Zhang Peng, Zhao Ming, Wu Lin, Zheng Yu, Duan Jian, Yang ZhenYu
J Opt Soc Am A Opt Image Sci Vis. 2013 Nov 1;30(11):2356-60. doi: 10.1364/JOSAA.30.002356.
We studied numerically the transmission properties of the periodic array of asymmetric cross-shaped apertures in an Ag film. The relative positions of the two orthogonally oriented rectangular apertures are varied, rather than their length or width. Each transmission peak of the original symmetric cross-shaped apertures will split into two peaks in the case of the asymmetric cross-shaped apertures when the electric field is perpendicular to the long axis of the unchanged rectangular aperture. The wavelength of the shift peak has a linear relation with the asymmetry. This resonance response mainly results from the excitation of the trapped mode provided by the structural symmetry breaking. A distribution of the magnetic field and a simple Lagrange model are used to interpret these phenomena. In addition, the intensity of the transmission peaks can be tuned by changing the incident polarization angle.
我们对银膜中不对称十字形孔径的周期性阵列的传输特性进行了数值研究。两个正交取向的矩形孔径的相对位置发生变化，而不是它们的长度或宽度。当电场垂直于未改变的矩形孔径的长轴时，在不对称十字形孔径的情况下，原始对称十字形孔径的每个传输峰将分裂为两个峰。位移峰的波长与不对称性呈线性关系。这种共振响应主要源于结构对称性破坏所提供的俘获模式的激发。利用磁场分布和一个简单的拉格朗日模型来解释这些现象。此外，通过改变入射偏振角可以调节传输峰的强度。
