Spontaneous reorientations of meta-atoms and electromagnetic spatial solitons in a liquid metacrystal.

We show that transverse electromagnetic waves propagating along an external static electric field in liquid metacrystal (LMC) can provoke spontaneous rearrangement of elongated meta-atoms that changes the direction of the anisotropy axis of the LMC. This kind of instability may reorient the meta-atoms from the equilibrium state parallel to a static field to the state along a high-frequency field and back at the different threshold intensities of electromagnetic waves in such a way that bistability in the system takes place. Reorientation of meta-atoms causes a change in the effective refraction index of LMC that creates, in turn, the conditions for the formation of bright spatial solitons.

Nonlinear control of invisibility cloaking.

We introduce a new concept of the nonlinear control of invisibility cloaking. We study the scattering properties of multi-shell plasmonic nanoparticles with a nonlinear response of one of the shells, and demonstrate that the scattering cross-section of such particles can be controlled by a power of the incident electromagnetic radiation. More specifically, we can either increase or decrease the scattering cross-section by changing the intensity of the external field, as well as control the scattering efficiently and even reverse the radiation direction.

Ideal and nonideal invisibility cloaks.

We employ the analytical solutions for the spatial transformation of the electromagnetic fields to obtain and analyze explicit expressions for the structure of the electromagnetic fields in invisibility cloaks. Similar approach can be also used for analyzing beam splitters and field concentrators. We study the efficiency of nonideal electromagnetic cloaks and discuss the effect of scattering losses on the cloak invisibility.

Inside-out electromagnetic cloaking.

We introduce a novel concept of an inside-out (or inverse) cloak for electromagnetic waves based on the coordinate transformation of Maxwell's equations. This concept can be employed for creating absorbing non-reflecting media as matching layers in numerical simulations. In contrast to the commonly used perfectly matched layers, such absorbing boundaries are characterized by physically meaningful parameters, and the concept can be used in various numerical simulation schemes.

Nonlinear transmission and spatiotemporal solitons in metamaterials with negative refraction.

We study one- and two-dimensional transmission of electromagnetic waves through a finite slab of a dielectric material with negative refraction. In the case when the dielectric slab possesses an intensitydependent nonlinear response, we observe the nonlinearity-induced wave transmission through an opaque slab accompanied by the generation of spatiotemporal solitons. We solve this problem numerically, by employing the finite-difference time-domain simulations, for the parameters of microstructured materials with the negative refractive index in the microwave region, but our results can be useful for a design of nonlinear metamaterials with the left-handed properties in other frequency range.

Defect modes and transmission properties of left-handed bandgap structures.

We analyze transmission of electromagnetic waves through a one-dimensional periodic layered structure consisting of slabs of a left-handed metamaterial and air. We derive the effective parameters of the metamaterial from a microscopic structure of wires and split-ring resonators possessing the left-handed characteristics in the microwave frequency range, and then study, by means of the transfer-matrix approach and the finite-difference time-domain numerical simulations, the transmission properties of this layered structure in a band gap associated with the zero averaged refractive index. By introducing defects, the transmission of such a structure can be made tunable, and we study the similarities and differences of the defects modes excited in two types of the band gaps.