级联拉曼光纤激光器研究进展

Advances in cascaded Raman fiber lasers

稀土掺杂光纤激光器因受限于稀土元素的发射截面,只能在特定波长范围输出激光。理论上级联拉曼光纤激光器只要有合适的泵浦源和适当的谐振腔,即可输出任意波长斯托克斯光。以1064nm掺镱光纤激光器作泵浦源为例,以锗硅光纤为拉曼增益媒质,目前报道的级联拉曼光纤激光器输出的斯托克斯光波长范围为1120~2200nm。由于增益光纤具有很宽的拉曼增益谱,级联拉曼光纤激光器可进行宽带调谐,也可同时输出多个波长。级联拉曼光纤激光器不仅用于光通信上拉曼光纤放大器和远程泵浦掺铒光纤放大器的泵浦源,也可广泛用于超连续波产生、光传感、光成像等领域。对近几年来级联拉曼光纤激光器在理论设计基础、单、多波长级联拉曼光纤激光器等方面获得的取得的最新进展进行了概述。

Rare earth-doped fiber lasers can only generate radiations at limited wavelengths determined by the emission cross section of the doped element. Cascaded Raman fiber lasers (CRFL), however, can laser at any wavelength provided that the appropriate pump sources are available. An example of an ytterbium-doped fiber lasers acting as a pump and G2O5-doped fiber as Raman gain medium, cascaded Raman fiber lasers emitting at wavelengths within 1 120~2 200 nm have been reported. CRFL can be tunable over a large ran...