Patent ID: 6922287
Filing Date: 2005-07-26
Classification: G02B

Abstract:
1. A light coupling element having a surface ( 3 ) of a material which is transparent to light of a selected wavelength λ, for producing an evanescent electromagnetic field at the surface ( 3 ), the element comprising: a first set of equidistantly parallel indentations ( 5 1 ) on at least one region of the surface ( 3 ); and a further set of equidistantly parallel indentations ( 5 2 ) on the surface ( 3 ) which intersect (φ) the first set of indentations ( 5 1 ), wherein all said indentations ( 5 1 , 5 2 ) are linear and wherein the distances (d 0 ) of successive equidistantly parallel indentations ( 5 1 , 5 2 ) are equal and relative to the selected wavelength λ in air are selected as follows: and wherein the surface ( 3 ) is the surface of a layer system ( 1 a ) with at least one layer which is applied onto a support ( 15 ), wherein the material of the support ( 15 ) has a refractive index for the light of the selected wavelength λ which is lower than the refractive index of a layer material of the layer system.