Stimulated Brillouin Scattering Thresholds in Optical Fibers for Lasers Linewidth Broadened with Noise

TL;DR

This paper investigates how noise-based linewidth broadening techniques affect the stimulated Brillouin scattering threshold in optical fibers, emphasizing the importance of length-dependent corrections especially for short fibers used in high-power applications.

Contribution

It introduces length-dependent corrections to SBS threshold calculations when using noise-based linewidth broadening, highlighting their significance for short fiber lengths.

Findings

Noise broadening effects are length-dependent.

Short fiber lengths require correction factors for SBS threshold.

Noise-induced broadening can be less effective than expected without corrections.

Abstract

Phase and/or intensity modulation techniques to broaden the Linewidth of an optical source are well known methods to suppress stimulated Brillouin scattering (SBS) in optical fibers. A common technique used to achieve significant bandwidth enhancement in a simple fashion is to phase modulate with a filtered noise source. We will demonstrate here that, in this case the stochastic nature of noise requires an inclusion of length dependent corrections to the SBS threshold enhancement. This effect becomes particularly significant for short fiber lengths common to most high power fiber amplifiers.