Showing papers by "David Schurig published in 2002"
••
TL;DR: In this article, the sensitivity of the subwavelength focus to various slab parameters, pointing out the connection to slab plasmon modes, is discussed, and a paradox associated with the perfect imaging of a point source is resolved.
Abstract: Recently it has been proposed that a planar slab of material, for which both the permittivity and permeability have the values of -1, could bring not only the propagating fields associated with a source to a focus, but could also refocus the nonpropagating near-fields, thereby achieving a subdiffraction image. In this work we discuss the sensitivity of the subwavelength focus to various slab parameters, pointing out the connection to slab plasmon modes. We also note and resolve a paradox associated with the perfect imaging of a point source. We conclude that subwavelength resolution is achievable with available technology, but only by implementation of a critical set of design parameters.
361 citations
••
TL;DR: In this article, a slab of a medium with negative refractive index bounded by media of different positive refractive indices was shown to act as a near-perfect lens for evanescent waves.
Abstract: We extend the ideas of the perfect lens recently proposed [J.B. Pendry, Phys. Rev. Lett. 85, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different positive refractive index also amplifies evanescent waves and can act as a near-perfect lens. We examine the role of the surface states in the amplification of the evanescent waves. The image resolution obtained by this asymmetric lens is more robust against the effects of absorption in the lens. In particular, we study the case of a slab of silver, which has a negative dielectric constant, with air on one side and other media such as glass or GaAs on the other side as an ‘asymmetric’ lossy near-perfect lens for p-polarized waves. It is found that retardation has an adverse effect on the imaging due to the positive magnetic permeability of silver, but we conclude that subwavelength image resolution is possible in spite of it.
163 citations
••
TL;DR: In this article, it was shown that a modulated Gaussian beam undergoes negative refraction at the interface between a positive and negative refractive index material, and the interference fronts appear to bend in a manner suggesting positive refraction, such that the true direction of the energy flow associated with the refracted beam is not obvious.
Abstract: We show that a modulated Gaussian beam undergoes negative refraction at the interface between a positive and negative refractive index material. While the refraction of the beam is clearly negative, the modulation interference fronts are not normal to the group velocity, and thus exhibit a sideways motion relative to the beam—an effect due to the inherent frequency dispersion associated with the negative index medium. In particular, the interference fronts appear to bend in a manner suggesting positive refraction, such that for a plane wave, the true direction of the energy flow associated with the refracted beam is not obvious.
137 citations
•
26 Aug 2002
TL;DR: In this article, a self-adjusting assembly and method for support assembly for supporting a device is described. But the authors do not describe the assembly and the method of self adjustment.
Abstract: A self-adjusting assembly and method are disclosed. In the disclosed embodiments, a support assembly for supporting a device comprises a pair of support members (4) for supporting the device (11). One of the members (4) is adapted to help support the device (11) from a ground (5), and another of the members (8) is adapted to provide lateral support for the device (11) and to permit free longitudinal movement of the device as it expands or contracts due to temperature variations.
3 citations
••
TL;DR: In this paper, it was shown that a slab of a medium with negative refractive index bounded by media of different positive refractive indices also amplifies evanescent waves and can act as a near perfect lens.
Abstract: We extend the ideas of the recently proposed perfect lens [J.B. Pendry, Phys. Rev. Lett. {\bf 85}, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different positive refractive index also amplifies evanescent waves and can act as a near-perfect lens. We examine the role of the surface states in the amplification of the evanescent waves. The image resolution obtained by this asymmetric lens is more robust against the effects of absorption in the lens. In particular, we study the case of a slab of silver, which has negative dielectric constant, with air on one side and other media such as glass or GaAs on the other side as an `asymmetric' lossy near-perfect lens for P-polarized waves. It is found that retardation has an adverse effect on the imaging due to the positive magnetic permeability of silver, but we conclude that subwavelength image resolution is possible inspite of it.
2 citations
•
27 Aug 2002
TL;DR: In this paper, an ensemble de support composed of deux elements of support of a dispositif comprend de two elements de support of the maintien of the dispositifier.
Abstract: L'invention concerne un ensemble et un procede de reglage automatique. Dans les modes de realisation decrits, un ensemble de support destine a supporter un dispositif comprend deux elements de support de ce dispositif. L'un des elements est concu de facon a faciliter le maintien du dispositif a distance d'une surface d'appui, et l'autre etant concu de facon a fournir un support lateral audit dispositif et a autoriser le deplacement libre de ce dispositif dans le sens de la longueur au gre de dilatations et de contractions dues a des variations de temperature.