Bandwidth effects in stimulated Brillouin scattering driven by partially incoherent light

TL;DR

This paper develops a generalized statistical theory to analyze how bandwidth influences stimulated Brillouin scattering, revealing that increasing bandwidth can significantly reduce the instability growth rate.

Contribution

It introduces a comprehensive dispersion relation for SBS driven by broadband light with arbitrary statistics, extending the classic monochromatic theory.

Findings

Growth rate of SBS can be reduced by 1/3 with a 0.3 nm bandwidth

Generalized dispersion relation applicable to broadband radiation

Monochromatic limit recovered from the generalized theory

Abstract

A generalized Wigner-Moyal statistical theory of radiation is used to obtain a general dispersion relation for Stimulated Brillouin Scattering (SBS) driven by a broadband radiation field with arbitrary statistics. The monochromatic limit is recovered from our general result, reproducing the classic monochromatic dispersion relation. The behavior of the growth rate of the instability as a simultaneous function of the bandwidth of the pump wave, the intensity of the incident field and the wave number of the scattered wave is further explored by numerically solving the dispersion relation. Our results show that the growth rate of SBS can be reduced by 1/3 for a bandwidth of 0.3 nm, for typical experimental parameters.