Chinese Optics Letters, Vol. 17, Issue 12, 120603 (2019)
Investigation on temperature characteristics of weak fiber Bragg gratings in a wide range
Xiaojun Fan1,2,3, Junfeng Jiang1,2,3,*, Xuezhi Zhang1,2,3,**, Kun Liu1,2,3, Shuang Wang1,2,3, and Tiegen Liu1,2,3
- 1School of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China
- 2Tianjin Optical Fiber Sensing Engineering Center, Institute of Optical Fiber Sensing of Tianjin University, Tianjin 300072, China
- 3Key Laboratory of Opto-electronics Information Technology, Ministry of Education, Tianjin University, Tianjin 300072, China
A weak fiber Bragg grating (WFBG) is an ideal quasi-distributed optical fiber sensor. Special attention should be paid to the spectrum and sensing performance of the WFBG at extreme temperatures due to its poor reflection intensity. In this Letter, the temperature characteristics of the WFBG from 252.75°C to 200.94°C are experimentally investigated. Five WFBGs with reflectivity from ～0.25% to ～10% are used in the experiments. The reflectivity variations and wavelength shifts at different temperatures are studied. Experimental results show that the WFBG can survive and work at extreme temperatures, but the performance is affected significantly. The reflectivity is affected significantly by both cryogenic temperature and high temperature. The temperature responses of Bragg wavelengths in the wide temperature range are also obtained.