ABSTRACT
Electromagnetic crystals are artificial periodical structures operating at frequencies where the wavelength is comparable with the characteristic period of the structure. In the optical frequency range, such structures are called photonic crystals. Photonic and electromagnetic crystals found numerous applications, for example, in frequency-selective devices, and as waveguide and resonator components, both in the optical and microwave frequency ranges. The backward-wave effects and negative refraction in structures with isotropic morphology are considered as unique features of materials that have simultaneously negative permittivity and permeability. The all-angle negative refraction in a medium of perhaps discrete but isotropic morphology offers the unique tool to obtain the aberrationless high-quality optical images in flat layers. The all-angle negative refraction phenomenon is observed in photonic crystals at frequencies close to the bandgap edges. The chapter discusses the possibility to obtain the subwavelength sizes of the image of a point source in flat photonic crystal layers.
