HYDROSTATIC PRESSURE SENSOR BASED ON A GOLD-COATED FIBER MODAL INTERFEROMETER USING LATERAL OFFSET SPLICING OF SINGLE MODE FIBER

A novel hydrostatic pressure sensor based on a gold-coated flber modal interferometer (FMI) is proposed and demonstrated. Two single mode flbers (SMFs) are spliced with a lateral ofiset which forms a single-end FMI. The single-end FMI is gold-coated to enhance the re∞ectivity and to avoid the in∞uence of any unwanted light from getting into the sensor. Relative re∞ection spectra of the proposed FMIs with difierent sensing SMF lengths or difierent lateral ofisets are experimentally investigated. A high hydrostatic pressure sensor test system is proposed for the testing of the proposed FMI pressure sensor. The performance of a gold-coated FMI pressure sensor based on a 12- mm sensing SMF has been experimentally investigated. The proposed pressure sensor has a sensing range from 0 to 42MPa and a sensitivity of 53pm/MPa.