More than 15 W CW, 10 MHz linewidth laser at 589 nm using Raman fiber amplifier

We have focused on Raman fiber lasers. However, the early onset of stimulated Brillouin scattering (SBS) has previously thwarted their successful operation at narrow bandwidths and high power. We use a MOPA scheme, in which an 1178 nm fiber coupled DFB diode seeds an 1120 nm pumped Raman fiber amplifier. Both seed and pump fiber lasers are commercially available. We have found a way to sufficiently limit SBS effects and achieve narrow-band Raman amplification, with the linewidth limited so far only by the seed linewidth. To our knowledge it is the highest power obtained at such a narrow linewidth with Raman fiber amplifiers.