Phase-Sensitive Optical Time Domain Reflectometry With Rayleigh Enhanced Optical Fiber

In this paper, a phase-sensitive optical time domain reflectometry ( Φ-OTDR) based on Rayleigh enhanced optical fiber is proposed to improve the system signal-to-noise ratio (SNR). In the experiment, the vibration performance of the Rayleigh enhanced optical fiber is analyzed and compared with standard single-mode telecom fiber. The results demonstrate that the measured SNRs of peaks in frequency spectra have been improved by 14 dB (at 1 kHz vibration frequency) at the end of the 2 km specialty sensing fiber. A wide range of vibration frequencies from 50 Hz to 15 kHz are demonstrated experimentally. The proposed method overcomes the inherent limitations of the conventional Φ-OTDR system and significantly enhances the vibration sensing performance.