Nonlinear Dynamics of Parametric Oscillations of Polaritons in a Microcavity

Optics and Spectroscopy - The dynamics of polaritons in a microcavity in the parametric oscillator mode, when two pump polaritons turn into the signal and idler polaritons and vice versa, has been...     

Optical properties of semiconductors under strong pumping in the <Emphasis Type="Italic">M</Emphasis>-band region and two-photon probing of the biexciton state

The behavior of the semiconductor dielectric susceptibility under the action of a strong laser pulse in the range of the luminescent M band and two-photon probe of a biexciton level is investigated. It is shown that the pronounced Autler-Towns effect occurs at the two-photon transition. The position of the absorption peaks is essentially determined by the amplitude and frequency of the pump field.     

Cavityless optical bistability in a thin semiconductor film upon the resonant excitation of excitons and biexcitons

The bistable properties of a thin semiconductor film under conditions of resonant excitation of coherent excitons and biexcitons by photons in one or two different pulses are studied theoretically. Fiz. Tverd. Tela (St. Petersburg) 40, 932–933 (May 1998)     

Radiative recombination of excitons in semiconductors at high excitation intensities

The shape of the exciton luminescence band of the gaseous phase of free excitons in crystal Si is investigated under high level excitation. Only the exciton-exciton interaction is considered and the influence of collisions of excitons with phonons and electrons is not taken into account. The theoretical shape of the exciton luminescence band qualitatively agrees with experiment. The process of the radiative Auger-recombination of two indirect excitons without the participation of phonons is studied in Ge and Si. The expression for the frequency and temperature dependence of the probability of radiation is obtained. The band has the asymmetrical Gaussian form with the steep short-wave tail. The predicted luminescence band in Ge is shifted at the long-wavelength side from the well-known exciton luminescence bands with participation of the phonons. The selection rules for the probability amplitude of the process under consideration are obtained.     

Optical nutation in the exciton range of spectrum

Optical nutation in the exciton range of spectrum is studied in the mean field approximation taking into account exciton-photon and elastic exciton-exciton interactions. It is shown that the features of nutation development are determined by the initial exciton and photon densities, the resonance detuning, the nonlinearity parameter, and the initial phase difference. For nonzero initial exciton and photon concentrations, three regimes of temporal evolution of excitons and photons exist: periodic conversion of excitons to photons and vice versa, aperiodic conversion of photons to excitons, and the rest regime. In the rest regime, the initial exciton and photon densities are nonzero and do not change with time. The oscillation amplitudes and periods of particle densities determined by the system parameters are found. The exciton self-trapping and photon trapping appearing in the system at threshold values of the nonlinearity parameter were predicted. As this parameter increases, the oscillation amplitudes of the exciton and photon densities sharply change at the critical value of the nonlinearity parameter. These two phenomena are shown to be caused by the elastic exciton-exciton interaction, resulting in the dynamic concentration shift of the exciton level.     

Nonlinear asymmetric waves induced in a symmetrical three-layer structure by the generation of excitons and biexcitons in semiconductors

A theory of asymmetric TE-polarized quasi-surface waves propagating inside a symmetrical planar three-layer structure with a linear core and nonlinear plates is developed. The nonlinearity of the plates is associated with the inclusion of the optical exciton-biexciton conversion. The dispersion laws of the propagating waves are derived and investigated.     

Transmission of phase-modulated laser light through a thin semiconductor film in the excitonic spectral range and an optical analog of the feshbach effect

A theoretical and numerical analysis of the transmission of phase-modulated laser pulses through a thin film with excitonic nonlinearity is performed. It is shown that, by choosing the modulation law, one can efficiently control the optical nonlinearity of the film down to the inversion of the sign of nonlinearity.     

The Exciton–Polariton Dispersion Law under the Action of Strong Pumping in the Region of the <Emphasis Type="Italic">M</Emphasis>-Band of Luminescence

The double-pulse interaction with excitons and biexcitons in semiconductors is studied theoretically. It is shown that the dispersion law of carrier wave has three branches under the action of a powerful pumping in the region of the M-band of luminescence. Values of parameters at which the dispersion law branches can intersect due to the degeneration of the exciton level energy have been found. The effect of a significant change in the force of coupling between the exciton and photon of a weak pulse with a change in the pumping intensity is predicted.     

Polariton-Type Dispersion Laws for Three-Level Atoms Interacting with Two Laser Radiation Pulses

Journal of Experimental and Theoretical Physics - Behavioral features of polariton dispersion laws are studied for three-level atoms interacting with two coherent laser radiation pulses with...     

Exciton susceptibility of semiconductors at high laser-excitation levels

The hysteresis behavior of the real and imaginary parts of the susceptibility of a semiconductor in the exciton region of the spectrum is investigated with consideration of the exciton-phonon and elastic exciton-exciton interactions in the pump-probe regime as a function of the intensity and frequency of the strong laser pulse and the frequency of the probe pulse. The conditions for the appearance of suppression of the damping and amplification of the probe pulse are determined. Abrupt red and blue shifts of the spectral position of the exciton absorption band as a function of the pump pulse intensity are predicted. Fiz. Tverd. Tela (St. Petersburg) 40, 934–935 (May 1998)