Photonic engineering of volume plasmon polaritons in multilayer hyperbolic metamaterials

Dr. Sergei Zhukovsky

Technical University of Denmark

Abstract:

Subwavelength metal-dielectric multilayers can be approximately regarded as anisotopic media having an effective permittivity tensor with components of different signs. Such multilayers, called hyperbolic metamaterials (HMMs), behave like metals or dielectrics depending on light polarization and feature exotic physical effects such as broadband singularity in the photonic density of states. It was shown that these photonic states are mainly populated by propagating high-k bulk plasmons, stemming from hybridization of short-range surface plasmon polaritons supported by the individual metallic layers. These high-k waves can have anomalously short wavelengths, which underlies the concept of far-field subwavelength imaging (hyperlensing) in HMMs.

In this talk, we show how propagation of high-k bulk plasmons can be tailored by modulating, or superstructuring, the filling fraction of metal in a subwavelength metal-dielectric stack on a longer scale, comparable to the wavelength of light. The basic superstructure geometry is a two-scale HMM where the modulation itself is periodic, forming a photonic band gap (PBG) for the high-k waves by the same principles as in conventional photonic crystals. Changing the geometry of the superstructure from a periodic to more complicated can then be used to purposely affect the properties of high-k wave propagation using known PBG-based approaches. It is thus possible to engineer a metamaterial where high-k bulk plasmons with desired properties are selectively reflected, transmitted, localized, suppressed or enhanced. As an example, we propose several designs of proof-of-principle multiscale devices such as Bragg reflectors, Fabry-Pérot resonators, and band pass filters for high-k waves. The proposed concept of multiscale HMMs can be used to tune the operation of HMM-based hyperlenses and subwavelength imaging devices.

Biography:

Sergei Zhukovsky acquired his Ph.D. degree in 2004 at the National Academy of Sciences in Minsk, Belarus, and did postdoctoral research at University of Bonn and University of Wuppertal (Germany). From 2009 to 2011 he was a postdoctoral fellow at U of T with Prof. John Sipe and Prof. Amr Helmy. He is presently a senior researcher and Marie Curie Fellow at Technical University of Denmark. His research interests are: photonic and plasmonic multilayers; photonic crystals; microlasers; chiral and hyperbolic metamaterials.