Improvements relating to optical sensing systems.

摘要

An optical sensing system (e.g. hydrophone) comprises a plurality of laser light sources for producing light signals of different frequencies which are combined by a Bragg cell and launched into a single optical fibre leading to an optical sensor array arrangement. This sensor array arrangement comprises a plurality of optical sensors separated by redirecting means for redirecting light signals along an optical fibre in time displaced relationship to an optical detector. <IMAGE>