Short-pulse gain-switched Raman fiber laser based on conventional silica fibers

We report a high-energy 1666 nm short-pulse Raman fiber laser (RFL) based on gain-switching scheme. The RFL cavity is formed by conventional single mode fibers (SMFs), which is with low connection loss, low cost and ultrahigh compactness. To reduce the intra-cavity laser intensity and group velocity mismatch, the laser cavity and pump source parameters (i.e. laser output coupling, single-pass cavity length and pump pulse duration) are carefully selected to be 90%, 1 km and 10 ns, respectively. At last, an average output power of 670 mW, a single pulse energy of 223 nJ and a laser conversion efficiency of 66.9% have been successfully achieved. This work can clear a path towards high-performance and low cost 1666 nm fiber laser sources.