H型金属孔阵列结构强透射折射率传感特性研究

Refractive Index Sensing Property of Extraordinary Transmission with H-shaped Metal Hole Array

摘要:

提出了一种H型金属孔阵列结构,利用该结构形成的法布里-珀罗腔加强表面等离激元耦合作用,以期获得较好的强透射现象。采用有限时域差分法(FDTD)对该结构进行数值仿真,并详细研究了H型金属孔阵列中水平方向矩形孔和竖直方向的两相同对称矩形孔的长和宽等参数对强透射特性的影响;同时研究了基于该现象的折射率传感特性。结果表明:当水平方向矩形孔的长和宽分别为300和120nm、竖直方向的两相同对称矩形孔的长和宽分别为60和10nm时,强透射现象较好,并在此基础上获得了389RIU/nm的折射率灵敏度。这些研究结果有望为高性能微纳等离子体传感器的设计提供理论参考。

Abstract:

In this paper, a H-shaped metal hole array structure was proposed, then it was used to form the Fabry-Perot cavity to enhance the surface plasmon polarizations (SPP) coupling effect, hoping to obtain a better optical transmission phenomenon. H-shaped hole array consists of a vertical rectangular hole and two horizontal symmetrical rectangular holes, thus the effects of parameters of the holes, such as the length and the width, on the transmission characteristics were studied in detail by using the finite-difference time-domain (FDTD) method. Meanwhile, the refractive index sensing property was investigated based on the phenomenon. It is found that when the length and the width of the vertical rectangle holes are 300 and 120nm, and the length of the two symmetric rectangular holes in the horizontal direction are 60 and 10nm respectively, a strong transmission phenomenon can be realized. And the sensitivity of the refractive index can reach 389RIU/nm.