Chaotic Brillouin Optical Correlation-Domain Analysis Based on Differential Correlation Demodulation

We propose and experimentally demonstrate a chaotic Brillouin optical correlation-domain analysis (BOCDA) based on a differential correlation demodulation configuration. Multiple correlation peak (CP) localization is achieved by the gain of the central CP (CCP) and that of the difficult-to-eliminate time-delay signature (TDS) peak. The probe differential scheme is introduced and simulated to eliminate the influence of power superposition and obtain the optimized gain distribution. On this basis, the gain interval extraction method is proposed to separate the gain of CCP and TDS positions, and the corresponding Brillouin gain spectra are obtained in simulation and experiment. Ultimately, the synchronous localization of the CCP and TDS with a sensing distance of 410 m and a spatial resolution of less than 8 cm is experimentally demonstrated.