MoiréMetasurface with Triple-Band Near-Perfect Chirality  

作　　者：吕博昆 李昊杰 贾倩文 杨国霞 曹凤朝 刘大禾 石锦卫 Bokun Lyu;Haojie Li;Qianwen Jia;Guoxia Yang;Fengzhao Cao;Dahe Liu;Jinwei Shi(Department of Physics and Applied Optics Beijing Area Major Laboratory,Beijing Normal University,Beijing 100875,China)

机构地区：[1]Department of Physics and Applied Optics Beijing Area Major Laboratory,Beijing Normal University,Beijing 100875,China

出　　处：《Chinese Physics Letters》2023年第5期41-46,共6页中国物理快报（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.12174031,91950108,and 11774035)。

摘　　要：Chiral metasurfaces have been proven to possess great potential in chiroptical applications.However,the multiband chiral metasurface with near-perfect circular dichroism has not been well studied.Also,the widely used bilayer metasurface usually suffers from the interlayer alignment and weak resonance.Here,we propose a twisted Moirémetasurface which can support three chiral bands with near-unity circular dichroism.The Moirémetasurface can remove the restriction of interlayer alignment,while maintaining a strong monolayer resonance.The two chiral bands in the forward direction can be described by two coupled-oscillator models.The third chiral band is achieved by tuning the interlayer chiral mode on resonance with the intralayer mode,to eliminate the parallel and converted components simultaneously.Finally,we study the robustness and tunability of the triple-layer Moirémetasurface in momentum space.This work provides a universal method to achieve three near-unity circular dichroism bands in one metasurface,which can promote applications of chiral metasurfaces in multiband optical communication,chiral drug separation,sensing,optical encryption,chiral laser,nonlinear and quantum optics,etc.

关 键 词：CHIRAL BANDS CIRCULAR 

分 类 号：TB34[一般工业技术—材料科学与工程] O43[机械工程—光学工程]