Improving the SNR of the phase-OTDR by controlling the carrier in the SOA. Issue 14 (15th August 2020) - Chen, Yun
Abstract : Semiconductor optical amplifier (SOA) is a common choice for pulse generator of a homodyne phase-OTDR (phase-sensitive optical time-domain reflectometry) system. A forced carrier recombination method is proposed for improving the extinction ratio (ER) of an SOA. The input laser-excited carriers in the SOA can reduce its ER. The proposed method eventually improves the signal-to-noise ratio (SNR) of the phase-OTDR. The effect of ER improvement is analysed by using the rate equation model, and in the experiment the SNR is improved by 5.2 dB in the phase-OTDR system: this result is important for long distance distributed vibration sensing application.