Comparison of Self-Seeded Perfluorooctane SBS-Compressor Configurations for Obtaining High-Energy 90 ps Pulses

Pulse compression based on stimulated Brillouin scattering (SBS) in counterpropagating ns pump pulses [1] makes it possible to achieve a pulse width of
$\sim 110$
ps in liquids such as perfluorooctane
$\mathrm{C}_{8}\mathrm{F}_{18}$
[2] and carbon tetrachloride
$\text{CC}1_{4}$
[3], as well as
$\sim 180$
ps in fused quartz [4]. The most studied
$\text{CC}1_{4}$
is toxic for use in medical lasers, is not suitable for phase conjugation in two-pass amplifiers as it is prone to optical breakdown and has a low reflectivity
$\sim$
40% of the SBS-mirror. In contrast, the safety of
$\mathrm{C}_{8}\mathrm{F}_{18}$
has been proven by its use as a coolant, tamponade in eye surgery and even as a breathable fluid. The high breakdown threshold and reflectance above 90% allow it to be used in high-energy
$> 200\text{mJ}$
two-pass phase-conjugated amplifiers [2]. Self-seeding of the SBS-compressor with
$\text{CC}1_{4}$
allows to improve energy stability, reduce jitter, and achieve shorter pulses [3], albeit with an energy limited to
$\sim 1\text{mJ}$
. The goal of this study was to compare different designs of self-seeded SBS-compressors with
$\mathrm{C}_{8}\mathrm{F}_{18}$
to ensure
$\sim 90$
ps high-energy pulses with a smooth beam suitable for laser dermatology.