Hydrostatic Pressure Insensitive Dual Polarization Fiber Grating Laser Hydrophone

A hydrostatic pressure insensitive fiber-optic hydrophone based on the integration of a dual polarization fiber grating laser and an elastic diaphragm is proposed and experimentally demonstrated. The diaphragm converts acoustic pressure into transversal force onto the fiber laser but shows no response to the hydrostatic pressure. Therefore, the beat frequency is sensitive to acoustic signal but insensitive to the hydrostatic pressure.