A microbending fiber-optic hydrophone with a contical reflector has been designed and its wide frequency characteric measured in the 200-20,000Hz range. This hydrophone makes use of the reflection of acoustic waves by a cone. Then, the waves produce a periodic axial deformation of the multimode fiber which is wound around the cylindrical support and attenuate the guided light power of the fiber. Its voltage sensitivity and minimum detectable pressure are measured the same order as those of existing microbending hydrophones in the 200-1,500Hz frequency range. If a horn is used, it can have a large detection area without deteriorating its characteristics.
