Plasmonic Grid Array of Gold Nanorods for Point-to-Point Optical Communications

A novel wire-grid array of nanorods is introduced. The array consists of five gold radiating rods and four gold perpendicular connecting rods. Each rod represents a plasmonic transmission line supporting single Surface Plasmon Polariton mode guided to the interface between the metal and surrounding dielectric. The propagation characteristics of this single strip plasmonic transmission line are studied using an integral equations formulation solved using the Method of Moments. The new array is designed for operation at a wavelength of 1.55 μm, which is commonly used by optical communication systems. The overall physical and electrical sizes of the array are (0.68-by-1.05 μm) and (λ_g-by-3λ_g/2), respectively. The maximum directivity of the proposed wire-grid nantenna array on top of a substrate with refractive index of 2 reaches 15.24 dBi. The proposed wire-grid nantenna array has a symmetric radiation pattern with reasonable side-lobe-level and extremely low cross-polarization level.