Fabry-Perot cavity based on sapphire-derived fiber for high temperature sensor

Abstract

An optical fiber high temperature sensor is demonstrated by using a special sapphire-derived fiber. An air cavity is easily created through splicing the sapphire-derived fiber with standard single mode fiber (SMF). Utilizing the air cavity as one reflecting face, a Fabry-Perot (F-P) interferometer is fabricated in the special fiber. Attributed to the high ratio alumina component, the F-P interferometer exhibits high sensitivity response to temperature variation within the range up to 1000 °C. The sensitivity is 15.7 pm/°C.