Radiation from an axial electric dipole with prolate spheroidal metamaterial cloak cover
Exact analytical expressions for the electromagnetic field due to a dipole source located inside and along the axis of symmetry of a prolate spheroid are provided.
Exact Imaging by an Elliptic Lens
The radiation from an isotropic line source located at one of the focal lines of an elliptic cylindrical lens filled with a homogeneous and lossless DNG metamaterial is determined exactly in the frequency domain. This exact solution is compared to a previously derived optical solution.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.