鉴于单通道解调系统一次可检测的光栅波长数目有限, 同时为兼顾 FBG (光纤布拉格光栅)解调系统与上位机通信的稳定性与高速性, 结合波分复用与空分复用技术, 研制了多通道、多通信端口的FBG解调系统。通过控制16路光开关的光路切换, 可实现对16通道FBG传感网的空分复用, 对各通道传感器中心波长进行解调。测试结果表明, 解调系统中心波长分辨率为1 pm, 一次采集光栅波长信息的时间为620 ms, 16个光通道的FBG传感信息更新最短时间不大于10 s, 可对约200只光纤光栅传感器进行有效监测。

As a single-channel demodulation system can detect only a limited number (up to a dozen) of grating wavelengths a time and it is necessary to take into account the stability and high speed of both the Fiber Bragg Grating (FBG) demodulation system and host computer communications, a multi-channel, multi-communication-port FBG demodulation system is developed using the Wavelength Division Multiplexing (WDM) and Spatial Division Multiplexing (SDM) technologies. By controlling the lightpath switching of a 16-channel optical switch, the SDM of the 16-channel FBG sensing network and the demodulating of the center wavelength in each channel sensor can be realized. Test results show that the center wavelength resolution of the demodulation system is 1 pm and the time for collecting the granting wavelength information once is 620 ms, the minimum time for updating 16-channel FBG sensor information is not longer than 10 s. In addition, it is possible to effectively monitor about 200 fiber grating sensors.