Simultaneous measurement of high refractive index and temperature based on SSRS-FBG

• Main Authors: Saimon, S. M., Mohd. Noor, M. Y., Abdullah, A. S., Salim, M. R., Ibrahim, M. H., Azmi, A. I.
• Format: Article
• Published: Institute of Electrical and Electronics Engineers Inc. 2021
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utm.my/id/eprint/94474/; http://dx.doi.org/10.1109/LPT.2021.3088849

In this study, a novel and simple optical fiber sensor is proposed, simulated, and experimentally demonstrated for simultaneous measurement of high refractive index (RI) and temperature. The sensor consists of a section of single-mode-silica rod-single-mode (SSRS) fiber structure cascaded to fiber Bragg grating (FBG) (SSRS-FBG). The simultaneous measurement of high RI and temperature was realized in this study by monitoring the output power level and wavelength shift of the SSRS-FBG single dip transmission spectrum corresponding to different surrounding high RI and ambient temperature values. The experimental results showed that the cascaded sensor had a sensitivity of 108.07 dBm/RIU for high RI ranging at 1.45-1.531, while the temperature sensitivity was 9.31 pm/°C from 35 °C to 85 °C. This sensor is most suitable for high RI applications, such as for monitoring oil quality stored in terminal and power transformers.