Dielectric film based optical fiber sensor using Fabry-Perot resonant structure

We presented an optical fiber sensor based on dielectric film which is used to construct a Fabry-Perot structure. The Fabry-Perot resonant structure is consist of 11 porous thin films manufactured by electron beam physical vapor deposition. Since the films are porous material, the proposed fiber sensor structure is appropriate to detect the refractive index of liquid substances. In the refractive index detection experiments, the sensor probe possesses a refractive index sensitivity of 105 nm/RIU and a resolution of 2×10−3 RIU. Cycling test results show that the prepared sensor probe has response time of 5 s and good repeatability.