Microcavity fiber Fabry-Pérot interferometer with embedded golden thin film for high temperature measurement

We propose a new and ultracompact microcavity fiber Fabry-Pérot interferometer (MCFFPI) based on an ultrathin film of gold (Au) embedded in a single-mode fiber endface. The interference fringes of the proposed configuration with different cavity length are observed experimentally and verified the interference patterns are from the combination of Au thin film reflector and Fresnel reflection of fiber endface. Good linearity responses of the high temperature measurements are presented in the paper.