Characterization of an optical multilayer hydrophone for use as broadband ultrasound reference receiver - comparison with PVDF membrane hydrophones

The performance of an optical multilayer hydrophone for ultrasound detection comprising a thin high-finesse dielectric interference filter structure deposited onto a plane glass plate is experimentally investigated. The characterization given covers the frequency response in the range from 1 to 75 MHz, the sensitivity, the stability and the directional response. The results are compared with typical characteristics of PVDF hydrophones. The optical multilayer hydrophone is well suited for use as a broadband reference receiver for secondary hydrophone calibration, in particular because of the constant response in a wide frequency range. In an application example the complex-valued broadband frequency response of a fiber-optic hydrophone is determined using this reference.