We report on the first field demonstrations of a depth compensated, light weight, compact fibre laser hydrophone array
for a rapidly deployable seabed SONAR system. The demonstration was held in Jervis Bay off the east coast of
Australia. Using SONAR processing techniques, we were able to detect, characterise, and coherently process multiple
An acoustic vector sensor based on distributed feedback fibre laser technology is reported. The sensor is designed as an
accelerometer that will sense acceleration induced by the difference in acoustic pressure across the sensor. Experimental
measurements demonstrate that the sensor has excellent response characteristics and sufficient cross-axis discrimination
to be a useful acoustic vector sensor.
A pressure compensated distributed feedback fibre laser hydrophone is described. Pressure compensation is achieved by
incorporating an air-filled bladder and acoustic filter into the hydrophone making it insensitive to hydrostatic pressures to
depths of up to 50m.
We demonstrate an electro-optic phase modulator based demodulation system for acoustic frequency modulated
optical signals. The system is free from polarisation fading and is capable of retrieving high frequency signals,
ultimately limited by the time of flight of the interferometer itself. Digital interrogation method is based on the Carré
algorithm and does not require fine tuning of the introduced phase and is suitable for simultaneous phase retrieval at
multiple wavelengths without the need for correction transfer filters.