title: 25 W Raman-fiber-amplifier-based 589 nm laser for laser guide star.
abstract: We report on a 25 W continuous wave narrow linewidth (< 2.3 MHz) 589 nm laser by efficient (> 95%) coherent beam combination of two narrow linewidth (< 1.5 MHz) Raman fiber amplifiers with a Mach-Zehnder interferometer scheme and frequency doubling in an external resonant cavity with an efficiency of 86%. The results demonstrate the narrow linewidth Raman fiber amplifier technology as a promising solution for developing laser for sodium laser guide star adaptive optics.
authors.affiliation: European Southern Observatory, Karl-Schwarzschildstr 2, D-85748 Garching, Germany. yfeng@eso.org
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Luke R
authors.initials: LR
authors.lastname: Taylor
authors.forename: Domenico Bonaccini
authors.initials: DB
authors.lastname: Calia