Amplified-spontaneous-emission pumped raman fiber laser

We present an experimental study of a simple low-threshold Raman fiber laser, pumped by amplified spontaneous emission (ASE) of an erbium doped fiber amplifier. Such pumping for stimulated Raman scattering (SRS) and Raman laser, that is used to the best our best knowledge for the first time, suppresses stimulated Brillouin scattering and thus increases the pumping efficiency. The ASE pump had a central wavelength at 1550 nm and the outcome RFL oscillation wavelength was around 1670 nm, determined by the fiber Bragg gratings that formed the fiber resonator. We used various types of fibers, cavity lengths (2 - 25 km) and output grating reflectivities (4 - 97%). We obtained 34% overall laser to pump power efficiency and a pumping threshold power as low as ~160mW (as far as we know, the lowest ever achieved so far).