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Showing papers by "David Schurig published in 2004"


Journal ArticleDOI
TL;DR: In this article, a detailed analysis of the refraction and reflection behavior of electromagnetic waves at an interface between an indefinite medium and vacuum is presented, and it is shown that certain classes of indefinite media have identical refractive properties as isotropic negative index materials.
Abstract: Initial experiments on wedge samples composed of isotropic metamaterials with simultaneously negative permittivity and permeability have indicated that electromagnetic radiation can be negatively refracted. In more recently reported experiments [Phys. Rev. Lett. 90, 1074011 (2003)], indefinite metamaterial samples, for which the permittivity and permeability tensors are negative along only certain of the principal axes of the metamaterial, have also been used to demonstrate negative refraction. We present here a detailed analysis of the refraction and reflection behavior of electromagnetic waves at an interface between an indefinite medium and vacuum. We conclude that certain classes of indefinite media have identical refractive properties as isotropic negative index materials. However, there are limits to this correspondence, and other complicating phenomena may occur when indefinite media are substituted for isotropic negative index materials. We illustrate the results of our analysis with finite-element-based numerical simulations on planar slabs and wedges of negative index and indefinite media.

238 citations


Journal ArticleDOI
TL;DR: In this article, a metamaterial composed of split ring resonators, designed to provide a permeability equal to −1 along the longitudinal axis, was shown to redirect s-polarized electromagnetic waves from a nearby source to a partial focus.
Abstract: Negative refraction can occur at the interface between vacuum and an indefinite medium—an anisotropic medium for which not all elements of the permittivity and permeability tensors have the same sign. We show experimentally and via simulations that a metamaterial composed of split ring resonators, designed to provide a permeability equal to −1 along the longitudinal axis, will redirect s-polarized electromagnetic waves from a nearby source to a partial focus. The dispersion characteristics of indefinite media prohibit the possibility of true aplanatic points for a planar slab; however, by contouring the surfaces aplanatic points may be realized, as well as other geometrical optical behavior.

199 citations


Journal ArticleDOI
TL;DR: This work examines the Seidel aberrations of thin spherical lenses composed of media with refractive index not restricted to be positive and finds that spherical lenses possessing real aplanatic focal points are possible only with a negative index.
Abstract: We examine the Seidel aberrations of thin spherical lenses composed of media with refractive index not restricted to be positive. We find that consideration of this expanded parameter space allows for the reduction or elimination of more aberrations than is possible with only positive index media. In particular, we find that spherical lenses possessing real aplanatic focal points are possible only with a negative index. We perform ray tracing, using a custom code that relies only on Maxwell's equations and conservation of energy, that confirms the results of the aberration calculations.

78 citations


Journal ArticleDOI
TL;DR: In this paper, a scanning magnetic microscope (SMM) with 25 µm resolution in spatial position for the magnetic features of room temperature objects was developed. But, it is not suitable for the use of high-temperature superconductor (HTS) dc SQUID sensor.
Abstract: We have developed a scanning magnetic microscope (SMM) with 25 µm resolution in spatial position for the magnetic features of room temperature objects. The microscope consists of a high-temperature superconductor (HTS) dc SQUID sensor, suspended in vacuum with a self-adjusting standoff, close spaced liquid nitrogen Dewar, X–Y scanning stage and a computer control system. The HTS SQUIDs were optimized for better spatial and field resolutions for operation at liquid nitrogen temperature. Measured inside a magnetic shield, the 10 pT Hz−1/2 typical noise of the SQUIDs is white down to frequencies of about 10 Hz, increasing up to about 20 pT Hz−1/2 at 1 Hz. The microscope is mounted on actively damped platforms, which negate vibrations from the environment as well as damping internal stepper motor noises. A high-resolution video telescope and a 1 µm precision z-axis positioning system allow a close positioning of the sample under the sensor. The ability of the sensors to operate in unshielded environmental conditions with magnetic fields up to about 15 G allowed us to perform 2D mapping of the local ac and dc susceptibility of the objects.

17 citations