Thermal suppression of high-repetition rate SBS pulse compression in liquid media

Thermal problems of high-repetition-rate stimulated Brillouin scattering (SBS) pulse compression in liquid media are theoretically and experimentally analyzed in detail. A wedge lens with less coma-aberration was designed using the ray tracing method and the thermally induced beam-pattern distortion was compensated by inhibiting thermal convection. The heat transfer form and fluid state were quantitatively analyzed for different SBS liquid media. For a 74-W pump power, 3-kHz pulse-compressed phase-conjugation mirror with an energy efficiency of 36.2% is achieved. A potential optimization method of continuously adjusting SBS output characteristics using a mixed medium is proposed and theoretically demonstrated, to improve energy efficiency.