Optical fiber temperature sensor based on Mach-Zehnder interferometer coated with a film of PDMS

An optical fiber temperature sensor by using a Mach-Zehner interferometer coated with a film of PDMS was proposed. The Mach-Zehner interferometer is made up of two Bowknot Type Tapers (BTTs) and a single mode fiber. The surface of the two BTTs was coated with a film of PDMS. The energy distribution of the two BTTs was simulated by using the finite element means. The proposed sensor structure has a linearity correlation of 98.46% in temperature responses. Temperature detection sensitivity of 0.1957nm/ °C was obtained under the temperature range from 40 °C to 120°C, which is about 10 times of the similar sensors with a sensitivity of tens pm/ °C.