One Dimensional Metallic Photonic Crystal

For the strong dispersion and negative s from visible to infrared range of metal, Surface Plasmon Polaritons (SPP) mode which are decayed in both mediums are supported by the interface of metal and dielectric material. By altering the structure of a metal's surface, the properties of SPP-in particular their interaction with light-can be tailored, which offers the potential for developing new types of photonic device. SPP are being explored in subwavelength optics, data storage, light generation and microscopy. In this paper, we study the dispersive and transmission phenomena of different structures: metal film,1D photonic crystals (multilayer film structure ) and metallic grating in the visible to infrared range, analyze the relationship between the optical properties and the structure. In visible to infrared range, the decay lengths in the metal is about 20nm.Metal film structure: There is SPP mode in both upper surface and lower one. when the depth of the film is less than 4 times of the decay lengths from the metal, eigen frequency would split to be upper and lower because of the coupling surface plasmon polaritons on both of the film. The degree of the splitting is decayed exponentially as the grating depth increasing. All the phenomena give good candidates for choosing the metal depth of the metal photonic crystals.1D photonic crystals multilayer films structure: In the low frequency range, there are TM modes but no mode for TE. The breadth of the stopping bands should increase as the depth of metal layer increases. When the depth of the metal layer is more than 5 times of the decay length, the band widths shall disappear.Metallic grating structure: Energy structure shows that there are SPP bandgaps on the edge of the band, and there are flat bands of low frequency when the depth of the grating is larger than half of the grating period. Transmission properties show that with very narrow and deep enough slits the grating can exhibit enhance transmission for wavelengths larger than the period of the grating. There are two possible ways of transferring light from the upper surface to the lower one: by the excitation of coupled surface plasmon polaritons on both surfaces of the metallic grating or by F-P resonances located in the slits. There are no enhanced transmission phenomena of TE mode, because TE mode can't support SPP mode and there are no transmitting waves in the slits of the grating.