调频连续波分布式光纤布拉格光栅复用系统

Distributed fiber Bragg grating multiplexing system based on frequency modulation continuous wave

研究了利用调频连续波(FMCW)技术对分布式光纤布拉格光栅(FBG)复用系统进行寻址的基本原理;仿真分析了FBG传感器复用距离是系统最小分辨距离的整数倍或非整数倍时,对频谱信号的影响;搭建了基于FMCW的FBG复用系统实验平台,当传感距离1000m时,分别验证了不同扫描周期与复用系统差频信号的线性关系,及不同扫频范围与系统差频信号的线性关系。实验结果表明:FBG复用距离是系统最小分辨距离整数倍时,在测量距离1100 m范围内,系统测量最大误差为243 Hz,最大相对误差小于5%,可以实现FBG传感器的地址查询功能。

The principle of distributed fiber Bragg grating （FBG） addressing system based on frequency modulation contin- uous wave （FMCW） muhiplexing technology was studied. The influence of FBG multiplexing distance when it is an integer muhi- pie or a non-integer multiple of the minimum distance that the system is able to dislinguish on the signal spectrum was analyzed through the simulation experiment. An FBG muhiplexing experimental platform based on FMCW was established, when the sensing distance is 1000 m, we verify that the difference frequency signal keeps a linear relationship with the scanning cycle and the scanning range; when the FBG muhiplexing distance is an integer multiple of the minimum distance that the system is able to distinguish, within the measurement range of 1100 m, the maximum error of the system is 243 Hz, the maximum relative error is less than 5 %; thus FBG sensor addressing can be achieved.