STIMULATED BRILLOUIN-SCATTERING IN SF6 WITH A FREE-RUNNING XECL LASERAS PUMP

XeCl laser system without dispersive elements is used to investigate n ear threshold reflectivity and phase-conjugation (PC) fidelity of stim ulated Brillouin scattering (SBS) mirrors with SF6 as the active mediu m. Using different focal-length lenses to focus the broadband laser ra diation into the Brillouin medium, it was found that at threshold the effective interaction length for SBS is equal to the confocal paramete r and that the SBS gain is equal to its steady-state value for monochr omatic pumping. High PC-fidelity values ranging from 0.8-1.0 were foun d under most of the experimental conditions investigated.