一种新型光纤光栅传感器解调系统

Design of a New Style of Fiber Bragg Grating Demodulation System

选择线性滤波法解调光纤光栅(FBG)传感信号,实现传感光栅Bragg波长微小偏移的实时检测。利用单片机取代PC机,有效实现了系统的小型化。采用锁相放大电路和24位∑-Δ高精度A/D转换模块采集有用信号,提高系统精度和动态范围。使用USB接口模块存储和传输数据,使解调系统特别适合现场测量和野外作业的要求。设计出了一种新型FBG传感器解调系统,通过实验和数据验证了该系统高精度、便携带的特点。

The linear filter demodulation method is used by wavelength division multiplex（WDM） to realize the real-time detection. MCU is used as the main control module instead of PC to miniaturize and simplify the demodulation system. A lockin amplifier detecting circuit and an ∑-△ A/DC are used to improve the SNR and the dynamic range of the system. USB interface circuit is used to facilitate the data transmission and stroage which makes the system especially suitable for filedwork. So the demodulation system of fiber Bragg grating sensor has the outstanding features of simple structure, low cost, easy operation and portability. The experimental results demonstrate the sensitivity and portability of the demodulation mechanism.