Whispering Gallery Modes Formation in Small Nanocavities Based upon Crossed Nanobeam Structures

Abstract

Abstract:In this paper, we investigate conditions to form whispering gallery modes (WGMs) in small nanocavities (NCs) which are designed at the intersection area of couple of nanobeams (NBs) structures. Tapered air-holes at each branch of NBs have been employed as a part of mirror accompanied by curved-walls at cross junctions to form a small curved nanocavity. Simulations by finite element based commercial software, COMSOL Multiphysics 4.3 show that confined photonic modes are well established via WGM mechanism. Variation of modes wavelength and their field intensity profiles have been investigated. Quality factor, Q, as high as 198400 is obtained for a particular WGM at mode wavelength 1471.9 nm with computed modal volume as low as V mod ≈0.25(λ/n) 3 .