高精度准分布式光纤光栅地震检波解调系统的研究

High-accuracy quasi-distributed optical fiber Bragg grating seismic demodulation system

提出了一种利用光纤超荧光光源的线性边带做边缘滤波器进行多点多参量实时测量的地震波信号解调系统.由于光源波长检测灵敏度对解调系统的灵敏度起决定作用,故对光源进行了优化设计,使得光源所用的线性段斜率得到了大幅度提高.所设计的解调系统以光源在吸收峰1530nm处的两段斜边将系统分为两个部分,各部分对应4个通道.通过对其中两个通道进行地震检波模拟测量,传感解调系统的两部分静态波长灵敏度分别为887.5mV/nm和-971.7mV/nm,应变分辨力分别达到了0.95με和0.86με.解调系统采用全光结构,解调灵敏度高,稳定性好,性价比高且反应速度快,可实现对地震信号的多点多参量实时检测.

A new earthquake detection demodulation system for monitoring several points and several parameters at the same time is proposed by using the linear sideband of super-fluorescent fiber source as an edge filter. The sensitivity of whole demodulation system is determined by the detecting sensitivity of source light. Through the optimization of light, the slope of light linear part is improved greatly. According to the rising and the falling of light, the system is divided into two parts each with four channels. Through the stimulation experiments of all the channels, the static wavelength sensitivities of the two parts are 887.5 mV/nm and -971.7 mV/nm, and their stain resolutions reseach 0. 95/z~ and 0.86/xe respectively. This demodulation system has high sensitivity, good stability, quick demodulation speed, etc. It is the most important is that it can realize real-time detection for several points and several parameters at the same time.