High-repetition-rate, quarter acoustic wave oscillation period pulse compression using transient stimulated Brillouin scattering

In this work we demonstrate the compression of laser pulses at a high repetition rate, using transient stimulated Brillouin scattering (SBS). Output pulses with pulse durations close to the quarter-acoustic wave oscillation period (τf) was obtained. We find that the primary factors which limit the compression of pulses under high repetition-rate, transient conditions are the inherently low gain in the transient regime, thermal accumulation within the SBS medium and optical breakdown. We show that short phonon lifetimes can suppress the trailing edge amplification of the output pulse, while also reducing the threshold and improve energy efficiency. In this work, we demonstrate the generation of output laser pulses with a repetition-rate of 200 Hz and an average pulse duration of 1.08τf using the electronic-fluorinated liquid FC-43. Due to the fast decay of the acoustic field, compressed pulses with duration <τf were also observed. We also demonstrate efficient output of pulses with repetition-rate of 200 Hz and energy efficiency of up to 40% using the heat transfer fluid HT-230.