Nonlinear Terahertz Emission in Semiconductor Microcavities

We consider the nonlinear terahertz emission by the system of cavity polaritons in the regime of polariton lasing. To account for the quantum nature of terahertz-polariton coupling we use the Lindblad master equation approach and demonstrate that quantum microcavities reveal rich variety of the nonlinear phenomena in terahertz range, including bistability, short THz pulse generation and THz switching.Comment: 4 pages + 5 figures + Supplementary Material. (Final version containing the derivation of the kinetic equations.

Rashba plasmon polaritons in semiconductor heterostructures

We propose a concept of surface plasmon-polariton amplification in the structure comprising interface between dielectric, metal and asymmetric quantum well. Due to the Rashba spin-orbit interaction, mimina of dispersion relation for electrons in conduction band are shifted with respect to the maximum of dispersion dependence for holes in $\Gamma$-point. When energy and momentum intervals between extrema in dispersion relations of electrons and holes match dispersion relation of plasmons, indirect radiative transition can amplify the plasmons; excitation of leaky modes is forbidden due to the selection rules. Efficiency of the indirect radiative transition is calculated and design of the structure is analysed.Comment: Published (4 pages + 3 figures), 2nd proof versio

Analytical theory of light localization in one-dimensional disordered photonic crystals

Influence of the various types of disorder on propagation of light in one-dimensional periodic structures is studied analytically using statistical approach based on a Fokker–Planck type equation. It is shown that light localization length behaves non-monotonically as a function of disorder amplitude in all the examined models except for purely geometric disorder. This feature is explained by crossover between weak disorder regime corresponding to gradual destruction of the reflecting properties of a photonic crystal and strong disorder regime, when periodic component of the refractive index can be treated as a perturbation. The region of small disorder is shown to be universal provided that a disorder parameter is properly introduced

Gap solitons in quasiperiodic optical lattices

Families of solitons in one- and two-dimensional (1D and 2D) Gross-Pitaevskii equations with the repulsive nonlinearity and a potential of the quasicrystallic type are constructed (in the 2D case, the potential corresponds to a five-fold optical lattice). Stable 1D solitons in the weak potential are explicitly found in three bandgaps. These solitons are mobile, and they collide elastically. Many species of tightly bound 1D solitons are found in the strong potential, both stable and unstable (unstable ones transform themselves into asymmetric breathers). In the 2D model, families of both fundamental and vortical solitons are found and are shown to be stable.Comment: 8 pages, 11 figure

Bragg Polaritons: Strong Coupling and Amplification in an Unfolded Microcavity

Periodic incorporation of quantum wells inside a one--dimensional Bragg structure is shown to enhance coherent coupling of excitons to the electromagnetic Bloch waves. We demonstrate strong coupling of quantum well excitons to photonic crystal Bragg modes at the edge of the photonic bandgap, which gives rise to mixed Bragg polariton eigenstates. The resulting Bragg polariton branches are in good agreement with the theory and allow demonstration of Bragg polariton parametric amplification.Comment: 4 pages, 4 figure

Stability of the photonic band gap in the presence of disorder

The photonic eigenmodes near a band gap of a type of one-dimensional disordered photonic crystal have been investigated statistically. For the system considered, it is found that the tail of the density of states entering the band gap is characterized by a certain penetration depth, which is proportional to the disorder parameter. A quantitative relation between the relative penetration depth, the relative width of the photonic band gap, and the disorder has been found. It is apparent that there is a certain level of disorder below which the probability of the appearance of photonic eigenstates at the center of the photonic band gap essentially vanishes. Below the threshold, the ensemble-averaged transmission at the center of the photonic band gap does not change significantly with increasing disorder, but above threshold it increases much more rapidly. A simple empirical formula has been obtained which describes how the logarithm of the transmission relates to the periodic refractive index modulation and the disorde