-power 1.7 μm fiber laser.