Focusing Systems Based on Two-Dimensional Photonic Crystals

Methods of focusing electromagnetic waves based on the use of two-dimensional photonic crystals formed by metal and dielectric elements are considered. In the first case, the physical basis for creating radiation focusing systems consists in the use of the properties of a homogeneous medium with ultralow refractive index values demonstrated by metallic photonic crystals at frequencies of the first allowed zone. In the second case, the constructive interference of directly propagating waves and edge waves diffracting at the edges of spatially bounded dielectric structures is used for focusing.