Sub-nanosecond stimulated Brillouin scattering pulse compression using HT270 for kHz repetition rate operation

Abstract

With mitigation of thermal effects in a generator cell based on a rotating off-centered lens, the effects of thermal blooming, self-defocusing, and thermal convection in the amplifier cell have experimentally proven to be the main factors limiting high-repetition-rate stimulated Brillouin scattering (SBS) pulse compression. To alleviate these effects, Galden HT270, which has a large viscosity coefficient, is used and compared experimentally. The operating repetition rate using HT270 was improved from 200 Hz to 1,000 Hz, comparable to the values in the literature. With a pump energy of 50 mJ at 1,000 Hz, the pump pulse was compressed down to 820 ps using HT270 with an energy efficiency of 52.2%. If the injection energy is further increased, the SBS energy efficiency can be increased beyond this value. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement