Presentation Information

[22p-12A-9]Tree Topology-FBG sensor based on heterodyne detection

〇Keiji Kuroda1, Kanta Yashiro1, Hisaki Oka1 (1.Kitasato Univ.)


Fiber Bragg grating,Heterodyne Detection,Tree Topology

FBG (Fiber Bragg grating) is actively used as a sensor head for temperature, strain sensing. To construct multiple sensing systems, it is a straightforward way to incorporate FBGs in a single fiber line in series. In addition, TDM(Time-division multiplexing) and WDM(Wavelength-division multiplexing) techniques are applied to increase the number of FBGs. However, if a trouble occurs in a point in such systems, FBGs beyond the point cannot be used. To overcome this disadvantage, various structures, for example Bus, Star, Tree topology, have been proposed. Because many optical couplers used in such structures induce large optical losses, highly sensitive detection is necessary. We report TDM/WDM Tree Topology-FBG sensing based on heterodyne detection technique.