Abstract

The benefits of optical-phase conjugation and coherent-beam combining can be conveniently-obtained by means of stimulated Brillouin scattering (SBS). However, several factors associate to make efficient generation of SBS more difficult at longer wavelengths. Phonon lifetimes increase as the square of the wavelength, and SBS power thresholds increase directly as the wavelength in the usual focused configuration. Thus longer pulse durations and higher laser powers are required. These in turn increase the likelihood of other effects such as optical breakdown and thermal heating through absorption, which can interfere with the SBS process. These considerations may explain why it is only relatively recently that SBS technology has been demonstrated^1–3 with hydrogen fluoride chemical lasers in the 3-μm spectral region.

© 1991 Optical Society of America