Manifestation of a highly sensitive evanescent wave absorption-based refractive index sensor realized by radiating with an optical Airy beam

Abstract

In this research, a theoretical perception on the notion of an ultra-high sensitive evanescent wave-based fiber-optic refractive index sensor has been proposed by shining an optical Airy beam. The sensing configuration consists of a multimode fiber which is decladded from the middle to aptly sculpt the evanescent wave. In presence of the Airy beam, effectual coupling of high-order modes within the sensing structure has been affirmed by using the classical wave-optic model. To corroborate our theoretical study, an Eigenmode expansion solver (EME) propagation analysis was conducted in commercially offered Mode solution software (Lumerical Inc.) to investigate the transmission characteristics of Airy beam within the waveguide structure. Compared with conventional Gaussian beam-based sensor, the proposed refractive index sensor renders a maximum 19.15 fold superior sensitivity of 992.39 dB/RIU with an admirable sensing resolution of ∼1.00 × 10−5 RIU. Thus, this nascent-class of beam called Airy beam manifests a new degree of freedom which demonstrates the viability of the proposed scheme for the usage of chemical and biological sensing.