We describe a theoretical and experimental study of an intensity-based, dual-wavelength referenced fiber optic temperature sensor utilizing temperature-induced spectral shifts of optical thin-film interference coatings, deposited on a sensor fiber end. We present coating design considerations that lead to significant increase in transition region spectral shifts and coating-reflected signal modulations, for sensitive temperature measurement. Experimental results demonstrate that high density coating-based sensors provide consistent and repeatable temperature sensing, while low density coating-based sensors experience significant and inconsistent spectral variations and degradation under temperature cycling.

Date Published: 9 March 1994
PDF: 8 pages
Proc. SPIE 2070, Fiber Optic and Laser Sensors XI, (9 March 1994); doi: 10.1117/12.169929

Published in SPIE Proceedings Vol. 2070:
Fiber Optic and Laser Sensors XI
Ramon P. DePaula, Editor(s)