Distributed and multiplexed fibre-optic sensor systems

The unique advantages afforded in a number of application areas by the use of distributed fibre-optic sensor (DFOS) systems have been recognized by many researchers. Approaches described to date can be categorized as being either `intrinsic-distributed¿ or `quasi-distributed¿. In the case of intrinsic-distributed sensing, a single length of fibre forms an extended sensor element which senses the measurand field continuously over its entire length, whereas quasi-distributed sensing approaches utilize discrete fibre or non-fibre sensor elements typically arranged in a linear array. More geometrically versatile sensor network topologies can also be formed by multiplexing several discrete `point¿ sensors with common input/output fibres. This paper reviews this broad and rapidly expanding area of distributed and multiplexed optical fibre sensor technology.