Fluoride glass Raman fiber laser at 2185 nm

We report on the first Raman laser based on a fluoride glass optical fiber. The Raman fiber laser was pumped by a 9.6W Tm(3+) :silica CW fiber laser operating at a wavelength of 1940nm. A maximum output power of 580mW was measured at 2185.1 nm, corresponding to a frequency shift of 579cm(-1) (17.37 THz). We observed a threshold power of 3.8W and a low power slope efficiency of 29% with respect to the launched pump power. Using those results and the known fiber parameters, we estimated a Raman gain peak value of 3.52 * 10(-1)4 m/W, which is lower than the previously reported values. (C) 2011 Optical Society of America