Excitation of surface plasmons in subwavelength nanoaperatures with different geometries

In this work, we investigate the transmission of light through an isolated subwavelength hole, the hole chain and the hole array with different geometries, respectively. It is shown that that when the light illuminates an isolated subwavelength hole, localized surface plasmons (LSPs) are excited and contribute to transmission of the hole; while the light illuminates the hole chain and array, both LSPs and propagating surface plasmons (PSPs) are excited, and their contributions to the transmission of holes strongly depend on the geometry of the hole chain and array, and also on the polarization of incident light. The theoretical calculations are based on three-dimensional full-vector finite-difference time-domain method. The investigations may have potential applications on designing plasmonic structures and devices.