介电常数近零复合超表面偏振相关非线性光学特性研究  

Polarization-dependent nonlinear optical properties of the epsilon-near-zero hybrid metasurface

作　　者：黄晶 陈龙龙 何源 李宁 缪丽丽 赵楚军 文双春 HUANG Jing;CHEN LongLong;HE Yuan;LI Ning;MIAO LiLi;ZHAO ChuJun;WEN ShuangChun(Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of LowDimensional Structure Physics and Devices,School of Physics and Electronics,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学物理与微电子科学学院,微纳光电器件及应用教育部重点实验室,低维结构物理与器件湖南省重点实验室,长沙410082

出　　处：《中国科学：物理学、力学、天文学》2023年第8期132-139,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:61975055)资助项目。

摘　　要：介电常数近零(Epsilon-near-zero,ENZ)复合超表面是一种由ENZ材料和金属纳米单元构成的超结构,因其可有效增强光场与物质相互作用而受到关注.本文设计并制备了基于氧化铟锡(Indium Tin Oxide,ITO)薄膜和金属纳米结构的非线性超表面,实验研究了该ENZ复合超表面宽波段偏振相关的非线性光学响应特性.与单一ITO薄膜相比,该ENZ复合超表面的非线性吸收系数和非线性折射率提高了2个数量级,并且可以有效增强三次谐波的产生.通过改变入射光的偏振状态,可以实现该复合超表面非线性折射和非线性吸收系数符号和大小的调控,并在x偏振入射条件下观察到最大~1.97 THz的蓝移.研究结果表明,该ENZ复合超表面可为发展高集成微纳光电器件提供材料平台,并可为微纳尺度下光场高效调控提供超快全光手段.Epsilon-near-zero(ENZ) hybrid metasurface is a kind of superstructure composed of ENZ materials and metal nanostructures,which has attracted much attention due to the enhanced interaction between light and matter.Here,a nonlinear metasurface based on indium tin oxide(ITO) films and metal nanostructures has been designed and fabricated.The broadband polarization-dependent nonlinear optical response characteristics of the hybrid metasurface have been investigated experimentally.Compared with the pure ITO film,the nonlinear absorption coefficient and nonlinear refractive index of the ENZ-based metasurface can be enhanced by 2 orders of magnitude,and the third-harmonic generation can also be effectively enhanced.By changing the polarization state of the incident light,the sign and magnitude of the nonlinear refraction and nonlinear absorption coefficient of the ENZ-based metasurface can be manipulated.The maximum blue shift of ~1.97 THz can be observed under the x-polarization incident condition.The results show that the ENZ-based metasurface can provide a new material platform for the development of highly integrated micro/nano optoelectronic devices,and may provide ultrafast all-optical methods for the efficient control of light field at micro/nano scale.

关 键 词：非线性光学 超材料 介电常数近零介质 非线性吸收 非线性折射 三次谐波产生 

分 类 号：O437[机械工程—光学工程]