Manuel Rodolfo Martínez, Shlyagin M G, Miridonov S V
Optics Department, CICESEKm. 107 carretera Tijuana a Ensenada, Ensenada, Baja California, 22860 México.
Opt Express. 2008 Dec 8;16(25):20666-75. doi: 10.1364/oe.16.020666.
A novel technique for distributed detection and localization of vibrational disturbances is presented. It is based on a serial array of identical low-finesse Fabry-Perot interferometers interrogated at a fixed wavelength by DFB diode laser intensity modulated at 10 KHz. Interferometers are formed directly in the single mode SMF-28 fiber by pairs of fiber Bragg gratings with reflectivity < 0.05% each. A simple signal processing based on the Fourier transform of detected signals and evaluation of phases for different signal components enables localization of a perturbed interferometer with a high accuracy. In experiment, a localization accuracy of 10 meters has been demonstrated for 5 km long fiber after 1 s of averaging. The system has the capability of using well in excess of 100 interferometers in a single fiber channel. A simple sensor configuration and the use of low-frequency components make it potentially inexpensive and suitable for applications where a continuous monitoring of long structures has to be performed for appearance of vibrations.
本文提出了一种用于振动干扰分布式检测与定位的新技术。该技术基于一系列相同的低精细度法布里-珀罗干涉仪，由10 kHz强度调制的分布反馈（DFB）二极管激光器在固定波长下对其进行询问。干涉仪直接在单模SMF-28光纤中由成对的光纤布拉格光栅形成，每个光栅的反射率<0.05%。基于检测信号的傅里叶变换以及对不同信号分量相位的评估进行简单的信号处理，能够高精度地定位受干扰的干涉仪。在实验中，经过1秒的平均后，对于5公里长的光纤，已证明定位精度为10米。该系统能够在单个光纤通道中使用超过100个干涉仪。简单的传感器配置以及低频分量的使用使其可能成本低廉，适用于必须对长结构进行连续监测以检测振动出现的应用场景。
