Directional interacting whispering-gallery modes in coupled dielectric microdisks

Abstract

We study the optical interaction in a coupled dielectric microdisks by\ninvestigating the splitting of resonance positions of interacting whispering\ngallery modes (WGMs) and their pattern change, depending on the distance\nbetween the microdisks. It is shown that the interaction between the WGMs with\nodd parity about y-axis becomes appreciable at a distance less than a\nwavelength and causes directional emissions of the resulting interacting WGMs.\nThe directionality of the interacting WGMs can be understood in terms of an\neffective boundary deformation in ray dynamical analysis. We also discuss about\nthe oscillation of the splitting when the distance is greater than a\nwavelength.\n