Patent ID: 9297937
Filing Date: 2016-03-29
CPC Classification: A61K,A61P,G02B

Claim Text:
1. A diffraction grating comprising: a substrate comprising a first dielectric or semiconductor material substantially transparent over a range of operational wavelengths λ with a refractive index n a set of diffractive elements formed on the first surface of the substrate, wherein the diffractive elements comprise a set of protruding ridges separated by intervening trenches characterized by a ridge spacing Λ, a ridge width d, and a ridge height h; a metal layer on a top surface of each ridge characterized by a thickness t; and a lateral metal layer on at least one side surface of each ridge, wherein each lateral metal layer extends a distance a downward from the top surface of the corresponding ridge and is characterized by a lateral thickness b, wherein: at least a portion of a bottom surface of each trench is substantially free of metal; λ/2n n