Passive Q-switching in all-fibre Raman laser with distributed Rayleigh feedback

Abstract
The experimental demonstration of the all-fibre passive Q-switching operation of a Raman fibre laser is reported. Giant pulses around 1550 nm with a peak power of 1 kW and pulse duration down to 1 ns were obtained with a 10 km-long fibre cavity pumped by a 2.4 W continuous-wave fibre laser source. Reported experimental data indicate that Rayleigh, Brillouin and Raman scatterings are all involved in the pulse generation process.