Embedded in-fibre Bragg grating (FBG) sensors appear to be ideally suited for structural health and usage monitoring of modern composite materials for aerospace and civil engineering-based applications as they have the following distinguishing advantages compared with conventional electrical sensors: (1) immunity to electromagnetic interference; (2) integration into composite materials without degration or significantly compromising the strength of the host material; (3) capacity of multiplexing many sensors in a single fibre lead allowing quasi-distributing measurement; (4) capacity of mass-production with good repeatability, making them potentially competitive with conventional electrical strain sensors.1 For these applications, it is necessary that the FBG sensors, embedded in or attached to the structure to be monitored, can be multiplexed efficiently to form a quasi-distributed network. So far, several multiplexing schemes for FBG’s, such as wavelength-division multiplexing (WDM), time-division multiplexing (TDM), and spatial-division multiplexing (SDM),2–5 have been investigated. The series multiplexing topologies, such as WDM and TDM, which are based on a single fibre link arrangement, are very efficient in power usage. The parallel topologies, such as SDM, allow each FBG sensor in the network to be operated independently, interchangeable and replaceable in the event of damage. For practical applications, it is necessary to combine both series and parallel topologies in order to create a real 2-D quasi-distributed FBG sensor network.
|Title of host publication||Applications of Photonic Technology 2|
|Editors||George A. Lampropoulos, Roger A. Lessard|
|Publication status||Published - 1997|