环形凹槽结构借助金属圆盘和金属锥尖实现增强聚束效应  

Realization of Enhanced Light Directional Beaming Via a Concentric Ring Structure Composited with Circular Disk and Conical Tip

作　　者：张庆[1,2] 刘呈普[2] 

机构地区：[1]上海大学理学院,上海200444 [2]中国科学院上海光学精密机械研究所强场激光物理国家重点实验室,上海201800

出　　处：《纳米科技》2014年第6期13-18,共6页

基　　金：国家自然科学基金项目（Nn11374318）

摘　　要：基于传统“牛眼”结构对光波的聚束原理，介绍一种新颖的亚波长光聚束组合结构，在入射端的一定距离添加金属圆盘和出射端添加金属锥尖，实现聚柬能力的增强，FDTD仿真结果表明，基于金属圆盘和金属薄膜之间形成强烈共振的波导腔，使得远场光束中心能量增强 利用金属锥尖对出射光激发的表面等离激元进行局域和收集，抑制了远场光束的边锋，进一步增强了中心光束的能量，角分布变窄。该结构聚束作用和锥尖顶端局域场增强作用可广泛地应用于亚波长光学元器件设计、生物医疗探测等领域。Based on the light beaming theory of traditional bulFs eye structure, one new subwavelength structure with a metal circular disk added at the input side and a conical tip added at the output side, aiming to enhance beaming property is proposed. The FDTD simulation confirms that far-field intensity can be greatly enhanced due to the strong coupling between the circular disk and metal film forming a cavity-like antenna. The side peaks of far-field angular distribution has been suppressed by using the focusing and collecting effect from the conical tip significantly localizing the surface plasma, and thus light intensity was enhanced at zero degree. Consequently, an enhanced beaming efficiency with high intensity, small angle divergence and weak side peaks is obtained. And the structure with enhanced focusing effect and local field at the conical tip can be widely applied in the subwavelength optical elements, biomedical detection and other fields.

关 键 词：亚波长结构 表面等离子体 牛眼结构 聚束效率 

分 类 号：TN61[电子电信—电路与系统]