Combination of phase modulation and coding for SNR enhancement in distributed Brillouin sensors

This reported work proposes and demonstrates the benefits of a phase-coded pump using Simplex code into a distributed strain sensor based on Brillouin optical-fibre time-domain analysis technique. It is considered that the experimental results show significant signal-to-noise ratio (SNR) enhancement provided by an increasing length of the phase-coded pump with short code length (7 to 31 bits), thus allowing for strain sensing over a 30 m standard fibre with 1 cm spatial resolution.