title: Theoretical analysis of single-frequency Raman fiber amplifier system operating at 1178 nm.
abstract: We analyze the scalability of amplifying the output from a single-frequency diode laser operating at 1178 nm through the utilization of a core pumped Raman fiber amplifier. A detailed model that accounts for stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in relation to the fiber mode field diameter, length, seed power, and available pump power in both co-pumped and counter-pumped configurations is developed. The backward travelling Stokes light is initiated from both spontaneous Brillouin and spontaneous Raman processes. It is found that when fiber length is optimized, the amplifier output scales linearly with available pump power. Although higher amplifier efficiency is obtained with higher seed power, the output power diminishes. In order to mitigate the SBS process for further power scaling, we employ and optimize a multi-step temperature distribution. Finally, we consider the feasibility of generating the D(2a) and D(2b) lines in a sodium guide star beacon from a single Raman amplifier by examining four-wave mixing (FWM).
authors.affiliation: Advanced Electric Lasers Branch, Air Force Research Laboratory, Kirtland Air Force Base, New Mexico 87117, USA. chris.vergien@gmail.com
authors.forename: Christopher
authors.initials: C
authors.lastname: Vergien
authors.forename: Iyad
authors.initials: I
authors.lastname: Dajani
authors.forename: Clint
authors.initials: C
authors.lastname: Zeringue
mesh_terms: D000669:Amplifiers, Electronic; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D008962:Models, Theoretical; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*