Kuroda Keiji
Department of Physics, School of Science, Kitasato University, Sagamihara 252-0373, Kanagawa, Japan.
Sensors (Basel). 2025 Jul 3;25(13):4158. doi: 10.3390/s25134158.
This article reports on the interrogation of fiber Bragg grating (FBG)-based sensors that are multiplexed in an asymmetric tree topology. At each stage in the topology, FBGs are connected at one output port of a 50:50 coupler with fibers of different lengths. This asymmetric structure allows the simultaneous interrogation of long-distance and parallel sensor networks to be realized. Time- and wavelength-division multiplexing techniques are used to multiplex the FBGs. Using the heterodyne detection technique, high-sensitivity detection of reflection signals that have been weakened by losses induced by a round-trip transmission through the couplers and long-distance propagation is performed. Quasi-distributed FBGs are interrogated simultaneously, over distances ranging from 15 m to 80 km.
本文报道了对基于光纤布拉格光栅（FBG）的传感器进行的研究，这些传感器以不对称树形拓扑结构进行复用。在拓扑结构的每个阶段，FBG连接到50:50耦合器的一个输出端口，并与不同长度的光纤相连。这种不对称结构使得能够同时实现对长距离和平行传感器网络的询问。采用时分复用和波分复用技术对FBG进行复用。利用外差检测技术，对经过耦合器往返传输和长距离传播所引起的损耗而减弱的反射信号进行高灵敏度检测。在15米至80公里的距离范围内，同时对准分布式FBG进行询问。
