title: Fiber Mach-Zehnder interferometer based on microcavities for high-temperature sensing with high sensitivity.
abstract: A high-temperature sensor based on a Mach-Zehnder interferometer (MZI) in a conventional single-mode optical fiber is proposed and fabricated by concatenating two microcavities separated by a middle section. A femtosecond laser is used to fabricate a microhole on the center of a fiber end. Then a micro-air-cavity is formed by splicing the microholed fiber end with a normal fiber end. The interferometer is applied for high-temperature sensing, in the range of 500-1200 °C, with a sensitivity of 109 pm/°C that, to the best of our knowledge, is highest in silica fiber temperature sensors. Also, the interferometer is insensitive to external refractive index (RI), which is desirable for temperature sensors.
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, 100081, China. jianglan@bit.edu.cn
authors.forename: L
authors.initials: L
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Wang