Light Scattering on Nanowire Antennas: A Semi-Analytical Approach

Two semi-analytical approaches to solve the problem of light scattering on nanowire antennas are developed and compared. The derivation is based on the exact solution of the plane wave scattering problem in case of an infinite cylinder. The original three-dimensional problem is reduced in two alternative ways to a simple one-dimensional integral equation, which can be solved numerically by a method of moments approach. Scattering cross sections of gold nanowire antennas with different lengths and aspect ratios are analysed for the optical and near-infrared spectral range. Comparison of the proposed semi-analytical methods with the numerically rigorous discrete dipole approximation method demonstrates good agreement as well as superior numerical performance.Comment: 9 pages, 5 figure

Oblique frozen modes in periodic layered media

We study the classical scattering problem of a plane electromagnetic wave incident on the surface of semi-infinite periodic stratified media incorporating anisotropic dielectric layers with special oblique orientation of the anisotropy axes. We demonstrate that an obliquely incident light, upon entering the periodic slab, gets converted into an abnormal grazing mode with huge amplitude and zero normal component of the group velocity. This mode cannot be represented as a superposition of extended and evanescent contributions. Instead, it is related to a general (non-Bloch) Floquet eigenmode with the amplitude diverging linearly with the distance from the slab boundary. Remarkably, the slab reflectivity in such a situation can be very low, which means an almost 100% conversion of the incident light into the axially frozen mode with the electromagnetic energy density exceeding that of the incident wave by several orders of magnitude. The effect can be realized at any desirable frequency, including optical and UV frequency range. The only essential physical requirement is the presence of dielectric layers with proper oblique orientation of the anisotropy axes. Some practical aspects of this phenomenon are considered.Comment: text and 9 figure

Photonic crystal couplers for slow light

We propose a general approach to the design of directional couplers in photonic-crystals operating in the slowlight regime. We predict, based on a general symmetry analysis, that robust switching of slow-light pulses is possible between antisymmetricall

Multiple lesions on CT brain scan: tuberculosis or neurocysticercosis?

An 8-year-old girl with miliary tuberculosis, receiving appropriate treatment, presented with clinical features suggestive of increased intracranial pressure. She tested positive with the highly sensitive and specific1 enzyme-linked immunoelectrotransfer blot assay for cysticercosis