Controlled Hybridization of Plasmonic and Optical Modes for Low-Loss Nano-Scale Optical Confinement with Ultralow Dispersion

Abstract

A photonic-waveguide at real nano-scales based on the concept of hybridization of plasmonic and photonic modes is designed and fabricated. A high-index layer of silicon to control vertical and lateral confinement is introduced under the nano-confinement layer of thermally grown SiO2, which together with optimized waveguide-width provides low-loss guidance of hybrid-plasmonic-mode. A 11-nm thick SiO2 on silicon provides us an optical-confinement at real nano-scales with an acceptably low loss of 7 dB/cm. Also, the proposed device exhibits ultra-low dispersion on introducing a grating in the silicon layer. In addition, the dispersion value 'crosses zero-dispersion' many times over a broad range of wavelength. © 1965-2012 IEEE.