Demodulation algorithm for spatial-frequency-division-multiplexed fiber-optic Fizeau strain sensor networks.

A demodulation algorithm for spatial-frequency-division-multiplexed fiber-optic Fizeau strain sensor networks with a large number of sensors is proposed to effectively reduce the cross talk between any two adjacent sensors and hence substantially enhance the multiplexing capability of the network, which is based on the Pisarenko algorithm. The cross talk between two fiber-optic Fizeau sensors is investigated experimentally. The experimental results show that a strain accuracy of better than +/-10 micro permittivity can be achieved even when the cavity length difference is approximately 100 microm. It was demonstrated that the multiplexing capability of the spatial-frequency-division-multiplexed fiber-optic Fizeau sensor network can be approximately 5 times greater than that of the conventional fast-Fourier-transform algorithm, and this can lead to achievement of a sensing network with a multiplexing capability of as many as 1000 Fizeau sensors.