Ivan Iorsh

Hyperbolic metamaterials based on multilayer graphene structures

We suggest a new class of hyperbolic metamaterials for THz frequencies based on multilayer graphene structures. We calculate the dielectric permittivity tensor of the effective nonlocal medium with a periodic stack of graphene layers and demonstrate that tuning from elliptic to hyperbolic dispersion can be achieved with an external gate voltage. We reveal that such graphene structures can demonstrate a giant Purcell effect that can be used for boosting the THz emission in semiconductor devices. Tunability of these structures can be enhanced further with an external magnetic field which leads to the unconventional hybridization of the TE and TM polarized waves.

Manipulating polarization of light with ultrathin epsilon-near-zero metamaterials

One of the basic functionalities of photonic devices is the ability to manipulate the polarization state of light. Polarization components are usually implemented using the retardation effect in natural birefringent crystals and, thus, have a bulky design. Here, we have demonstrated the polarization manipulation of light by employing a thin subwavelength slab of metamaterial with an extremely anisotropic effective permittivity tensor. Polarization properties of light incident on the metamaterial in the regime of hyperbolic, epsilon-near-zero, and conventional elliptic dispersions were compared. We have shown that both reflection from and transmission through λ/20 thick slab of the metamaterial may provide nearly complete linear-to-circular polarization conversion or 90° linear polarization rotation, not achievable with natural materials. Using ellipsometric measurements, we experimentally studied the polarization conversion properties of the metamaterial slab made of the plasmonic nanorod arrays in different dispersion regimes. We have also suggested all-optical ultrafast control of reflected or transmitted light polarization by employing metal nonlinearities.

Hybrid waves localized at hyperbolic metasurfaces

ITMO University, St. Petersburg 197101, Russia(Dated: March 2, 2015)We reveal the existence of a new type of surface electromagnetic waves supported by hyperbolicmetasurfaces, described by a conductivity tensor with an inde nite signature. We demonstrate thatthe spectrum of the hyperbolic metasurface waves consists of two branches corresponding to hybridTE-TM waves with the polarization that varies from linear to elliptic or circular depending on thewave frequency and propagation direction. We analyze the e ect of losses of the surface waves andderive the corresponding analytical asymptotic expressions.I. INTRODUCTION

Parabolic polarization splitting of Tamm states in a metal-organic microcavity

We observe hybrid states of cavity photons and Tamm plasmons in an organic microcavity with an incorporated thin silver layer of increasing thickness up to 40 nm. Via μ-photoluminescence spectroscopy, we investigate their angular dependence. At oblique angles, we observe a TE-TM polarization splitting of more than 40 meV for each mode. An analytical model is developed to describe the coupling of Tamm plasmons and cavity photons and to account for the splitting of the orthogonally polarized resonances.

Plasmons in waveguide structures formed by two graphene layers

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.

Purcell effect in hyperbolic metamaterial resonators

The radiation dynamics of optical emitters can be manipulated by properly designed material structures modifyinglocaldensityofphotonicstates,aphenomenonoftenreferredtoasthePurcelleffect.Plasmonicnanorod metamaterials with hyperbolic dispersion of electromagnetic modes are believed to deliver a significant Purcell enhancement with both broadband and nonresonant nature. Here, we have investigated finite-size resonators formed by nanorod metamaterials and shown that the main mechanism of the Purcell effect in such resonators originates from the supported hyperbolic modes, which stem from the interacting cylindrical surface plasmon modes of the finite number of nanorods forming the resonator. The Purcell factors delivered by these resonator modes reach several hundreds, which is up to 5 times larger than those in the e-near-zero regime. It is shown �

Complex band structure of nanostructured metal-dielectric metamaterials

We study complex eigenmodes of layered metal-dielectric metamaterials. Varying losses from weak to realistic, we analyze band structure of the metamaterial and clarify effect of losses on its intrinsic electromagnetic properties. The structure operates in a regime with infinite numbers of eigenmodes, whereas we analyze dominant ones.

Interface modes in nanostructured metal-dielectric metamaterials

We study surface modes at an interface separating two different layered metal-dielectric metamaterials. We demonstrate that, in a sharp contrast to the effective-medium approach predicting a single interface mode with the surface-plasmon dispersion, the transfer-matrix method reveals the existence of three types of localized interface modes, including a backward interface mode. These results confirm that metal-dielectric nanostructured metamaterials can demonstrate strong optical nonlocality due to the excitation of surface plasmon polaritons.

Wireless power transfer based on magnetic quadrupole coupling in dielectric resonators

We numerically investigate a magnetic resonant wireless power transfer system based on high refractive index dielectric resonators. We propose to operate at magnetic quadrupole mode of the resonators to enlarge the efficiency due to minimization of ohmic and radiation losses. Numerical estimation predicts the 80% efficiency of the wireless power transfer (WPT) system operating at quadrupole mode at 300 MHz. Moreover, the system operating at magnetic quadrupole mode is capable of transferring power with 70% efficiency when the receiver rotates 90°. We verify the simulated results by experimental investigation of the WPT system based on microwave  ceramic  resonators (e = 80 and tanδ = 10−4).

Tunable hybrid surface waves supported by a graphene layer

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.