Sign flips, crossovers, and spatial inversions in surface plasmon resonance across a chiral-metal interface.

We consider the surface plasmon resonance established along an interface between a metal and a chiral medium (chiral case). Resulting solutions are compared with those obtained for a metal-dielectric interface (achiral case). We found that the chiral case exhibits either larger or smaller phase speeds than the achiral case due to the energy redistribution between translation and rotation. For a loss-free system, we found crossovers among the dispersion curves and spatial inversions in field profiles. These features are associated with anti-symmetric spin flips with respect to medium chirality. The short-wavelength limit leads to an upper bound on the medium chirality.

Plasmonically induced magnetic field in graphene-coated nanowires.

In this Letter, we investigate a magnetic field induced by guiding plasmonic modes in graphene-coated nanowire via an inverse Faraday effect. Magnetic field distribution for different plasmonic modes has been calculated. It has been shown that a magnetic field has a vortex-like distribution for some plasmonic modes. The possibility of producing magnetic field distribution that rotates along the nanowire axis and periodically depends on azimuthal angle has been demonstrated.

Complex relaxation rates of the Drude metals and their effects on the lifetime and symmetry of plasmon resonances.

The Drude model for metal is extended to include complex relaxation rates. As a test for what happens to the surface plasmon resonances with such metals, the lifetime is examined for propagating waves across a single planar metal-dielectric interface. By analytically solving the dispersion relation being fourth-order in the complex frequency, group-velocity dispersion and quality factors are explicitly found. Due to the symmetry breaking between the forward and backward waves, standing waves are not allowed in general.

Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations.

This study is motivated in part to better understand multiplexing in wireless communications, which employs photons carrying varying angular momenta. In particular, we examine both transverse electric (TE) and transverse magnetic (TM) waves in either co-rotations or counter-rotations. To this goal, we analyze both Poynting-vector flows and orbital and spin parts of the energy flow density for the combined fields. Consequently, we find not only enhancements but also cancellations between the two modes. To our surprise, the photon spins in the azimuthal direction exhibit a complete annihilation for the counter-rotational case even if the intensities of the colliding waves are of different magnitudes. In contrast, the orbital flow density disappears only if the two intensities satisfy a certain ratio. In addition, the concepts of spin sifters and enantiomer sorting are illustrated.

Wave propagation and resonance in four-layer systems for organic light-emitting diodes.

Wave propagation and surface plasmon resonance are examined in four-layer optical systems in slab geometry for an OLED (organic light-emitting diode) with an embedded thin metal film. For this purpose, both leaky and bound modes are examined in all ranges of the propagation constant, which determines how surface and volume waves are allowed. Intensive parametric studies are performed on the thicknesses of the two embedded layers, along with the cathode condition and the metal's material dispersion. As a way of interpreting the results, the direction of the depthwise wave propagation is examined in connection with possible excitations arising from light sources within the organic electroluminescence layer. Consequently, several new features are observed on the multiple-wave branches, including exchange of the phase speeds and depthwise standing waves for dissipationless systems. By the insertion of a thin metal film, the light extraction is found to be enhanced through leaky waves from the source layer out toward the viewer's side.