13 research outputs found
A new mechanism for negative refraction and focusing using selective diffraction from surface corrugation
Refraction at a smooth interface is accompanied by momentum transfer normal
to the interface. We show that corrugating an initially smooth, totally
reflecting, non-metallic interface provides a momentum kick parallel to the
surface, which can be used to refract light negatively or positively. This new
mechanism of negative refraction is demonstrated by visible light and microwave
experiments on grisms (grating-prisms). Single-beam
all-angle-negative-refraction is achieved by incorporating a surface grating on
a flat multilayered material. This negative refraction mechanism is used to
create a new optical device, a grating lens. A plano-concave grating lens is
demonstrated to focus plane microwaves to a point image. These results show
that customized surface engineering can be used to achieve negative refraction
even though the bulk material has positive refractive index. The surface
periodicity provides a tunable parameter to control beam propagation leading to
novel optical and microwave devices.Comment: 6 pages, 7 figures in RevTex forma
Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals
We demonstrate negative refraction of microwaves in metallic photonic
crystals. The spectral response of the photonic crystal, which manifests both
positive and negative refraction, is in complete agreement with band-structure
calculations and numerical simulations. The negative refraction observed
corresponds to left-handed electromagnetism and arises due to the dispersion
characteristics of waves in a periodic medium. This mechanism for negative
refraction is different from that in metamaterials.Comment: 13 pages, 4 figure
Loss-of-function variants in C3ORF52 result in localized autosomal recessive hypotrichosis
Novel nonsense variants in SLURP1 and DSG1 cause palmoplantar keratoderma in Pakistani families
Inherited palmoplantar keratodermas (PPKs) are clinically and genetically heterogeneous and phenotypically diverse group of genodermatoses characterized by hyperkeratosis of the palms and soles. More than 20 genes have been reported to be associated with PPKs including desmoglein 1 (DSG1) a key molecular component for epidermal adhesion and differentiation. Mal de Meleda (MDM) is a rare inherited autosomal recessive genodermatosis characterized by transgrediens PPK, associated with mutations in the secreted LY6/PLAUR domain containing 1 (SLURP1) gene.This article is freely available online via Open Access. Click on the Publisher URL to access the full-text via the publisher's site