Demonstration of a 16-sensor time-division-multiplexed Sagnac-interferometer-based acoustic sensor array with an amplified telemetry and a polarization-based biasing scheme

We have previously proposed the use of a Sagnac-interferometer in underwater acoustic sensor array applications. In these proposals, we described a configuration that passively desensitises the delay coil required by the Sagnac interferometer and passively eliminates polarization-induced signal fading (PISF). Additionally, an all-passive polarization-based biasing scheme that yields arbitrarily biased outputs was given. Here, we describe an experimental demonstration of a time-division-multiplexed (TDM) Sagnac-based array including all features described previously and supporting 16 individual sensors with an erbium-doped fiber amplifier (EDFA) telemetry.