An Elimination Method of Polarization-Induced Phase Shift and Fading in Dual Mach–Zehnder Interferometry Disturbance Sensing System

Intelligent intrusion detection for optical fiber perimeter security system based on an improved high efficiency feature extraction technique

“…As n, L, c are all known, thus according to the equation ( 3), the position x of the external intrusion event can be determined once the time delay τ is demodulated. By removing the DC components, the AC components can be compensated through polarization control-related measures [6]. Thus, the equation ( 2) can be simplified as:…”

“…And these sensors have the capability to simultaneously monitor up to hundreds of independent sensors over a single fiber link based on its specific spatial resolution. Among these sensors, the dual Mach-Zehnder interferometer (DMZI)-based optical fiber distributed vibration sensing technology is received increasing attention from researchers and engineers in the past decades [6,7]. The DMZI-based sensing technology can realize vibration detection over a single fiber through the use of phase modulation strategy.…”

Ultra-long-range modulated asymmetric vibration sensor based on high-frequency carrier

“…Distributed vibration sensor based on dual Mach-Zehnder interferometer (DMZI) have been successfully applied in many fields such as oil and gas pipeline security monitoring, railroad health monitoring, perimeter security and so on [1,2]. The mainstream method of estimating the time delay between two signals propagating in the forward and reverse directions is usually based on cross-correlation algorithm, whose accuracy is closely related to the bandwidth and similarity of the signals.…”