Showing papers by "Alexey Kavokin published in 2000"
TL;DR: Experimental data on the RRS from multiple QWs show the predicted strong temporal oscillations at small scattering angles, which are well explained by the presented theory.
Abstract: A theoretical concept of resonant Rayleigh scattering (RRS) of exciton-polaritons in multiple quantum wells (QWs) is presented. The optical coupling between excitons in different QWs can strongly affect the RRS dynamics, giving rise to characteristic temporal oscillations on a picosecond scale. Bragg and anti-Bragg arranged QW structures with the same excitonic parameters are predicted to have drastically different RRS spectra. Experimental data on the RRS from multiple QWs show the predicted strong temporal oscillations at small scattering angles, which are well explained by the presented theory.
35 citations
TL;DR: In this article, the selfconsistent procedure of solving both the Schrodinger and Poisson equations for electron and hole wave functions has been combined with the variational calculation of exciton states in strained GaN/AlxGa1−xN quantum wells.
Abstract: The self-consistent procedure of solving both the Schrodinger and Poisson equations for electron and hole wave functions has been combined with the variational calculation of exciton states in strained GaN/AlxGa1−xN quantum wells. The procedure accounted properly for the free-carrier effects on the excitonic wave function, namely, the exciton bleaching and the quantum exclusion effects. It also allowed us to quantify the dependence of the exciton energy and of the oscillator strength on the optical pumping density. The calculation revealed an interesting interplay between the screening of the polarization fields, which leads to the increase of the electron-hole overlap, and the screening of the electron-hole interaction, which affects the exciton Bohr radius. The peculiar nonmonotonic behavior of the exciton binding energy as a function of the density of the electron-hole plasma results from these combined effects.
23 citations
TL;DR: In this article, the effects of nonradiative damping of the exciton resonance in the quantum wire on the optical response of the microcavity structure have been analyzed.
Abstract: Exciton-light coupling in cylindrical microcavities containing quantum wires has been treated by means of classical electrodynamics within the nonlocal dielectric response model. A typical anticrossing behavior of quasi-one-dimensional exciton-polariton modes has been obtained, as well as the weak-coupling--strong-coupling threshold. Effects of the nonradiative damping of the exciton resonance in the quantum wire on the optical response of the microcavity structure have been analyzed.
16 citations
TL;DR: In this article, a numerical simulation of time-resolved light reflection from GaN/AlGaN single and multiquantum wells (MQWs) revealed a pronounced vertical motional narrowing effect.
Abstract: Numerical simulation of time-resolved light reflection from GaN/AlGaN single and multiquantum wells (MQWs) revealed a pronounced vertical motional narrowing effect. This effect consists in reduction of the inhomogeneous broadening of the exciton peaks and increase of the decay time of the time-resolved reflection due to the averaging of the vertical disorder in the structure by extended exciton-polariton modes. The theory predicts pronounced oscillations in the time-resolved reflection of MQWs resulting from the interference of exciton-polariton modes in the structure.
6 citations
TL;DR: In this paper, it was shown that disorder-induced scattering of light between bright and dark exciton-polariton modes governs the coherent optical response of GaN/AlGaN quantum wells (QWs) on a femtosecond scale.
Abstract: We show theoretically that disorder-induced scattering of light between « bright » and « dark » exciton-polariton modes governs the coherent optical response of GaN/AlGaN quantum wells (QWs) on a femtosecond scale. The incident light essentially excites the “bright” modes, they emit the most part of light radiatively during first few hundreds of femtoseconds. The rest of the coherent signal, i.e. the temporal behaviour on a scale from 1 to few picoseconds, comes from the “dark” modes, populated due to the elastic scattering processes in the system, and mixed so that they form two bulk-like polariton branches. The pico-second scale optical response of GaN/AlGaN QWs is essentially incoherent because of a very efficient scattering of exciton-polaritons by a structural disorder.