arXiv subjects

M. M. Voronov

Publications and source records attributed to M. M. Voronov.

7 recordsLinked to original sources

arXiv2020

Intense Anti-Stokes Emission of Erbium Ions in Gallium Lanthanum Sulphide-Oxide Glass in Visible Spectral Range

Photoluminescence spectra have been investigated in erbium doped GaLaS(O) glasses. The samples demonstrate intense green emission bands centered at around 525 and 550 nm due to up-conversion processes in erbium ions. The theoretical description of up-conversion intensity as a function of excitation intensity has been offered. It is based on a solution of a system of rate equations taking into account three up-conversion transitions.

physics.optics↗

arXiv2013

Diffraction anomalies in hybrid structures based on chalcogenide-coated opal photonic crystals

The results of spectroscopic studies of the diffraction anomalies (the so-called resonant Wood anomalies) in spatially-periodic hybrid structures based on halcogenide (GST225)-coated opal films of various thickness are presented. A theoretical analysis of spectral-angular dependencies of the Wood anomalies has been made by means of a phenomenological approach using the concept of the effective refractive index of waveguiding surface layer.

physics.optics↗

arXiv2010

Resonant photonic crystals and quasicrystals based on highly doped quantum-well structures

A theory of light propagation through one-dimensional photonic crystals and deterministic aperiodic structures, including quasicrystals, based on doped quantum-well structures has been developed. The resonant Bragg condition, leading to the superradiant regime and formation of the widest optical reflection spectrum, has been formulated. The expressions for band gap edges for light waves in the Bragg structures have been obtained. The reflection and absorption spectra of such systems are calculated. The optical properties of the doped multiple-quantum-well structure are compared with the properties of undoped ones.

cond-mat.mes-hall↗

arXiv2009

Resonant Photonic Quasicrystalline and Aperiodic Structures

We have theoretically studied propagation of exciton-polaritons in deterministic aperiodic multiple-quantum-well structures, particularly, in the Fibonacci and Thue-Morse chains. The attention is concentrated on the structures tuned to the resonant Bragg condition with two-dimensional quantum-well exciton. The superradiant or photonic-quasicrystal regimes are realized in these structures depending on the number of the wells. The developed theory based on the two-wave approximation allows one to describe analytically the exact transfer-matrix computations for transmittance and reflectance spectra in the whole frequency range except for a narrow region near the exciton resonance. In this region the optical spectra and the exciton-polariton dispersion demonstrate scaling invariance and self-similarity which can be interpreted in terms of the ``band-edge'' cycle of the trace map, in the case of Fibonacci structures, and in terms of zero reflection frequencies, in the case of Thue-Morse structures.

cond-mat.mes-hall↗

arXiv2007

Resonant Fibonacci Quantum Well Structures

We propose a resonant one-dimensional quasicrystal, namely, a multiple quantum well (MQW) structure satisfying the Fibonacci-chain rule with the golden ratio between the long and short inter-well distances. The resonant Bragg condition is generalized from the periodic to Fibonacci MQWs. A dispersion equation for exciton-polaritons is derived in the two-wave approximation, the effective allowed and forbidden bands are found. The reflection spectra from the proposed structures are calculated as a function of the well number and detuning from the Bragg condition.

cond-mat.mes-hall↗

arXiv2007

Exciton luminescence in resonant photonic crystals

A phenomenological theory of luminescence properties of one-dimensional resonant photonic crystals is developed within the framework of classical Maxwell equations with fluctuating polarization terms representing non-coherent sources of emission. The theory is based on an effective general approach to determining linear response of these structures and takes into account formation of polariton modes due to coherent radiative coupling between their constituting elements. The general results are applied to Bragg multiple-quantum-well structures, and theoretical luminescence spectra of these systems are compared with experimental results. It is shown that the emission of such systems can be significantly influenced by deliberately introducing defect elements in the structure. The relation between absorption and luminescence spectra is also discussed.

cond-mat.mes-hall↗

arXiv2006

Special frequencies in reflection spectra of Bragg multiple quantum well structures

We have studied theoretically optical reflection spectra from the Bragg multiple quantum well structures. We give an analytical explanation of the presence of two special frequencies in the spectra at which the reflection coefficient weakly depends on the quantum well number. The influence of the exciton nonradiative damping on the reflection spectra has been analyzed. It has been shown that allowance for the dielectric contrast gives rise to the third special frequency at which the contributions to the reflectivity related to the dielectric contrast and the exciton resonance mutually compensate one another.

cond-mat.mes-hall↗