High power fiber lasers in the SWIR band using Raman lasers

Identifying the scope for high power laser sources around 1.6 μm band in LIDAR and free space optical communication applications, because of high atmospheric transparency in this band, we have built a high power laser that generates >25 W of output power at 1570 nm using sixth-order cascaded Raman amplification of a low power, Erbium–Ytterbium seed. A high power Ytterbium doped fiber laser operating at 1117 nm generating >100 W CW output power was built and used as the primary laser source for Raman laser experiments. We also demonstrated a novel, drive scheme for standard laser diode modules (without wavelength locking) used for pumping rare-earth doped lasers and amplifiers. This scheme improves the pumping efficiency and reliability of the laser without increasing nonlinearity in a cost effective manner.