High-power linearly-polarized tunable Raman fiber laser

In this study, we demonstrate an all-fiber high-power linearly-polarized tunable Raman fiber laser system. An in-house high-power tunable fiber laser was employed as the pump source. A fiber loop mirror (FLM) serving as a high reflectivity mirror and a flat-cut endface serving as an output coupler were adopted to provide broadband feedback. A piece of 59-m commercial passive fiber was used as the Raman gain medium. The Raman laser had a 27.6 nm tuning range from 1112 nm to 1139.6 nm and a maximum output power of 125.3 W, which corresponds to a conversion efficiency of 79.4%. The polarization extinction ratio (PER) at all operational wavelengths was measured to be over 21 dB. To the best of our knowledge, this is the first report on a hundred-watt level linearly-polarized tunable Raman fiber laser.