Tip Packaged High-Temperature Miniature Sensor Based on Suspended Core Optical Fiber

A tip packaged high-temperature miniature sensor constructed by a suspended-core optical fiber (SCF) is presented and experimentally demonstrated. An SCF with a short length spliced to the single-mode fiber (SMF) is utilized to build the Fabry-Perot interferometer (FPI). A section of SMF acting as a tip package is spliced to the end of the SCF, which gives the sensor immunity of the external refractive index (RI). The test processes of heating up and cooling down are repeated three times to evaluate the repeatability and hysteresis. The arithmetic means temperature sensitivity increases from 9.42 pm/ °C to 12.51 pm/ °C over the temperature range of 50-800 °C. Moreover, the maximum stability error is 5 °C within the high-temperature 800 °C duration period. This tip packaged sensor with simple fabrication, good repeatability, and good stability within a large dynamic range is advantageous to practical temperature measurement and massive production.