Abstract The reflector on an impulse radiating antennas (IRAs) is normally designed to be paraboloidal in shape, and are oriented so that the electrical feed point of the TEM feed line coincides with the focal point of the paraboloid. In many practical cases, the feed point and focal points are not exactly aligned, producing some defocus of the reflector. There are two types of defocus that can...

Abstract We report on a series of detailed Breit-Pauli and Dirac B-spline R-matrix (DBSR) differential cross section (DCS) calculations for excitation the $$5\,^2\textrm{S}_{1/2} \rightarrow 5\,^2\textrm{P}_{1/2}$$ 5 2 S <...

We report the experimental demonstration of a new design for external cavity hybrid lasers consisting of a III-V semiconductor optical amplifier (SOA) with fiber reflector and a photonic crystal (PhC)-based resonant reflector on SOI. The silicon reflector is composed of an SU8 polymer bus waveguide vertically coupled to a PhC cavity and provides a wavelength-selective optical feedback to the la...

A Polarization-Conversion Guided Mode (PCGM) technique has been developed to quantify optical anisotropy as low as 10-5 for a surface layer only 10 nm thick. The optical geometry consists of an index-fluid matched prism-coupler and an air-gap waveguide comprising the thin sample on a glass plate as the incident surface with a gold reflector forming the other surface of the guide. This allows no...

Light management using intermediate reflector layers (IRL) and advanced front transparent conductive oxide (TCO) morphologies is needed to rise the short-circuit current density (Jsc) of micromorph tandem solar cells above 14 mA/cm. For micromorph cells deposited on surface-textured ZnO layers grown by low-pressure chemical vapour deposition (LPCVD), we study the interplay between the front TCO...

The suitability of various radiating systems for generating a directive high power microwave (HPhl ) beam is investigated. It is concluded that offset reflector antenna systems are well suited for this purpose. An HPM reflector antenna may consist of one or two reflectors that are illuminated by single or array feeds. To accurately predict the performance of an HPM reflector antenna, a versatil...

Abstract. Reflector antennas are characterized by very high gains (30 dB and higher) and narrow main beams. They are widely used in satellite and line-of-sight microwave communications as well as in radar. Reflector antennas operate on principles known long ago from the theory of geometrical optics. The first reflector system was made by Hertz back in 1888 (a cylindrical reflector fed by a dipo...

─ This paper presents and evaluates a parallel time domain analysis of a rectangular reflector on multicores machine. Rectangular reflector antennas have motivated the time-domain analysis of electromagnetic scattering problems. The asymptotic time domain physical-optics (TDPO) is applied to the analysis of a rectangular reflector illuminated by a Gaussian-impulse. It is a numerical technique u...

A high efficiency dye-doped cholesteric liquid crystal (CLC) is demonstrated by optimizing the dye concentration and using an electrically tunable nematic liquid crystal (NLC) phase retarder. The state of polarization of laser emission in CLC lasers, contrary to our expectations, due to the refractive index mismatch at the boundaries is not exactly circular. A double-cell structure including a ...

We present a resonant-cavity-enhanced Single Photon Avalanche Diode (SPAD) fabricated on a reflecting siliconon-insulator (SOI) substrate. The substrate incorporates a two period distributed Bragg reflector fabricated using a commercially available double-SOI process. The resonant-cavity-enhanced (RCE) SPAD detectors have peak photon detection efficiencies ranging from 41% at 780nm to 32% at 85...