Novel Approach for Design of Fiber-Based Evanescent Wave Sensors for the Mid-Infrared Spectroscopy

Abstract

In this paper, a theoretical approach based on electromagnetic theory of optical fibers is used for analysis and optimisation of sensing elements of the fiber-based evanescent wave sensors for the mid-IR spectroscopy. We have demonstrated that excitation of the higher-order modes of a single-index fiber, engineering of refractive index profile of a core-clad fiber and a fiber bending are efficient ways for the sensor optimisation.