摘要
Tunability,ultracompact design,high group index,low loss,and broad bandwidth are desired properties for integrated optical delay lines(ODLs).However,those properties are challenging to achieve simultaneously in the visible region.This paper proposes a tunable hexagonal boron nitride topological optical delay line(ODL)in the visible region based on valley photonic crystals.The topological edge state from the beard-type boundary allows the achievement of an ultralow group velocity close to zero,which results in a large group index of 629 at 645 nm.Moreover,we demonstrate tuning of the slow-light wavelength and optical delay times with electrically tunable liquid crystals by applying external voltage.The device has an ultracompact size of 5μm×2.7μm with an optical delay distance of 25a(a is the lattice constant)and a delay time of 12 ps.Our design can provide a new possibility for designing ODLs working in the visible region for optical communication and quantum computing systems.
作者
费宏明
武敏
林瀚
杨毅彪
肖连团
Hongming Fei;Min Wu;Han Lin;Yibiao Yang;Liantuan Xiao(College of Physics,Taiyuan University of Technology,Taiyuan 030024,China;College of Information Engineering,Shanxi Vocational University of Engineering Science and Technology,Jinzhong 030619,China;College of Science,RMIT University,Melbourne,Victoria 3000,Australia;College of Electronic Information and Optical Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
基金
This work was supported by the National Key Research and Development Program of China(No.2022YFA1404201)
the Australian Research Council Future Fellowship(No.FT220100559)
the National Natural Science Foundation of China(NSFC)(No.U23A20375).
