The Determination of the Sensitivity of Refractive Index Sensors

Abstract

A new approach to determining the sensitivity of refractive index sensors is proposed. It has been shown that relative and absolute sensitivity show different results, and also, for the first time, it is demonstrated that relative sensitivity has advantages over absolute sensitivity. In addition, the influence of the relative width of the photonic band gap and the difference in the refractive indices of the layers on the sensitivity are examined and the corresponding dependences of these parameters are obtained. We propose these parameters as a convenient tool for optimizing the sensitivity of sensors based on defective photonic crystals. Finally, results are obtained regarding the behavior of the defect mode at the center of the photonic band gap of one-dimensional photonic crystals.

On the sensitivity of defect modes outside the first photonic bandgap in optical sensors based on defected 1D photonic crystals

“…The thicknesses of the first (d 1 ) and second (d 2 ) layers of the PC were determined to achieve maximum sensitivity for DMs in the first and then in the second PBG. It has been shown in [68] that the maximum sensitivity is observed when the width of the PBG is maximal. It is also known that maximum sensitivity can only be obtained when the DM is at the center of the PBG, and for the mirror symmetry structures [58].…”