Vyacheslav V. Khardikov

Nanostructured Metal Film with Asymmetric Optical Transmission

We demonstrate for the first time a nanostructured planar photonic metamaterial transmitting light differently in forward and backward directions.

A giant red shift and enhancement of the light confinement in a planar array of dielectric bars

The results of research into resonant phenomena in double-periodic subwavelength planar structures made up of paired dielectric bars are presented. For the first time the existence of high Q-factor trapped mode resonances is revealed in these low-loss entirely dielectric structures. A large red shift of the trapped mode resonance of the structure is observed as compared with the resonant wavelength of the periodic structure with only one dielectric bar per unit cell. This shift of the resonant wavelength is caused by a strong coupling of the electromagnetic fields in the adjacent dielectric bar resonators.

Planar all-silicon metamaterial for terahertz applications

We propose and investigate a novel planar resonant all-silicon metamaterial. The metamaterial has a simple design. Unit cell of the periodic structure consists of silicon resonator in the form of right square prism. The prisms are connected between them by silicon bridges. The metamaterial exhibits sharp resonant reflection and transmission responses corresponding to excitation of two kinds of trapped mode regimes. These regimes are based on the first and the second magnetic dipole resonances of the unit cell.

Optical magnetic mirror

We report demonstration of an optical magnetic mirror achieved by nanostructuring a metal surface. In contrast to normal mirrors, it inflicts only small change to the phase of a reflected wave, offering intriguing applications.

All-Dielectric Resonant Metasurfaces with a Strong Toroidal Response

We demonstrate how to create all-dielectric metasurfaces with a strong toroidal response by arranging two types of nanodisks into asymmetric quadrumer clusters. We demonstrate that a strong axial toroidal response of the metasurface is related to conditions of the trapped (dark) mode that is excited due the symmetry breaking in the cluster. We study the correlation between the toroidal response and asymmetry in the metasurface and nanocluster geometries, which appears from the different diameters of nanodisks or notches introduced into the nanodisks.

Electromagnetic Wave Diffraction by Periodic Planar Metamaterials with Nonlinear Constituents

We present a theory which explains how to achieve an enhancement of nonlinear effects in a thin layer of nonlinear medium by involving a planar periodic structure specially designed to bear a trapped-mode resonant regime. In particular, the possibility of a nonlinear thin metamaterial to produce the bistable response at a relatively low input intensity due to a large quality factor of the trapped-mode resonance is shown. Also a simple design of an all-dielectric low-loss silicon-based planar metamaterial which can provide an extremely sharp resonant reflection and transmission is proposed. The designed metamaterial is envisioned for aggregating with a pumped active medium to achieve an enhancement of quantum dots luminescence and to produce an all-dielectric analog of a ‘lasing spacer’.

Fast Algorithm for Solving of the Light Diffraction Problem on Planar Periodic Structures

Fast algorithm for solving problems of light diffraction by real planar periodic metal-dielectric optical structures is proposed. This algorithm combines the numerical time domain simulation of the non-uniform region in periodic arrays of metal strips vicinity with analytical frequency domain transmission matrix method for the thick uniform substrate. To illustrate effectiveness of proposed method the reflectivity of a planar optical periodic structure with two arrays of C-shaped metal elements was calculated. The method can be used for optimization of properties of optical planar metamaterials.

Combining PSTD-Method and Transmission Matrices for Research of Planar Optical Metamaterials

Fast algorithm for solving problems of light diffraction by planar periodic metal-dielectric optical structures is proposed. This algorithm combines the numerical time domain simulation of the non-uniform region in periodic array of metal strips vicinity with analytical frequency domain transmission matrix method for the thick uniform substrate. To illustrate effectiveness of proposed method the reflectivity of a planar optical periodic structure of C-shaped metal elements was calculated. The method can be used for optimization of properties of optical planar metamaterials.

Influence of defects on electrodynamic properties of a semi-infinite periodic sequence of the metal-dielectric scatterers

A semi-infinite periodic sequence of metal-dielectric scatterers with defects in N basic elements is investigated. An analysis of the dynamical electromagnetic properties of the investigated structure was carried out for different polarization of the exciting field and degree of electrodynamic connection between resonance volumes.

High-quality trapped modes in all-dielectric metamaterials

A planar all-dielectric metamaterial made of a double-periodic lattice whose unit cell consists of a single subwavelength dielectric particle having the form of a disk possessing a penetrating hole is considered. The resonant states in the transmitted spectra of the metamaterial are identified considering modes inherent to the individual cylindrical dielectric resonator. A correlation between the asymmetry in the particles geometry, which arises from the off-centered displacement of the hole and the formation of the Mie-type and trapped modes, is established. The advantages of using a coaxial-sector notch instead of a round hole for the trapped mode excitation are explained.