Abstract

We report on a recent breakthrough in the generation of high power laser light at 589 nm that is needed for sodium laser guide stars and medical purposes. Large telescopes require 20–25W CW at 589 nm with good beam quality and linewidths of 50 MHz and below. Due to the virtual absence of useful solid state resonances at 589nm or 1178nm, and since laser guide star systems require high reliability and, optimally, small size, fiber lasers are an interesting option. 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.

© 2009 IEEE