Phase-sensitive optical time domain reflectometer type optical fiber distributed disturbing sensor of double-arm pulse optical interference

Abstract

The invention relates to the technical field of the optical fiber sensor, providing a phase-sensitive optical time domain reflectometer type optical fiber distributed disturbing sensor of double-arm pulse optical interference. By adopting a laser that is narrow in line width, large in power and low in frequency drift, the phase-sensitive optical time domain reflectometer type optical fiber distributed disturbing sensor of double-arm pulse optical interference provided by the invention based on the phase-sensitive optical time domain reflection technology can position the disturbing signals in a single point or multiple points simultaneously through interference of backward Rayleigh scattering light in two sensing arms pulse width areas by comparing the signals after and before disturbance. By extracting the phase information in a trigonometric function for large numbers accumulation or average, the invention improves the sensitivity of the system equivalently. The invention improves the sensitivity of the system by way of square or exponentiation. Finally, optimally, PGC (phase generated carrier) algorithm is used to extract the phase information so as to eliminate the influence of random change of scattered signals, thereby improving the sensitivity of the system equivalently.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensors, in particular to a phase-sensitive optical time-domain reflectometer type optical fiber distributed disturbance sensor with double-arm pulsed light interference. Background technique [0002] Due to its high sensitivity, small size, light weight, intrinsic safety, electrical insulation, anti-electromagnetic interference, relatively low cost, versatility, high reliability, hardware matching optical fiber communication interface, easy networking, especially can realize Excellent features such as distributed measurement have a wide range of applications in industrial, civil and military fields. Among them, the optical fiber distributed disturbance sensor is of great significance in the fields of perimeter security, oil and gas pipeline monitoring, large structure monitoring and communication line monitoring. [0003] The fiber optic distributed disturbance sensor can monitor the distu...

AI Technical Summary

Problems solved by technology

[0017] Aiming at the shortcomings of the prior art, in order to solve the problem of poor performance of various optical fiber sensors in the prior art in long-distance applications, the present invention proposes a phase-sensitive optical time-domain reflectometer-type optical fiber distribution with dual-arm pulsed light interference. The disturbance sensor uses scattered signals for disturbance detection, which can realize multi-point disturbance positioning at the same time, which improves the detection sensitivity and solves the problem of positioning error or positioning failure caused by scattering in long-distance applications.

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