为了提高传感器的多路复用能力,基于低相干光纤传感技术,提出一种新型干涉仪组合拓扑结构.该结构由Michelson干涉仪的一个臂与若干个Mach-Zehnder干涉仪混合级联而成,构成了可以同时实现多传感器测量的传感网络.构建了实验系统,对传感特性进行了分析.实验结果表明:该拓扑结构可以实现一个解调干涉仪对网络系统中多个传感器的问询,可以实现应变和温度的测量.该系统中传感器的长度可自由选取,能用于大尺度结构形变的检测;也可以配对使用,并自动补偿应变测量过程中环境温度变化带来的影响.
In order to improve the multiplexing ability of optical sensors,based on the low interferential optic fiber sensing technology,a novel combination interferometer of Mach-Zehnder and Michelson system has been proposed and demonstrated.It consists of a Michelson interferometer and a series of tandem Mach-Zehnder interferometers which are linked with one arm of the Michelson interferometer,forming a multi-fiber optic sensors measuring network.It can be used to measure the distribution strain or temperature,especially suitable for monitoring large scale structural deformation due to its sensing gauge length could be chosen as long as tens of meters.It also could be used in the temperature compensation mode,in which one arm of the Mach-Zehnder interferometer measures strain caused by the variation of deformation and temperature,the other arm only measures the ambient temperature for eliminating the apparent strain caused by temperature.