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We show that engineering the cavity aspect ratio of AlGaAs micropillar resonator allows for the two orders of magnitude increase in the efficiency of second harmonic generation at telecom wavelengths. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate theoretically that the interaction of quantum rings with a high-frequency off-resonant electromagnetic field (dressing field) substantially renormalizes their electronic properties. Particularly, it is shown that a linearly polarized dressing field decreases the spin splitting arisen from the Rashba spin-orbit interaction, whereas a circularly polarized field splits electron states corresponding to mutually opposite directions of angular momentum. As a consequence, the dressing field can serve as an effective tool to control spin and transport characteristics of the quantum rings and be potentially exploited in optoelectronic applications. [ABSTRACT FROM AUTHOR]

We present a theory to describe the interaction of electrons in gapped and gapless graphene with a strong off-resonant electromagnetic field (dressing field). This interaction (electromagnetic dressing) is shown to renormalize substantially electron velocities and the band gap in gapped graphene. Particularly, renormalized electronic parameters depend strongly on the field polarization: linearly polarized fields always reduce the gap, while circularly polarized fields break the equivalence of the valleys at various points of the Brillouin zone and can increase or decrease the corresponding band gaps. Moreover, a linearly polarized dressing field induces anisotropy of electron dispersion in the graphene plane. Consequently, dressing fields can be an effective tool to control electronic properties of graphene and be prospectively used in various optoelectronic devices. [ABSTRACT FROM AUTHOR]

It is demonstrated theoretically that the interaction of gapped 2D materials (gapped graphene and transition metal dichalchogenide monolayers) with a strong high-frequency electromagnetic field (dressing field) crucially changes the band structure of the materials. As a consequence, the renormalized band structure of the materials drastically depends on the field polarization. Particularly, a linearly polarized dressing field always decreases band gaps, whereas a circularly polarized field breaks the equivalence of band valleys in different points of the Brillouin zone and can both increase and decrease corresponding band gaps. It is shown also that a dressing field can turn both the band gaps and the spin splitting of the bands into zero. As a result, the dressing field can serve as an effective tool to control spin and valley properties of the materials in various optoelectronic applications. [ABSTRACT FROM AUTHOR]

We study dispersion properties of TM-polarized electromagnetic waves guided by a multilayer graphene metamaterial. We demonstrate that both dispersion and localization of the guided modes can be efficiently controlled by changing the number of layers in the structure. Remarkably, we find that in the long wavelength limit, the dispersion of the fundamental mode of the N-layer graphene structure coincides with the dispersion of a plasmon mode supported by a single graphene layer, but with N times larger conductivity. We also compare our exact dispersion relations with the results provided by the effective media model. [ABSTRACT FROM AUTHOR]

We study the propagation of electromagnetic waves through a slab of graphene metamaterial composed of the layers of graphene separated by dielectric slabs. Starting from the kinetic expression for two-dimensional electric current in graphene, we derive a novel equation describing the nonlinear propagation of terahertz electromagnetic pulses through the layered graphene-dielectric structure in the presence of losses and non-linearities. We demonstrate strong nonlinearity-induced reshaping of transmitted and reflected terahertz pulses through the interaction with the thin multilayer graphene metamaterial structure. [ABSTRACT FROM AUTHOR]

Two possible InGaAs/GaAs quantum-well structures ensuring the presence of radiative transitions between the polariton states in a microresonator with a quantum well, which are accompanied by generation of terahertz photons, are discussed in this work. For the first structure, symmetry breakdown that is required for the emission of a terahertz photon is conducted in a quantum well with refractive index gradient profile, which results in mixing of the states of a polariton and a dark exciton. Parameters of the quantum well, in which the energy of the second exciton level corresponds to the upper polariton energy, are determined. A double quantum well with exciton states split due to quantum-mechanical tunneling through a barrier is used in the second structure. Symmetry breakdown, which allows one to mix an exciton with a “dark” exciton, is ensured by adjusting the energy of electron levels in a double quantum well by applying an electric field to the structure. A hole remains localized in one of the wells. [ABSTRACT FROM AUTHOR]

Plasmon modes in a waveguide formed by two parallel graphene layers with an insulator spacer layer are considered. The existence of TM and TE guided modes is predicted and their properties are compared with those of plasmons in metal/insulator waveguides. [ABSTRACT FROM AUTHOR]

We study electromagnetic waves localized near the surface of a semi-infinite dielectric medium covered by a graphene layer in the presence of a strong external magnetic field. We demonstrate that a novel type of hybrid TE-TM polarized surface plasmons can propagate along the graphene layer. We analyze the effect of the Hall conductivity on the polarization properties of these hybrid surface waves and suggest a possibility to tune the graphene plasmons by the external magnetic field. [ABSTRACT FROM AUTHOR]

We analyze time evolution of spatial coherence of a polariton ensemble in a quantum wire (1D channel) under constant uniform resonant pumping. Using the theoretical approach based on the Lindblad equation for a one-particle density matrix, which takes into account the polariton-phonon and excitonexciton interactions, we study the behavior of the first-order coherence function g for various pump intensities and temperatures in the range of 1-20 K. Bistability and hysteresis in the dependence of the first-order coherence function on the pump intensity is demonstrated. [ABSTRACT FROM AUTHOR]

A new type of waveguide mode formed by two coupled Tamm plasmon polaritons localized at the boundaries of a Bragg reflector bounded by two metal surfaces has been studied. [ABSTRACT FROM AUTHOR]