HYDROPHONE MANDREL FOR PRECISE PLACEMENT OF GRATINGS

摘要

A method and apparatus for reducing the difficulty of controlling the length of a section of optical waveguide wrapped around a mandrel separating Bragg gratings forming an interferometric sensor are provided. The section of optical waveguide may be wrapped on a mandrel having at least two different outer diameters. T he mandrel may also include one or more bores for receiving and protecting the Bragg gratings.