スマート構造用モード領域分布型光ファイバセンサの感度解析

抄録

Modal domain distributed fiber optic sensors by using a birefringent single mode fiber can be applied for measurement of mode coupling distribution along a fiber attached to a structure. Some fundamental experiments were conducted to understand relations between the mode coupling and the external force. The relations were derived theoretically by using a coupled mode equation. Experiments were conducted to measure the mode couplings of a coated or an uncoated fiber subjected to a transverse load at one point. Experimental results showed relation between a mode coupling and an external load was almost linear on a logarithmic graph. It was found that an uncoated fiber measured load more quantitatively than a coated fiber. A fiber optic load sensor module for a serial multiplexed sensor system was developed for future application of the present study. This technique can be combined with the p-OCDR (phase-modulating Optical Coherence Domain Refiectometry) technique developed by K. Hotate et al. to quantify the applied loads along a fiber on structures.