Realization of an extraordinary transmission window for a seamless Ag film based on metal-insulator-metal structures

A polarization-sensitive, wide-angle operating antireflection coating based on a metal-insulator-metal structure is investigated. In both visible and near-infrared regions, it dramatically reduces the reflection and enhances the transmission through a seamless Ag film near a specifically designed frequency due to the surface plasmon resonance. By achieving above 70% transmission through a 20 nm-thickness Ag film theoretically, this antireflection coating is able to open an extraordinary transmission window for a metallic layer without any slits or holes.