基于法布里-珀罗腔的纳米环滤光器  

Nanoring color filters based on Fabry-Prot cavities

作　　者：吕江涛[1] 王凤文[1] 马振鹤[1] 司光远[1] 

机构地区：[1]东北大学秦皇岛分校控制工程学院,秦皇岛066004

出　　处：《物理学报》2013年第5期451-456,共6页Acta Physica Sinica

基　　金：国家自然科学基金批准号资助的课题~~

摘　　要：同轴纳米环结构由于具有特殊的光学特性,近年来引起了科学界的广泛关注.本文将重点研究在以纳米环形结构为基础的法布里-珀罗腔中所存在的两种形式的表面等离子共振,平面型和传输型.通过使用固定圆环阵列的周期而只改变圆环孔径大小的方法来实现调节传输型共振并达到滤波的效果.同时,控制圆环阵列的周期使其足够大,从而使得平面型共振峰位于近红外波段,以避免对处于可见光波段的传输型共振模式形成干扰,最终实现滤光效果.在实验中,通过使用周期固定为1200nm而孔径大小从10到180nm(以10nm递增)的同轴圆环结构,实现了把一束宽带的白光源分成不同颜色的单色光.实验结果表明,该方法解决了天线凹槽和一维层堆光栅型滤光器都普遍存在的偏振敏感性问题,使得类似滤光器件的应用范围更广,更能适应非偏振的自然光.通过有限时域差分法分析得到的理论计算结果和实验结果相匹配,实验现象得到了很好的理论支持和解释.Coaxial nanoring structures have attracted extensive attention in recent years due to their peculiar optical properties. In this article, we investigate two different types of resonances in plasmonic Fabry-Prrot cavities, planar surface plasmon and propagating surface plasmon. Using nanoring arrays with the same periodicity and different gaps, we can tune propagating surface plasmons and finally filter individual colors out. With large periodicities, planar surface plasmon resonance can be fixed in the near infrared range to avoid any disturbance on propagating surface plasmon resonance which is located in visible frequencies. In this work, we filter a broadband white source into different colors by using nanoring arrays with a fixed periodicity of 1200 nm and varying gaps range from 10 nm to 180 nm （in steps of 10 nm）. Compared with one-dimensional nanoslits or metal-insulator-metal （MIM） nanogratings, nanoring structures present polarization independence to the incident light, leading to more functional devices and broader applications （applicable to natural light, for instance）. Finite-difference time-domain （FDTD） simulations accord well with measurements, which confirms our conclusions and supports our explanations.

关 键 词：表面等离子体 同轴圆环纳米腔 透射型滤光器 

分 类 号：O482.3[理学—固体物理] TN25[理学—物理]