Nd : YAG laser with a stimulated Brillouin scattering mirror and variable pulse duration

Different ways of varying the output pulse duration in laser schemes compri sing a powerful master oscillator, a multipass amplifier, and a stimulated Brillouin scattering (SBS) mirror are suggested and realized experimentally . Conditions are determined at which introduction of losses between a SBS m irror and an amplifier allow variation of the output pulse duration without any significant decrease in energy. The use of two different SBS media (Sn Cl4 and freon) allows construction of a laser where the output pulse durati on is varied between 6 and 40 ns and the energy loss is no more than 30%. ( C) 2000 Society of Photo-Optical Instrumentation Engineers.