Efficient inhibition of Rayleigh scattering in interferometric sensor through random phase noise

Rayleigh scattering is the main restrictive factor for the long-distance fiber sensing especially in fiber optic interferometric sensor with uplink and downlink transmission shared common leading fiber. Here, the interrogation pulses are modulated by binary phase - shift keying (BPSK) to inhibit the Rayleigh scattering, and the binary sequence is generated from random noise. Experimental results show that with the modulation of noise sequence, the background noise of 10 km sensing system resulted from Rayleigh scattering is inhibited more than 20 dB. This report provides an economical and convenient method to solve the Rayleigh scattering without any devices in sensing end.