Optical Fibre Refractive Index Sensor in a Hybrid Fibre Grating Configuration

Alwis, Lourdes; Sun, Tong; T.V. Grattan, Kenneth

Abstract

A temperature compensated Refractive Index (RI) sensor incorporating a Long Period Grating (LPG) and a Fibre Bragg Grating (FBG) in a series configuration has been developed and evaluated. The LPG was used as a RI sensor allowing it to respond to external RI variations while the FBG was used for temperature compensation. The LPG and FBG wavelengths were chosen to be within suitable spectral bandwidths for efficient interpretation of both RI and temperature. The performance of the hybrid sensor was evaluated for use as a chemical sensor by varying sodium chloride (NaCl) concentrations in water from 0.25 – 2%NaCl and temperature from 10-95 oC and by recording its corresponding attenuation band shifts. The sensitivity of the hybrid sensor to NaCl concentration and temperature is calculated to be 0.61 nm/%NaCl and 8 pm/oC respectively.

Citation

Alwis, L., Sun, T., & T.V. Grattan, K. (2015). Optical Fibre Refractive Index Sensor in a Hybrid Fibre Grating Configuration. Procedia Engineering, 120, 11-14. https://doi.org/10.1016/j.proeng.2015.08.555

• Journal Article Type: Conference Paper
• Conference Name: EuroSensors
• Start Date: Sep 6, 2015
• End Date: Sep 9, 2015
• Acceptance Date: Jun 1, 2015
• Online Publication Date: Sep 11, 2015
• Publication Date: Sep 11, 2015
• Deposit Date: Dec 11, 2017
• Publicly Available Date: Dec 11, 2017
• Journal: Procedia Engineering
• Print ISSN: 1877-7058
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 120
• Pages: 11-14
• DOI: https://doi.org/10.1016/j.proeng.2015.08.555
• Keywords: Fibre Bragg grating (FBG), Long period grating (LPG), Refractive index (RI),
• Public URL: http://researchrepository.napier.ac.uk/Output/947680