Numerical Simulation of Noise in Pulsed Brillouin Scattering

TL;DR

This paper introduces a versatile numerical method for simulating noise in pulsed Stimulated Brillouin Scattering, accounting for thermal and phase noise, and analyzing their effects on optical and acoustic power in various scenarios.

Contribution

The paper presents a new numerical model for noise in pulsed SBS that applies to arbitrary geometries and includes thermal and laser phase noise effects.

Findings

Thermal noise significantly influences field statistics.

Laser phase noise affects SBS when coherence time is comparable to pulse duration.

The method enables versatile noise simulations for various waveguide configurations.

Abstract

We present a numerical method for modelling noise in Stimulated Brillouin Scattering (SBS). The model applies to dynamic cases such as optical pulses, and accounts for both thermal noise and phase noise from the input lasers. Using this model, we compute the statistical properties of the optical and acoustic power in the pulsed spontaneous and stimulated Brillouin cases, and investigate the effects of gain and pulse width on noise levels. We find that thermal noise plays an important role in the statistical properties of the fields, and that laser phase noise impacts the SBS interaction when the laser coherence time is close to the time-scale of the optical pulses. This algorithm is applicable to arbitrary waveguide geometries and material properties, and thus presents a versatile way of performing noise-based SBS numerical simulations, which are important in signal processing, sensing, microwave photonics and opto-acoustic memory storage.