Controlling surface plasmons on metallodielectric photonic crystals

Summary form only given. Any metal surface will support surface plasmons, or surface waves. These are waves that are evanescent in both the metal and the air, and are confined to the interface between the two media. They cannot propagate into the conductive metal, yet they cannot escape into the air due to total internal reflection. Surface modes occur over a broad range of frequencies spanning from DC up to a cutoff frequency, usually in the ultraviolet. They play an unfortunate role at microwave frequencies, where they can cause unwanted losses in antennas, due to radiation along the surface of the metal ground plane. However, it is possible to create bandgaps in the surface modes using the principles of photonic crystals. This has already been demonstrated at optical frequencies using corrugated silver films. With the advent of wide bandgap, metallodielectric photonic crystals, it is possible to engineer the surface, and eliminate the surface modes over a range of microwave frequencies. In effect, the photonic crystal serves as an artificial metal, capable of filling the role of an antenna ground plane, without the unwanted surface modes.