Suppression of parasitic interference n a fiber-tip Fabry-Perot interferometer for high-pressure measurements

We demonstrate a novel design and fabrication process for fiber-tip Fabry-Perot interferometric (FTFPI) pressure sensors which eliminates fringe envelopes in the reflection spectrum. The outer facet reflectivity and thickness of the FTFPI silica diaphragm were reduced through orthogonal rough-polishing of the fiber end facet. A silica FTFPI sample with a diaphragm thickness of similar to 10.7 mu m was produced and tested under hydraulic pressures ranging from 0 to 30 MPa. The proposed sensor achieved a pressure sensitivity of -284 pm/MPa at 1555 mu and could be a valuable new tool for high pressure measurements. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement