Formation of quasi-bound states in the continuum in a single deformed microcavity  

作　　者：SHUAI LIU BO-HAN WU JEFFREY HUANG ZHESHEN ZHANG 

机构地区：[1]Department of Electrical Engineering and Computer Science,University of Michigan,Ann Arbor,Michigan 48109,USA [2]Research Laboratory of Electronics,Massachusetts Institute of Technology,Cambridge,Massachusetts 02139,USA

出　　处：《Photonics Research》2024年第11期2651-2659,共9页光子学研究(英文版)

基　　金：National Science Foundation(2317471,2326780)。

摘　　要：Bound states in the continuum(BICs)hold significant promise in manipulating electromagnetic fields and reducing losses in optical structures,leading to advancements in fundamental research and practical applications.Despite their observation in various optical systems,the behavior of BIC in whispering-gallery-modes(WGMs)optical microcavities,essential components of photonic integrated chips,has yet to be thoroughly explored.In this study,we propose and experimentally identify a robust mechanism for generating quasi-BIC in a single deformed microcavity.By introducing boundary deformations,we construct stable unidirectional radiation channels as leaking continuum shared by different resonant modes and experimentally verify their external strong mode coupling.This results in drastically suppressed leaking loss of one originally long-lived resonance,manifested as more than a threefold enhancement of its quality(Q)factor,while the other short-lived resonance becomes more lossy,demonstrating the formation of Friedrich–Wintgen quasi-BICs as corroborated by the theoretical model and experimental data.This research will provide a practical approach to enhance the Q-factor of optical microcavities,opening up potential applications in the area of deformed microcavities,nonlinear optics,quantum optics,and integrated photonics.

关 键 词：DEFORMED QUASI CONTINUUM 

分 类 号：O43[机械工程—光学工程]