title: From non- to super-radiating manipulation of a dipolar emitter coupled to a toroidal metastructure.
abstract: Toroidal dipolar response in a metallic metastructure, composed of double flat rings, is utilized to manipulate the radiation pattern of a single dipolar emitter (e.g., florescent molecule/atom or quantum dot). Strong Fano-type radiation spectrum can be obtained when these two coupling dipoles are spatially overlapped, leading to significant radiation suppression (so-called nonradiating source) attributed to the dipolar destructive interference. Moreover, this nonradiating configuration will become a directionally super-radiating nanoantenna after a radial displacement of the emitter with respect to the toroidal flat-ring geometry, which emits linearly polarized radiation with orders of power enhancement in a particular orientation. The demonstrated radiation characteristics from a toroidal-dipole-mediated dipolar emitter indicate a promising manipulation capability of the dipolar emission source by intriguing toroidal dipolar response.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Xing-Xing
authors.initials: XX
authors.lastname: Xin
authors.forename: Jian
authors.initials: J
authors.lastname: Shao
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Wang
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.forename: Zheng-Gao
authors.initials: ZG
authors.lastname: Dong