A fiber-optic hydrophone with an acoustic filter

摘要

A novel Michelson interferometric fiber-optic hydrophone with a mechanical anti-aliasing acoustic filter, which consists of a two-hole cylindrical Helmholtz resonator, has been manufactured and tested. Experimental results show that this new fiber-optic hydrophone has a function of acoustic low-pass filtering. The low frequency sensitivity, as determined by the fiber interferometer and the sensing mandrel, is about -159dB re lrad/uPa. The frequency response has a break point near 1200Hz and a measured roll-off of 50dB/octave. The fiber-optic hydrophone is a prototype device for a class of sensors that used to eliminate aliasing in the future sonar systems. To our knowledge, this is the first time that such a fiber-optic hydrophone has been reported.