一种基于纳米环-柱结构的高效非线性超表面  

A Highly Efficient Nonlinear Metasurface Based on Nanoring-Rod Structures

作　　者：张梦蝶 王文涛 孙朋 黄辉 董凤良[2,3] 胡源 褚卫国[2,3] Zhang Mengdie;Wang Wentao;Sun Peng;Huang Hui;Dong Fengliang;Hu Yuan;Chu Weiguo(School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun,Jilin 130022,China;Nanofabrication Laboratory,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology,Beijing 100190,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]国家纳米科学中心纳米加工实验室,中国科学院纳米科学卓越创新中心,北京100190 [3]中国科学院大学材料与光电研究中心,北京100049

出　　处：《光学学报》2021年第12期195-201,共7页Acta Optica Sinica

基　　金：国家自然科学基金(61875042,11627803);中国科学院青年创新促进会(Y201911);中国科学院科研仪器设备研制项目(Y8512911)。

摘　　要：为了通过光学元件结构设计实现高效非线性转换,提出了一种由金纳米圆环、开口金谐振环和四个砷化镓纳米柱构成的结构单元,来形成纳米环盘谐振腔和开口谐振环混合结构超表面。利用开口谐振环和纳米环共同激发Fano共振效应增强局域电场,并将具有高二次非线性极化率的GaAs介质纳米柱作为二次谐波转换器,从而降低吸收损耗,提高非线性转化效率。此外,在基频和倍频处偶极子共振形成的模式匹配进一步增强非线性转化。数值模拟计算得到的二次谐波转换效率高达0.15%。该研究为具有高非线性转化效率的新型纳米光学元器件的探索和设计提供了新思路。In order to achieve highly efficient nonlinear conversion through the design of optical elements,a structural unit composed of an Au nanoring,an Au split-ring resonator(SRR),and four GaAs nanorods is proposed to form a nanoring disk resonant cavity and a hybrid structure metasurface of the open resonant ring.The SRR and nanoring jointly excited Fano resonance to enhance the local electric field.The four GaAs nanorods with high second nonlinear polarizability in subatoms are used as second harmonic generation converters to reduce the absorption loss and improve the nonlinear conversion efficiency.Furthermore,the mode matching of dipole resonance at both the fundamental frequency and the second harmonic improves the nonlinear conversion efficiency.The efficiency for second harmonic generation is up to 0.15%through simulations.Therefore,this research provides new ideas for the exploration and design for novel optical components with high nonlinear conversion efficiency.

关 键 词：非线性光学 超表面 谐波振荡 Fano共振 

分 类 号：O437.1[机械工程—光学工程]