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M Nietovesperinas - One of the best experts on this subject based on the ideXlab platform.

  • transmission study of prisms and slabs of lossy negative index media
    Optics Express, 2004
    Co-Authors: Juan Luis Garciapomar, M Nietovesperinas
    Abstract:

    Within an effective medium theory, we numerically study by means of a finite element method the transmission properties of prisms and slabs of media with negative refractive index. The constitutive parameters employed are similar to those of recent experiments that confirmed the existence of negative Refraction as well as the focusing property of flat slabs. In this way, we further analyze in detail the influence of diffraction and scattering due to the large wavelength of the radiation in use, and its suppression by employing waveguide configurations with absorbing walls. Also, we address the effects of different amounts of absorption on both the Angle of Refraction, (for which we derive a new Refraction law in prisms), and on the position, resolution and isoplantism of the focus produced by flat slabs.

T Dumelow - One of the best experts on this subject based on the ideXlab platform.

Jin Au Kong - One of the best experts on this subject based on the ideXlab platform.

  • Refraction laws for anisotropic media and their application to left handed metamaterials
    IEEE Transactions on Microwave Theory and Techniques, 2005
    Co-Authors: Tomasz M Grzegorczyk, M Nikku, Xudong Chen, Jin Au Kong
    Abstract:

    The Refraction of phase and power at the interface between free space and anisotropic media is studied. Under a TE incidence (electric field along y/spl circ/) and k/sub y/=0 incidence (where k/sub y/ is the y/spl circ/ component of the wave vector), a closed-form generalization of Snell's laws is proposed. The two relations (one for the phase and one for the power) are expressed in terms of the incident Angle, the constitutive parameters of the anisotropic medium (which can take negative values), and the tilting Angle of the dispersion relation. In addition, both positive and negative dispersions are discussed, making the formulas directly usable for the design of left-handed metamaterials. The validation is done by two methods. First, the electromagnetic fields in layered anisotropic media are computed analytically. The Angle of Refraction of the wave vector is thus directly obtained, while that of the power is obtained by computing the time-average Poynting power. Second, numerical simulations are performed using HFSS to record the deflection of the power by a prism characterized by positive or negative constitutive parameters. For the specific prism experiment, in which the incident Angle is equal to the tilting Angle of the dispersion relation, we show that the Refraction laws reduce to a simple Snell's law form.

T Itoh - One of the best experts on this subject based on the ideXlab platform.

  • full wave verification of the fundamental properties of left handed materials in waveguide configurations
    Journal of Applied Physics, 2001
    Co-Authors: Christophe Caloz, Chinchang Chang, T Itoh
    Abstract:

    The fundamental electromagnetic properties of left-handed materials (LHMs) are reviewed and verified by finite-element method full-wave analysis using rectangular waveguide structures loaded by a LHM and adopting an effective medium approach. The negative phase velocity, positive intrinsic impedance, and modified boundary conditions at an interface with a right-handed medium are verified by loading a waveguide section with a LHM that has edges perpendicular to the waveguide axis. In addition, the negative Angle of Refraction is demonstrated by loading the junction of a T-junction waveguide with a LHM having one edge 45° with respect to the waveguide axis. These properties are shown by the evolution of wave fronts in the LHM and by analysis of the S-parameters of the waveguide structures.

Juan Luis Garciapomar - One of the best experts on this subject based on the ideXlab platform.

  • transmission study of prisms and slabs of lossy negative index media
    Optics Express, 2004
    Co-Authors: Juan Luis Garciapomar, M Nietovesperinas
    Abstract:

    Within an effective medium theory, we numerically study by means of a finite element method the transmission properties of prisms and slabs of media with negative refractive index. The constitutive parameters employed are similar to those of recent experiments that confirmed the existence of negative Refraction as well as the focusing property of flat slabs. In this way, we further analyze in detail the influence of diffraction and scattering due to the large wavelength of the radiation in use, and its suppression by employing waveguide configurations with absorbing walls. Also, we address the effects of different amounts of absorption on both the Angle of Refraction, (for which we derive a new Refraction law in prisms), and on the position, resolution and isoplantism of the focus produced by flat slabs.