EFFICIENT TEMPORAL COMPRESSION OF COHERENT NANOSECOND PULSES IN COMPACT SBS GENERATOR-AMPLIFIER SETUP

A pulse compressor based on stimulated Brillouin scattering (SBS) in l iquids is experimentally and theoretically investigated, It allows for the compression of Fourier-transform Limited nanosecond pulses of sev eral hundreds of millijoules of energy with both high conversion effic iency and a high temporal compression factor. The two-cell generator-a mplifier arrangement is of a compact design not requiring external att enuation of the generator cell input energy, Pulses from an injection- seeded, frequency-doubled Nd:YAG laser of 300-mJ energy were compresse d by a factor variable between 6 and 21 at up to 75% reflectivity, Dev iation from unity SBS reflectivity is predominantly determined by opti cal component losses, The generation of 270-ps pulses with high beam q uality was achieved in liquid methanol, These powerful pulses of varia ble duration are difficult to produce with common laser systems and ar e highly suited for the generation of high-harmonics in gases.