A novel temperature-insensitive sensor probe is proposed and experimentally characterized. The sensor probe uses an etching cladding Few Mode Fiber Bragg Grating (FM-FBG) to sense the surrounding refractive indexes (SRI), which depends on the reflection peaks. To compensate for the temperature effect in SRI sensing, various guides modes in FM-FBG that have the different sensing behaviors are used for implementation. Both the propagation characteristics and operation principle of such a sensor are demonstrated in detail. A sensitivity of ~2 nm per refractive index unit (RIU) are obtained within the SRI range of 1.333–1.373. This sensor is temperature independent due to the temperature-insensitive nature of wavelength differential Δλ between the two reflection peaks of the etching cladding FM-FBG.

Date Published: 18 December 2019
PDF: 6 pages
Proc. SPIE 11340, AOPC 2019: Optical Fiber Sensors and Communication, 113401J (18 December 2019); doi: 10.1117/12.2547861

Published in SPIE Proceedings Vol. 11340:
AOPC 2019: Optical Fiber Sensors and Communication
Jie Zhang; Songnian Fu; Jun Yang, Editor(s)