High-performance serial array of coherence multiplexed interferometric fiber-optic sensors

A noise analysis of coherence multiplexed interferometric sensors on a serial array configuration is presented. From the analysis it yields that in order to improve the system performance the source induced noise and the crosstalk noise must be lowered. The design of a low-coherence polarimetric sensor array multiplexed online is reported too. The very low-coherence length of the superluminescent source employed and the high precision of the technique used to distribute power among the different multiplexed sensing segments of optical fiber make it possible to overcome these two noise sources and to realize online distributed measurements with high spatial resolution (10 cm), high sensitivity (5 mu Hz), and low crosstalk (-40 dB) over a high number (up to 100) of equal-length segments of fiber.>