A pulse compressor based on stimulated Brillouin scattering (SBS) in liquids is experimentally and theoretically investigated. It allows for the compression of Fourier-transform limited nanosecond pulses of several hundreds of millijoules of energy with both high conversion efficiency and a high temporal compression factor. The two-cell generator-amplifier arrangement is of a compact design not requiring external attenuation of the generator cell input energy. Pulses from an injection-seeded, frequency-doubled Nd:YAG laser of 300-mJ energy were compressed by a factor variable between 6 and 21 at up to 75% reflectivity. Deviation from unity SBS reflectivity is predominantly determined by optical component losses. The generation of 270-ps pulses with high beam quality was achieved in liquid methanol. These powerful pulses of variable duration are difficult to produce with common laser systems and are highly suited for the generation of high-harmonics in gases.

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Efficient temporal compression of coherent nanosecond pulses in a compact SBS generator-amplifier setup

An efficient two-cell stimulated Brillouin scattering (SBS) pulse-compressor design that can be scaled to large laser-pulse energies is described and a numerical model has been developed that accurately predicts the performance of this pulse-compressor system over a wide range of operating parameters. The compression of a 2.5 J input pulse from a width of 15.8 to 1.7 ns is experimentally demonstrated with 80 percent energy efficiency. A design of an SBS pulse compressor to compress a 25 J pulse to a pulse width less than 1 ns with 80 percent energy efficiency is presented. >

High-energy SBS pulse compression

A laser pulse temporal compression technique combining stimulated Brillouin scattering (SBS) and laser-induced breakdown (LIB) is proposed in which the leading edge of the laser pulse is compressed using SBS, and the low intensity trailing edge of the laser pulse is truncated by LIB. The feasibility of the proposed scheme is demonstrated by experiments in which a pulse duration of 8 ns is compressed to 170 ps. Higher compression ratios and higher efficiency are expected under optimal experimental conditions.

Pulse temporal compression by two-stage stimulated Brillouin scattering and laser-induced breakdown

Ultrashort pulse generation by phase locking of multiple stimulated Brillouin scattering

An approach that introducing a standing wave into focal area to stabilize the output energy and duration of stimulated Brillouin scattering (SBS) compression is presented. An interferometric scheme filled with FC-770 is used to improve the stability of both output energy and duration two times compared with an equivalent conventional SBS compressor. Moreover, the interferometric scheme shows a promotion for the performance of SBS compression.

A promotion of stability for temporal compression based on SBS in an interferometric scheme

Giant pulses (?l ? 30?50 nsec) from a ruby laser were shortened to 2.5?1.2 nsec by stimulated Brillouin scattering in a cell 1 m long filled with a liquid. In the case of CCl4 a reduction in the pulse duration by a factor of over 30 was achieved and the contrast of the Stokes pulses was found to be high.

K F Shipilov

Papers

Formation of highly compressed stimulated Brillouin scattering pulses in liquids

Synchronization of SMBS components in a laser cavity