A simple method for achieving high-contrast vertical alignment of high birefringence (Dn 0.28) negative dielectric anisotropic liquid crystal mixture using buffed polyimide substrates is demonstrated. By doping a positive, or non-polar dielectric anisotropic compound or mixture to the laterally difluorinated tolane liquid crystal host, an excellent vertical alignment was obtained. This alignmen...

We study localized modes at a surface of a multilayer structure made of graphene layers separated by dielectric layers. We demonstrate the existence of deeply subwavelength surface modes that can be associated with the electromagnetic Tamm states, with the frequencies in the THz frequency range the negative group velocities. We suggest that the dispersion properties of these Tamm surface modes ...

In this paper, the properties of photonic band gaps (PBGs) for three-dimensional (3D) photonic crystals (PCs) composed of isotropic positive-index materials and epsilon-negative materials with pyrochlore lattices are theoretically investigated by a modified plane wave expansion method. The eigenvalue equations of calculating the band structures for such 3D PCs in the first irreducible Brillouin...

We introduce an effect of metallization of dielectric nanofilms by strong, adiabatically varying electric fields. The metallization causes optical properties of a dielectric film to become similar to those of a plasmonic metal (strong absorption and negative permittivity at low optical frequencies). This is a quantum effect, which is exponentially size-dependent, occurring at fields on the orde...

We perform extensive finite difference time domain simulations of ferrite based negative index of refraction composites. A wire grid is employed to provide negative permittivity. The ferrite and wire grid interact to provide both negative and positive index of refraction transmission peaks in the vicinity of the ferrite resonance. Notwithstanding the extreme anisotropy in the index of refractio...

We review recent progress in the development of high birefringence (Δn ≥ 0.12) negative dielectric anisotropy (Δε < 0) liquid crystals (LCs) for direct-view and projection displays. For mobile displays, our UCF-N2 (low viscosity, negative Δε, high Δn) based homogeneous alignment fringe-field switching (called n-FFS) mode exhibits superior performance to p-FFS in transmittance, single gamma curv...

We analyze the two-dimensional potential around a coated cylinder placed in a nonuniform field. In two special cases the system behaves as if the core of the cylinder were enlarged and the shell absent. These are when the shell dielectric constant is the negative of either the core dielectric constant or the matrix dielectric constant. When the shell dielectric constant has a small imaginary pa...

In natural ionic solids, cationic and anionic species are alternately arranged to minimize electrostatic energy. Aggregation of identical ionic species is commonly prohibited due to the repulsive, long-range nature of Coulombic interactions. Recently, we synthesized unique ionic solids, [AuI4CoIII2(dppe)2(D-pen)4]X2·nH2O (dppe = 1,2-bis(diphenylphosphino)ethane, D-pen = D-penicillaminate), in w...

Specially designed metal-dielectric composites can have a negative refractive index in the optical range. Specifically, it is shown that arrays of single and paired nanorods can provide such negative refraction. For pairs of metal rods, a negative refractive index has been observed at 1.5 μm. The inverted structure of paired voids in metal films may also exhibit a negative refractive index. A s...

We analyse the reflection of a TM electromagnetic field first on a flat dielectric film and second on a Veselago film with negative refractive index, both films being deposited on a metallic substrat acting as a mirror. An incident harmonic plane wave generates inside a conventional dielectric film a refracted propagating wave and an evanescent wave that does not contribute to reflection on the...