Patent ID: 7262856
Filing Date: 2007-08-28
Classification: G01N,G02B,G02F,G03H

Abstract:
1. An apparatus for remotely detecting the presence and concentration of matter in contact with a surface structure optical filter by observation of a shift in the wavelength of filtered electromagnetic waves, the apparatus comprising: a first substrate having a surface relief structure containing at least one dielectric body with at least one physical dimension smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a one or two dimensional array covering at least a portion of the surface of the first substrate; said surface relief structure being composed of or covered by a material sufficient to form a guided mode resonance filter; and a retro-reflecting structure that reflects and redirects the electromagnetic waves transmitted through the first substrate back through the first substrate in a direction substantially parallel to the propagation direction of the filtered electromagnetic waves; whereby when a sample material is deposited on the surface relief structures, an observable shift in the wavelength of the filtered electromagnetic waves is produced that is in proportion to the amount of sample material accumulated.