Fiber-Optic Thermal Sensor for TiN Film Crack Monitoring
Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan
Department of Industrial Engineering and Management, Fortune Institute of Technology, Kaohsiung 831, Taiwan
Department of Mechanical Engineering, Wu Feng University, Chiayi County 62153, Taiwan
Author to whom correspondence should be addressed.
Materials 2017, 10(11), 1297; https://doi.org/10.3390/ma10111297
Received: 29 September 2017 / Revised: 2 November 2017 / Accepted: 7 November 2017 / Published: 11 November 2017
(This article belongs to the Special Issue Selected Papers from IEEE ICICE 2017)
The study focuses on the thermal and temperature sensitivity behavior of an optical fiber sensor device. In this article, a titanium nitride (TiN)-coated fiber Bragg grating (FBG) sensor fabricated using an ion beam sputtering system was investigated. The reflection spectra of the FBG sensor were tested using R-soft optical software to simulate the refractive index sensitivity. In these experiments, the temperature sensitivity of the TiN FBG was measured at temperatures ranging from 100 to 500 °C using an optical spectrum analyzer (OSA). The results showed that the temperature sensitivity of the proposed TiN FBG sensor reached 12.8 pm/°C for the temperature range of 100 to 300 °C and 20.8 pm/°C for the temperature range of 300 to 500 °C. Additionally, we found that the produced oxidation at temperatures of 400-500 °C caused a crack, with the crack becoming more and more obvious at higher and higher temperatures.