Open AccessA robust scheme for unidirectional emission from a hybrid whispering gallery cavity system based on transformation optics
Author(s) -
Jeong-Hee Lim,
Yong-Hoon Lee,
Inbo Kim,
Jinhang Cho,
Seog-Hoon Rim,
Sang-Jun Park,
Muhan Choi
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.423563
Subject(s) - whispering gallery wave , optics , resonator , transformation optics , transformation (genetics) , optical cavity , physics , optical microcavity , embedding , materials science , optoelectronics , laser , metamaterial , biochemistry , chemistry , artificial intelligence , computer science , gene
Using the transformation cavity, a gradient index cavity designed by transformation optics, we propose a hybrid resonator system to extract unidirectional narrow-beam emission from high-Q whispering gallery modes by embedding a transformation cavity inside a deformed uniform index cavity that exhibits unidirectional narrow-beam emission. For effective mode coupling between the transformation cavity and enclosing cavity, the embedded transformation cavity is designed to have bidirectional evanescent emission, which enables most of the emission from the transformation cavity to be laterally incident on the rim of the enclosing deformed cavity. Consequently, ultrahigh-Q resonances of this system can provide a sharp free-space light output, which is difficult to achieve by embedding a homogeneous disk cavity instead of the transformation cavity.