Brillouin distributed temperature sensor employing phase modulation and optimization techniques

Abstract

The process of signal-to-noise ratio (SNR) improvement and the suppression of stimulated Brillouin scattering (SBS) effects on a long-range distributed sensor are presented in this paper. We have proposed an improved performance Brillouin distributed temperature sensor using phase modulation and optimization techniques. Global evolutionary computing-based optimization techniques (genetic algorithm (GA), particle swarm optimization (PSO) and differential evolution algorithm (DE)) are applied for both fiber and receiver optimization. The combination of phase modulation and the global evolutionary computing technique improved the SBS threshold power of the proposed system to an extent of 5.95dBm. However, with receiver and fiber optimization, for an input power of 0dBm, the proposed system provides SNR improvement up to 3.5dB, for temperature sensing over a distance of 50km with temperature resolution of 1.44K and spatial resolution of 32m without using filter. However, for the equivalent sensing range, we have achieved a temperature resolution as 0.51K using the above optimized system with filter.