Bending sensors based on fiber Bragg gratings: The key role of the mean effective index. (5th October 2017)

• Record Type: Journal Article
• Authors: Guyard, R.; Leduc, D.; Lecieux, Y.; Lupi, C.; Potet, J.; Beaucé, J.; Douay, M.; Lablonde, L.
• Is Part Of: Europhysics letters. Volume 119:Number 2(2017:Jul.)
• Publication Date: 2017-10-05
• Subjects: 42.79.Dj -- 42.81.Pa -- 06.30.Bp; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/119/24004
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: In this article we show that the Bragg wavelength variation induced by a curvature in the fiber Bragg grating is related to both the variation of the effective index and the variation of the coupling coefficient of counter-propagating modes. The weighting coefficient between the two variables is the mean effective index of the grating. The two effects act in opposition as proved both by our model and by our experimental observations. This work can be used to design strain sensors insensitive to bending, or, on the contrary, bending sensors insensitive to strain.