Deep Fiber Optic Vector Sensor Array

Vibration Impact and Pressure (VIP) Sensors proposes to develop a compact Fiber Optic Vector Sensor (FOVS) Array to be deployed in an expendable sonobuoy and operated close to the ocean bottom (below critical depth). The FOVS consists of an omnidirectional hydrophone which provides sounds amplitude and a triaxial/biaxial accelerometer that provide the sounds direction.A pair of single mode optical fibers interconnect multiple, miniature, fully passive (no electrical wires) FOVS located up to 6 km below sea level to the sonobuoys Lower Electronic Module. A broadband light source from the electronic module excites the FOVS array. Each of the optical sensors, built to work at unique ranges of the optical spectrum, modulates the light within its corresponding wavelength range in proportion to the measurand; therefore the light returning from the FOVS contains the information of all the sensors at different preset wavelength slots in a wave division multiplexing (WDM) fashion.The optical sensors are micromachined MOMS (Micro Optical Mechanical System) silicon chips which consume no electrical power. The low power consumption of the electronic module is mainly for the light source and for processing the signals. The MOMS technology allows optimization of the sensors performance and low cost production rates.