摘要
Circular dichroism(CD)has shown very interesting possibilities as a means to characterize the chiral signal of a chiral structure.Here,we theoretically demonstrated enhanced and tunable CD in the visible light regime using a composite structure consisting of a double-layer metal grating gaped by a dielectric waveguide layer.Based on the coupling of the waveguide modes and the localized plasmonic resonances,the CD could reach a maximum value as high as 0.52 at635 nm,which is four times higher than the CD value obtained in a conventional double-layer grating without the waveguide coupling effect.Furthermore,the spectral positions of the enhanced CD bands could be easily tuned by controlling the structural parameters.The proposed hybrid double-grating and waveguide structures could have potential applications in chiral selective imaging,sensing and spectroscopy,especially where the transmission measurement is required.
作者
王刘丽
顾阳
陈怡静
倪亚贤
董雯
Liu-Li Wang;Yang Gu;Yi-Jing Chen;Ya-Xian Ni;Wen Dong(School of Physical Science and Technology,Soochow University,Suzhou 215006,China;Soochow College,Soochow University,Suzhou 215006,China)
基金
Project supported by the National Natural Science Foundation of China(Grant No.11474215)。