Richard W. Ziolkowski

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—A metamaterial paradigm for achieving an efficient, electrically small antenna is introduced. Spherical shells of homogenous , isotropic negative permittivity (ENG) material are designed to create electrically small resonant systems for several antennas: an infinitesimal electric dipole, a very short center-fed cylindrical electric dipole, and a very short(More)
—The effect of surrounding an electrically small dipole antenna with a shell of double negative (DNG) material (0 and 0) has been investigated both analytically and numerically. The problem of an infinitesimal electric dipole embedded in a homogeneous DNG medium is treated; its analytical solution shows that this electrically small antenna acts inductively(More)
—The design, fabrication and measurement of a volu-metric metamaterial realization of an artificial magnetic conductor (AMC) is presented. In contrast to most current realizations of AMCs, such as the mushroom and the uniplanar compact photonic bandgap surfaces, the present design has no perfect electric conductor ground plane. The perfect magnetic(More)
The extension of the conventional finite-difference time-domain solution of the full vector Maxwell equations to modeling femtosecond optical-pulse propagation in a nonlinear Kerr medium that exhibits a finite response time is presented. Numerical results are given for nonlinear self-focusing in two space dimensions and time; the technique can be(More)
We extend to more than one spatial dimension the semiclassical full-wave vector Maxwell-Bloch equations for the purpose of achieving an adequate and rigorous description of ultrashort pulse propagation in optical waveguides containing resonant nonlinearities. Our considerations are based on the generalized pseudospin formalism introduced by Hioe and Eberly(More)
—Planar two-dimensional (2D) and volumetric three-dimensional (3D) metamaterial-inspired efficient electrically-small antennas that are easy to design; are easy and inexpensive to build; and are easy to test; are reported, i.e., the EZ antenna systems. The proposed 2D and 3D electrical-and magnetic-based EZ antennas are shown to be naturally matched to a 50(More)
—A model of an idealized radiating system composed of an electrically small electric dipole antenna enclosed in an electrically small multilayered metamaterial shell system is developed analytically. The far-field radiation characteristics of this system are optimized using a GA-MATLAB based hybrid optimization model. The optimized-analytical model is(More)
The optical properties of a concentric nanometer-sized spherical shell comprised of an (active) 3-level gain medium core and a surrounding plasmonic metal shell are investigated. Current research in optical metamaterials has demonstrated that including lossless plasmonic materials to achieve a negative permittivity in a nano-sized coated spherical particle(More)