Patent ID: 6818907
Filing Date: 2004-11-16
Classification: A61K,B82Y,G01N,G01Q,G02B,G03F,G21K,H01J,H05H,Y10T

Abstract:
Apparatus for directing electromagnetic energy onto a target in a small area of illumination, said apparatus comprising, in combination,a source of electromagnetic radiation, a substantially planar light barrier interposed between side source and said target, said light barrier defining a first electrically conductive surface on the side of said barrier exposed to incident radiation from said source and further defining a second surface on the opposite side of said barrier, said second surface being positioned adjacent to said target, said first electrically conductive surface of said light barrier being formed by a layer of conductive metal having a thickness greater than the skin depth of said metal at the frequency of said electromagnetic radiation, and said light barrier further comprising a barrier material that is opaque to the transmission of said electromagnetic radiation, said barrier material being positioned between said layer of conductive metal and said second surface, said conductive metal and said barrier material having significantly different dielectric properties, one or more apertures through said light barrier, each of said apertures passing from said first surface to said second surface through said layer of conductive metal and through said barrier material, each of said apertures having a width in at least one dimension that is smaller than one wavelength of said electromagnetic radiation, wherein said barrier material confines the extent of the electronic excitation induced in said second surface to the portion of said second surface that is near each of said apertures.