Partially multiplexing sensor network exploiting low coherence interferometry

A partially multiplexed fiber-optic-based sensor network based on low coherence interferometry is reported for which the scanning interferometer simultaneously sweeps the coherence-matched region of each sensor. The advantage of this approach is that the signal-to-noise ratio is maximized while the cross talk between sensors is minimized. The normal requirement that each sensor must be fabricated with a different length also does not apply. The concept is demonstrated by multiplexing two bulk optic Michelson interferometers. A resolution of ~ 50 nm with an operational range of 200 microm was achieved in the prototype system.