Hollow Core Fiber Based Interferometer for High Temperature (1000 °C) Measurement

Dejun Liu, Dublin Institute of Technology
Qiang Wu, University of Northumbria at Newcastle
Chao Mei, Beijing University of Posts and Telecommunications
Jinhui Yuan, Beijing University of Posts and Telecommunications
Xiangjun Xin, Beijing University of Posts and Telecommunications
Arun Mallik, Dublin Institute of Technology
Fangfang Wei, Dublin Institute of Technology
Wei Han, Dublin Institute of Technology
Rahul Kumar, Northumbria University at Newcastle
Chongxiu Yu, Beijing University of Posts and Telecommunications
Shengpeng Wan, Nanchang Hangkong University, China
Xingdao He, Nanchang Hangkong University, China
Bo Liu, Nanjing University of Information Science & Technology, China
Gang-Ding Peng, University of New South Wales, Sydney
Yuliya Semenova, Dublin Institute of Technology
Gerald Farrell, Dublin Institute of Technology

Document Type Article

Journal of Lightwave Technology Vol. 36, Issue 9, pp. 1583-1590 (2018)


A simple, cost effective high temperature sensor (up to 1000 °C) based on a hollow core fiber (HCF) structure is reported. It is configured by fusion splicing a short section of HCF with a length of few millimeters between two standard single mode fibers (SMF-28). Due to multiple beam interference introduced by the cladding of the HCF, periodic transmission dips with high spectral extinction ratio and high quality (Q) factor are excited. However, theoretical analysis shows that minor variations of the HCF cladding diameter may result in a significant decrease in the Q factor. Experimental results demonstrate that the periodic transmission dips are independent of the HCF length, but spectral Q factors and transmission power varies with different HCF lengths. A maximum Q factor of 3.3×10 ${}^4$ has been demonstrated with large free spectral range of 23 nm and extinction ratio of 26 dB. Furthermore, the structure is proved to be an excellent high temperature sensor with advantages of high sensitivity (up to 33.4 pm/°C), wide working temperature range (from room temperature to 1000°C), high resolution, good stability, repeatability, relatively low strain sensitivity (0.46 pm/με), low cost and a simple and flexible fabrication process that offers a great potential for practical applications. A thorough theoretic analysis of the HCF based fiber structure has been proposed. The experimental results are demonstrated to be well matched with our simulation results.