Powerful linearly-polarized high-order random fiber laser pumped by broadband amplified spontaneous emission source.

A great deal of attention has been drawn to Random fiber lasers (RFLs) for their typical features of modeless, cavity-less and low coherence length. However, most previously reported high power RFLs employ narrowband fiber lasers as the pump source, thus inducing the self-pulsing transferring from pump source to output Stokes. In this contribution, linearly-polarized RFL pumped by broadband amplified-spontaneous-emission (ASE) is demonstrated and continuous-wave (CW) high order Stokes can be obtained.With 30.6 W pump injected into the half-opened cavity, 23.51 W the 2 order Stokes centered at 1178 nm with a full width at half-maximum linewidth of 1.73 nm and polarization extinction ratio of about 25 dB can be obtained. The standard deviation and peak-vale value of the 2 order Stokes light at maximal output power is just 0.47% and 4.10%, which indicates the good power stability. Significantly, the corresponding quantum efficiency of the 1 and 2 order Stokes light is about 87% and 85%, and almost all pump photons are converted into Stokes photons. As far as we know, it is the highest power ever reported from linearly polarized RFL, and further power scaling is available in the case of more powerful pump source and optimization of system parameters.