In this seed project, theoretical simulations were carried out to investigate the extraordinary optical transmission (EOT) in the visible and infrared regions. One of the EOT manifestation is that the fraction of light transmitted through a periodic array of subwavelength holes perforated in a metallic film exceeds the open fraction occupied by the holes at certain wavelengths related to the periodicity of the hole array, and the observed transmission can be anomalously large as compared to well established predictions for isolated holes. The goal of our computer simulations is to find out the ideal parameters for the desired transmission spectrum of the nanostructures. It could lead to a better design of the metallic nanostructure plasmonic devices. The goal of the project is to design, develop and integrate metallic nanostructure photonics devices, which are capable of routing and manipulating light. These metallic nanostructures have potential applications in optical communication, infrared filters, optical spectroscopy, THz imaging, biosensors, and etc.
We performed simulations of the metallic structures, which are a small open (square or circle) with a period structure. Finite-difference time-domain (FDTD) method with MEEP software and finite element method (FEM) with COMSOL software are applied in simulations. The calculated results as a function of the diameters of the hole, the periodicities of the hole array, and the thicknesses of the metal film are compared with the reflection and transmission experimental spectrum that we measured. We also performed calculation and will measure the reflection and transmission spectrum as a function of the incident angles and polarizations.