Characteristics of propagation of light beams in gyrotropic crystals

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 5, pp. 815–819, May, 1991.     

Nonexponentially Decaying Electromagnetic Waves Localized at the Boundary of Anisotropic Metal–Dielectric Structures

The possibility of the existence of a special class of surface electromagnetic waves with amplitude decreasing nonexponentially as they pass into an anisotropic metal–dielectric structure that borders the isotropic dielectric has been shown. The dispersion equation describing the propagation of such special surface waves has been obtained, and their attenuation coefficients and formula for electric and magnetic fields in contacting media have also been found. The expressions for the longitudinal and transverse components of the Poynting vector and volume density of electric and magnetic energy of special surface waves have been obtained. Numerical calculations for the layered metal–dielectric nanostructure that is described by a uniaxial tensor of effective dielectric permeability have been carried out Decaying.     

Propagation and transformation of light waves in magnetically active periodic structures

The influence of an external magnetic field applied to a magnetoactive periodic structure on the specific features of formation of the photonic band gaps is established. It is shown that abrupt (stepwise) changes in the polarization of the radiation transmitted by the periodic structure and reflected from it exist near the band gap edges. The possibility of a substantial enhancement of the Faraday effect at a low level of optical losses in the magnetoactive periodic structure with a large number of periods and a dielectric contrast and without a defect layer is substantiated.     

Enhancement of the Faraday rotation in magnetically active periodic structures with defects

Relations that determine the field of a light wave transmitted through and reflected from a periodic structure lying on a substrate and containing a defect layer are derived for the case of an arbitrary symmetry of both the defect layer and the layers forming the structure. Exact expressions are obtained for the determination of the positions of the defect modes. The feasibility of a considerable enhancement of the Faraday rotation while retaining 100% transmission through the defect-containing magnetically active structure at a high dielectric contrast is revealed. It is shown that the angle of magnetooptical rotation of the polarization plane in a periodic structure is a bounded quantity.     

Femtosecond Bessel light pulse formation by a multi-circular diaphragm

The dynamics of the envelope of a new type of light field, a femtosecond Bessel light pulse (FBLP) formed from a Gaussian pulsed beam by means of a multi-circular diaphragm, has been investigated theoretically. It is shown that the FBLP possesses a steady structure that features a narrow central maximum and significantly suppressed subordinate maxima.     

Formation of Bessel light pulses by means of a conical mirror

The feasibility of forming diffractionless Bessel light pulses by means of a conical mirror is demonstrated. The dependence of the spatial-temporal and energy characteristics of these pulses on the mirror parameters is examined.     

Specific features of light propagation in a periodic structure with regular arrangement of defect layers

Specific features of light propagation in a periodic structure with a large number of identical regularly arranged defect layers are considered. Rigorous analytical formulas for the transmittance and reflectance of the structures are derived. It is shown that the presence of periodically arranged inclusions may give rise to new photonic band gaps, with their positions controlled by the dielectric properties and thickness of the defect layers.     

Enhancement of the Faraday effect in finite three-layer periodic media

It is shown that the inclusion of a magnetoactive defect layer in the center of a finite dielectric three-layer periodic medium allows one to obtain several spectral regions between the photonic band gaps, in which significant enhancement of the Faraday effect is realized in the almost complete absence of diffraction losses. These results can be used for creating and optimizing the parameters of miniature high-performance nonreciprocal elements, combining (i) the possibility of achieving considerable magneto-optical rotation of the plane of polarization at distances of about a few microns and (ii) low optical losses.