A simple technique for simultaneous measurement of the concentration of ethylene glycol and temperature by using a hybrid Sagnac interferometer is proposed and experimentally demonstrated. The hybrid Sagnac interferometer is configured by inserting a long-period fiber grating (LPFG) and a D-shaped polarization-maintaining fiber (PMF) into a Sagnac interferometer. By partially removing the cladding of the PMF, we make the Sagnac interferometer sensitive to ambient index by exposing the core region of the D-shaped PMF to external circumstance. The determinant of the sensitivity matrix of the proposed sensing probe is improved by using the negative temperature sensitivity of the LPFG.

Date Published: 2 June 2014
PDF: 4 pages
Proc. SPIE 9157, 23rd International Conference on Optical Fibre Sensors, 91570T (2 June 2014); doi: 10.1117/12.2058779

Published in SPIE Proceedings Vol. 9157:
23rd International Conference on Optical Fibre Sensors
José M. López-Higuera; Julian D. C. Jones; Manuel López-Amo; José Luis Santos, Editor(s)