N. V. Rudakova

Polarization-preserving anisotropic mirror on the basis of metal–dielectric nanocomposite

The model of a polarization-preserving anisotropic mirror is proposed. The mirror is a plane boundary of a metal–dielectric nanocomposite that consists of silver spheroidal nanoparticles dispersed in a transparent matrix. The dependence of reflection spectra on the shape of the nanoparticles is studied. It is shown that in one region of the spectrum, the mirror preserves the sign of polarization in the reflected light.

Band structure of a two-dimensional resonant photonic crystal

The band structure of two-dimensional resonant photonic crystals of two types has been calculated using the expansion of eigenfunctions in plane waves. Crystals of one type consist of infinite dielectric cylinders forming a square lattice filled with a resonant gas, and crystals of the other type consist of infinite cylindrical holes filled with a resonant gas and forming a square lattice in a dielectric matrix. It has been shown that, in both cases, the dispersion of a resonant gas in combination with the dispersion of a two-dimensional structure with a photonic band gap leads to the appearance of an additional narrow transmission band near the edge of the band gap or an additional band gap in the continuous spectrum of the photonic crystal. The calculations performed have demonstrated that new dispersion properties substantially depend on the density of the resonant gas, the position of the resonant frequency with respect to the edge of the band gap, and the direction of propagation of electromagnetic waves.

Spectral properties of a two-dimensional resonant metal-dielectric photonic crystal

We have studied the transmission spectra of resonant two-dimensional photonic crystals of two types, one of which consists of nanocomposite cylinders that form a square lattice in vacuum and the other of which consists of cylindrical holes that form a square lattice in nanocomposite matrix. The nanocomposite consists of metallic nanospheres that are dispersed in a transparent matrix and is characterized by an effective resonant dielectric permittivity. We show that, depending on the position of the resonant frequency of the nanocomposite with respect to the boundaries of the band gap, there arises either an additional transmission band in the transmission spectrum in the band gap or an additional band gap in the continuous spectrum of the photonic crystal. As the structural and geometric parameters of the system change, both the additional transmission band and the additional band gap are considerably modified. We analyze particular features of the spatial distribution of the electromagnetic field intensity in crystals. The considered effects can be used to extend the possibilities of creating new photonic crystals with specified properties.

Transmission of light through a plane-parallel plate of a two-dimensional resonant photonic crystal

The transmission spectra of two-dimensional resonant photonic crystals of two types have been investigated. Crystals of one type consist of dielectric cylinders forming a square lattice filled by a resonant gas with mercury atoms, and crystals of the other type consist of cylindrical holes filled with a gas and forming a square lattice in a dielectric matrix. It has been established that characteristics of the spectrum of additional transmission arising in the band gap of the photonic crystal can be changed significantly by varying the gas pressure and the angle of incidence. It has been demonstrated that the calculated features in the transmission spectrum of the photonic crystal are stable with respect to a significant increase in the width of the atomic resonance.

Optical properties of nanostructured 2D metal-dielectric photonic crystals with a lattice defect

Optical properties of 2D nanocomposite-based photonic crystals with a lattice defect are studied. The nanocomposite comprises metallic nanospheres dispersed in a transparent matrix and is characterized by an effective resonant permittivity. Transmission spectrum for s-polarized waves at oblique incidence is calculated. Spectral manifestation of the splitting of the defect mode when its frequency coincides with the resonant frequency of the nanocomposite is studied. The essential dependence of the splitting on the angle of incidence and concentration of metallic nanospheres in the nanocomposite matrix is established. Specific features of spatial distribution of the electric field intensity in defect modes of crystals are analyzed.

Features of a two-dimensional photonic crystal filled with resonance gas

The band structure has been calculated for a two-dimensional photonic crystal consisting of infinite cylindrical openings filled with a resonance gas and forming a square lattice in a dielectric matrix. An additional narrow transmission band close to the edge of the band gap has been detected, along with an additional band gap in the continuous spectrum of the photonic crystal. The novel dispersion properties substantially depend on the fraction of resonance gas in the photonic crystal, as well as on the density of the resonance gas and the position of the resonance frequency relative to the edge of the band gap.