基于复合干涉的光纤低相干干涉传感系统研究

研究一种能够进行远程及绝对测量的光纤低相干干涉传感系统。该系统包含两个光纤干涉仪,其中一个光纤干涉仪置于被测场中感应被测量的变化,可实现远程测量;另一个光纤干涉仪解调被测量的值。运用波分复用技术,使用于解调的光纤干涉仪同时工作于低相干干涉和高相干干涉状态。用低相干干涉信号决定被测量的幅值,对被测量实现绝对测量,并使测量量程不受波长限制;同时,用高相干干涉信号对被测量进行高精度的测量。系统的测量量程为6mm,测量分辨率小于1nm,位移实验结果的线性相关系数R为0.99。

Research on an Optical-Fiber Low-Coherence Interferometric Sensing System Based on Multiplexing Interferometric Technology

An optical-fiber low-coherence interferometric sensing system, which is suitable for distance and absolute measurement, is presented. The system includes two optical fiber inteferometers. One of the optical fiber interferometer is embedded in the measured field for sensing the measurand and absolute measurement can be realized. The measurement range is never limited by the optical wavelength. And the other optical fiber interferometer is for demodulating the measurand. Based on wavelength-division-multiplexing technology, the demodulating optical fiber interferometer works in both modes of low-coherence interferometry and high-coherence interferometry. The signal of low-coherence interferometry is for determining the amplitude of the measurand, and the signal of high-coherence interferometry is for measuring the measurand precisely. The measurement range is 6 mm and the resolution is less than 1 nm. The linear correlation coefficient of the displacement measurement is 0.99.