Fabrication Friendly Plasmonic Metasurface Sensing and Switching Configuration Based on Plasmonic Induced Absorption: Analytical and Numerical Evaluation

Optical sensing and switching characteristic for a novel plasmonic metasurface structure are verified based on numerical and analytical evaluations for the proposed structure formed by metal-dielectric-metal (MDM) sandwiched layers. The application of MDM metasurfaces for sensors on plasmon-induced absorption (PIA) effect has been less studied. However, in this work, a planar plasmonic metasurface made of a ring and a bar cut-out nanostructures with a very small footprint in size of less than half of the operation wavelength is proposed to realize the PIA mechanism at near-infrared frequency regime. Moreover, by harnessing the incident light, the narrow-band and perfect absorption resonances occur at the wavelengths of 1133 and 1698 nm with highly enhanced electric fields around the nanostructure. This article is numerically studied using finite-difference time-domain (FDTD) method. Then, analytical analysis has been performed by transfer matrix method (TMM). The sensitivity values for the first and second resonances are 742.42 nm/RIU and 1684 nm/RIU, respectively. The figure of merit (FoM) values for those resonances are 68.74 and 40.09, respectively. Furthermore, it has been shown that by changing the polarization employed, the proposed nanostructure behaves as a plasmonic switch.