Reflectance controlling based on surface plasmon polaritons stimulated over the surface of metallic nanostructures

摘要

The surface plasmon polaritons (SPPs) is an electromagnetic wave that can be stimulated and then propagates over the surface of the preshaped metallic nanostructures or the interface between the surface of the metallic nanostructures and the substrate media due to a strong coupling of incident light and the surface free-electrons moving on the metallic nanostructure surface with a featured micrometer scale. As shown, through SPPs, incident light energy can be localized effectively in a sub-wavelength region or space, and thus so-called light diffraction limit can be break through easily. Therefore, it has demonstrated a good prospects for developing advanced functioned materials or devices such as light absorbing materials, optical antennas, and optical information storage modules. In this paper, we propose a special metallic nanostructures, which can be used to absorb a certain band of incident light by converting them into a kind of local free-electron oscillation, which means that SPPs can be generated and processed efficiently. As shown, the metallic nanostructures will present a lower reflectivity in the wavelength range, and through adjusting several key parameters such as the period of the metallic nanostructures, we can achieve an effective control of reflectivity because a valley of the reflectivity curve can be formed, which means a low reflectance at a specific wavelength band has been obtained.