Dual-wavelength fiber optic temperature sensor

摘要

Abstract: 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. !14