Two-dimensional photonic crystals with a lattice defect: Spectrum of defect modes, localization of light, and formation of evanescent waves

Properties of an electromagnetic field localized in the defect modes of two -dimensional photonic crystals are studied. The defect-mode spectrum of the se structures is calculated, electromagnetic field localization and channel ing effects are analyzed, and the properties of the field inside and beyond a photonic crystal with a lattice defect are also studied. The calculation s show that the electromagnetic field is localized in the defect mode of a photonic crystal in a region smaller than the wavelength. The dependence of the defect-mode spectrum on the parameters of the photonic crystal is inve stigated and possibilities for controlling the spectrum of defect modes are indicated. It is shown that the optical field leaving a photonic crystal p ossesses the properties of a evanescent wave, which means that spatial reso lution substantially greater than the wavelength of the radiation can be ac hieved in the near field and opens up possibilities for using photonic crys tals with a lattice defect in near-field optical microscopy. The possibilit y of externally controlling an optical field localized in the defect modes of a photonic crystals is demonstrated. (C) 2000 MAIK "Nauka/Interperiodica ".