Patent ID: 9551648
Date: 2017-01-24
CPC Classifications: B82Y,G01N,G03F

Claim:
1. A substrate for generating surface plasmons (SPs) and surface plasmon polaritons (SPPs) by excitation radiation of a determined wavelength, comprising: a carrier layer transparent to the excitation radiation comprising a surface structure on a surface of the carrier layer, and a metal coating on the surface structure, the coating being suitable for propagating SPPs excited by the excitation radiation; and the surface structure comprising a plurality of spaced apart prolate recesses of an identical size, each recess having a length (L) in a longitudinal direction selected from a range between 100 nm and 2500 nm, a width (B) in a transverse direction orthogonal to the longitudinal direction, and a depth (T), wherein each recess is elongated in the length L with respect to the width B; the plurality of the recesses being arranged in rows and columns of a two dimensional array, wherein longitudinal directions of the prolate recesses are parallel to one another and wherein the columns form an angle α relative to the rows, the array having a first periodicity (P