Chiral transmission by an open evolution trajectory in a non-Hermitian systemOACSTPCD
Chiral transmission by an open evolution trajectory in a non-Hermitian system
Exceptional points(EPs),at which two or more eigenvalues and eigenstates of a resonant system coalesce,are associated with non-Hermitian Hamiltonians with gain and/or loss elements.Dynamic encircling of EPs has received significant interest in recent years,as it has been shown to lead to highly nontrivial phenomena,such as chiral transmission in which the final state of the system depends on the encircling handedness.Previously,chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time-(PT-)or anti-PT-symmetric systems.Although chiral transmission of symmetry-broken modes,more accessible in practical photonic integrated circuits,has been realized by establishing a closed trajectory encircling EPs in anti-PT-symmetric systems,the demonstrated transmission efficiency is very low due to path-dependent losses.Here,we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed trajectory.Specifically,we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes(not modes in PT-and anti-PT-symmetric systems),demonstrating that this platform enables high-efficiency chiral transmission,with each eigenmode localized in a single waveguide.This concept is experimentally implemented in a coupled silicon waveguide system at telecommunication wavelengths.Our work provides a new evolution strategy for chiral dynamics with superior performance,laying the foundation for the development of practical chiral-transmission devices.
Xiaoqian Shu;Lin Chen;Qi Zhong;Kai Hong;Oubo You;Jian Wang;Guangwei Hu;Andrea Alù;Shuang Zhang;Demetrios N.Christodoulides
Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China||Zhejiang Lab,Hangzhou 311121,ChinaWuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China||Shenzhen Huazhong University of Science and Technology Research Institute,Shenzhen 518063,ChinaCREOL,College of Optics and Photonics,University of Central Florida,Orlando,Florida 32816,USAWuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,ChinaDepartment of Physics,The University of Hong Kong,Hong Kong,ChinaSchool of Electrical and Electronic Engineering,Nanyang Technological University,50 Nanyang Avenue,Singapore 639798,SingaporePhotonics Initiative,Advanced Science Research Center,City University of New York,New York,NY 10031,USA
《光：科学与应用（英文版）》 2024 (004)
628-636 / 9
National Natural Science Foundation of China(Grant No.12074137),National Key Research and Development Project of China(Grant No.2021YFB2801903),Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.JCYJ20220530161010023),State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology),and AFOSR MURI(FA9550-18-1-0235).
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