Numerical model of stimulated Brillouin scattering excited by a multiline pump

Stimulated Brillouin Scattering Phase Conjugate Mirror and its Application to Coherent Beam Combined Laser System Producing a High Energy, High Power, High Beam Quality, and High Repetition Rate Output

“…Furthermore, if the pump laser mode spacing exceeds the Brillouin linewidth (Ω m >Г), regardless of the mode structure, the SBS gain is the same as that of a single longitudinal mode pump (Narum et al, 1986). Moreover, even if Ω m < Г, the offresonant acoustic waves, which are generated by the beating between the pump laser mode and another Stokes mode, play an important role in enhancing the gain and the reflectivity (Mullen et al, 1987;Bullock et al, 1994). In all the previously mentioned works, however, the influence of the multimode pump was considered only for two or several longitudinal modes and low pump energy near the SBS threshold.…”