title: Raman shifter optimized for lidar at a 1.5 microm wavelength.
abstract: A Raman shifter is optimized for generating high-energy laser pulses at a 1.54 microm wavelength. A forward-scattering design is described, including details of the multiple pass and nonfocused optical design, Stokes injection seeding, and internal gas recirculation. First-Stokes conversion efficiencies up to 43%--equivalent to 62% photon conversion efficiency--were measured. Experimental results show output average power in excess of 17.5 W, pulse energies of 350 mJ at 50 Hz, with good beam quality (M2<6). Narrow bandwidth and tunable output is produced when pumping with a single longitudinal mode Nd:YAG laser and seeding the process with a Stokes wavelength narrowband laser diode.
authors.affiliation: National Center for Atmospheric Research, Earth Observing Laboratory, P.O. Box 3000, Boulder, Colorado 80307-3000, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Spuler
authors.forename: Shane D
authors.initials: SD
authors.lastname: Mayor