Spin-preserving chiral photonic crystal mirror  

作　　者：Behrooz Semnani Jeremy Flannery Rubayet Al Maruf Michal Bajcsy 

机构地区：[1]Institute for Quantum Computing(IQC),University of Waterloo,Waterloo N2L3G1 ON,Canada [2]Department of Electrical&Computer Engineering,University of Waterloo,Waterloo N2L3G1 ON,Canada [3]Department of Physics and Astronomy,University of Waterloo,Waterloo N2L3G1 ON,Canada

出　　处：《Light(Science & Applications)》2020年第1期1787-1798,共12页光（科学与应用)（英文版）

基　　金：funding from the Canada First Research Excellence Fund;supported by Industry Canada;an NSERC Discovery grant;Ontario’s Ministry of Innovation Early Researcher Award。

摘　　要：Chirality refers to a geometric phenomenon in which objects are not superimposable on their mirror image.Structures made of nanoscale chiral elements can exhibit chiroptical effects,such as dichroism for left-and right-handed circularly polarized light,which makes these structures highly suitable for applications ranging from quantum information processing and quantum optics to circular dichroism spectroscopy and molecular recognition.At the same time,strong chiroptical effects have been challenging to achieve even in synthetic optical media,and chiroptical effects for light with normal incidence have been speculated to be prohibited in thin,lossless quasi-two-dimensional structures.Here,we report an experimental realization of a giant chiroptical effect in a thin monolithic photonic crystal mirror.Unlike conventional mirrors,our mirror selectively reflects only one spin state of light while preserving its handedness,with a near-unity level of circular dichroism.The operational principle of the photonic crystal mirror relies on guided-mode resonance(GMR)with a simultaneous excitation of leaky transverse electric(TE-like)and transverse magnetic(TM-like)Bloch modes in the photonic crystal slab.Such modes are not reliant on the suppression of radiative losses through long-range destructive interference,and even small areas of the photonic crystal exhibit robust circular dichroism.Despite its simplicity,the mirror strongly outperforms earlier reported structures and,contrary to a prevailing notion,demonstrates that near-unity reflectivity contrast for opposite helicities is achievable in a quasi-two-dimensional structure.

关 键 词：MIRROR CRYSTAL circular 

分 类 号：O734[理学—晶体学]