A high Brillouin amplification using liquid fluorocarbon

Although the gain coefficient of the Stimulated Brillouin Scattering (SBS) of the fluorocarbon liquid C8F18 is substantially lower than for other nonlinear media, it is an attractive medium since its highly purified version has a high optical breakdown threshold, and it is stable and very safe to operate. We have utilized it as a phase conjugate mirror (PCM) and the PCM reflectivity better than 90% has been achieved at optimized focusing conditions of an incoming beam. The output energy of the phase conjugated pulse linearly followed the input pulse energy after reaching the threshold level at about 3.3 mJ. The slope efficiency was estimated about 95% without taking into account components' losses. Brillouin amplification through SBS has been realized in highly purified fluorocarbon liquid C8F18. This report discusses the design and results of performed experimental studies of the SBS in C8F18 demonstrating the amplification of a week signal beam (37 nJ) reaching up to 105 or 50 dB.