Plasmonic Nanoantenna Array-Based Sensor for Air Parameters Monitoring Purpose

Plasmonic nanoantennas have earned significant acclaim for their remarkable ability to couple light from free space into sub-wavelength-sized structures and to enhance the confinement of the electric field. One of the most promising applications of plasmonics is refractive index sensing. To study the optical properties and near-field calculations of the nanoantenna, three-dimensional finite-difference time-domain (FDTD) simulations were conducted using commercially available Maxwell equation solvers, such as Lumerical software. A significant enhancement in electric field intensity and maximum absorption cross-section were observed when an array of plasmonic nanoantennas was used compared to a plasmonic nanoantenna dimer. The proposed device is used to sense changes in major air parameters such as carbon dioxide (CO2) gas concentration and atmospheric pressure. Sensitivities as high as 488 nm/RIU and 500 nm/RIU, respectively, were achieved after analyzing both cases.