(Received November 30, 1992; accepted for publication February 20, 1993)
A design for a high sensitivity sensor utilizing the flexural vibration of circular disks, as the sensing element of an interferometric fiber-optic hydrophone to detect underwater sounds has previously been reported. To improve the durability of this type of sensor against static pressure, a sensor with a pressure-balancing structure was fabricated and tested. The measured receiving sensitivity of the sensor in the sea agreed reasonably well with the calculated sensitivity. The sensitivity measured in an acoustic coupler was independent of the static pressure up to 5 MPa.
KEYWORDS:underwater sound, acoustic sensor, fiber-optic hydrophone, flexural disk sensor, pressure-balancing structure