干涉型光纤海洋参数传感器的分布式测量方法研究

Research on the Distributed Measurement Method of Ocean Optical Fiber Sensor Based on Interferometer

光纤传感器因其灵敏度高、体积小等优点在海洋监测领域得到了广泛关注.目前高性能的海洋温盐深参数监测光纤传感器大都基于干涉原理,难以实现同一系统内多个传感器的复用,不能满足海洋环境参数高时空分辨力的监测需求.基于调频连续波原理,提出一种适用于干涉型海洋参数光纤传感器的大容量复用方法.利用不同干涉仪端面反射光与参考光形成Mach-Zehnder干涉光谱的特征频率确定不同传感器的位置,通过不同端面特征频率间的拍频还原了单个传感器的光谱.设计并搭建了干涉型海洋参数传感器的分布式传感系统,实现了系统中传感器的定位以及光谱信号还原,并通过理论计算证明分布式传感系统中至少可以实现500个传感器的复用.本论文的研究可以为高性能干涉型光纤传感器的海洋参数链式监测提供技术支持.

Optical fiber sensor has attracted a lot of focus in the ocean observation domain for its high sensitivity and small volume.Currently,the high performance optical fiber sensor is mainly dominated by sensors based on the interference principle.It is hard to achieve the multiplexing with a large number of sensors,which cannot meet the monitoring requirement of high spatiotemporal resolution of ocean parameters.In this paper,a large capacity multiplexing technology based on frequency modulation continuous wave for interferometric optical fiber sensors is proposed.The Mach-Zehnder interferometer formed by the reference beam and reflected light is used to locate the position of the sensor,and the beat frequency between two reflective mirrors is employed to recover the spectrum of the sensor.The distributed sensing system for interferometric optical fiber sensors is designed and built,and the positioning and distinction spectral signals of sensors are realized.The theoretical calculation result indicates the multiplexing amount of sensors can reach 500 at least.The research work in this paper paves the way for the chain monitoring of ocean parameters based on high performance interferometric optical fiber sensors.