Optical Fibre Hydrophones and Hydrophone Arrays

Abstract

This contribution consists of two discrete sections. The first discusses the basic concepts of, and engineering progress with, a reflectometric method of polling the acoustically-induced length variations of a passive array of optical fibre hydrophones. The second part of the tutorial paper describes an alternative sensor, which, in its simple uncompensated form has been considered for use as a single hydrophone element by the U.S. Naval Research Laboratories. The present paper does not give any account of its use for this purpose, but describes how such a sensor may in general be compensated for ambient common-mode pressure or temperature changes and how it may be configured for practical sensors of pressure or magnetic field. The latter technique, therefore, in addition to its possible relevance to hydrophone systems, has a more general application to the field of optical fibre sensors.