Black Phosphorous and Cytop Nanofilm-Based Long-Range SPR Sensor with Enhanced Quality Factor

Abstract

This numerical work proposes two novel designs of long-range surface plasmon resonance sensors (LRSPR) using two different coupling prisms. The performance analysis of the proposed sensor has been investigated using the performance parameters like quality factor ( $Q$ ), detection accuracy (DA), sensitivity ( $S$ ), and full-width half maximum (FWHM). The transfer matrix method (TMM) has been employed to compute reflectance. The role of the basic recognition element (BRE) has been played by the popular two-dimensional (2D) material, black phosphorus (BP), due to its many optoelectrical features. The maximum obtained values for $Q$ , DA, and $S$ are 3333.25 $\left(1/\text{RIU}\right)$ , 250 $\left({\text{degree}}^{-1}\right)$ , and 13.33333 degree/RIU for 2S2G coupled sensor design and 3055.5 $\left(1/\text{RIU}\right)$ , 83.33 $\left({\text{degree}}^{-1}\right)$ , and 36.66667 degree/RIU for BK7 coupled sensor design. The operating wavelength of 633 nm, followed by the principle of attenuated total reflection (ATR), has been employed to carry out the theoretical investigation.