Detection of acoustic pressure with hollow-core photonic bandgap fiber

Abstract

We report the results of our preliminary investigation on the use of hollow-core photonic bandgap fiber (HC-PBF) for hydrophone application. The response of the commercial HC-1550-02 fiber to acoustic pressure, in terms of normalized responsivity (NR), is measured to be - 334.4dB re 1μPa⁻¹. This agrees well with the theoretically predicated value of -331.6dB re 1μPa⁻¹ and is about 15dB higher than that of the conventional fiber (HNSM-155). With straightforward fiber structure modifications (thinner outer silica cladding and higher air-filling ratio of inner microstructured cladding), the NR could be further enhanced to - 310dB re 1μPa⁻¹