Patent ID: 7198901

Claim:
A system for analyzing a sample for the presence of specific targets in a biochip while eliminating major background emissions, which system comprises: a biochip that includes a flat optical mirror surface which reflects incident excitation and/or emission photons, one or more transparent dielectric layers coating said mirror surface, and a plurality of three-dimensional domains attached to an exposed surface of said dielectric layer yielding detectable photon energy corresponding to the presence of analyte distributed throughout the domain as a result of spontaneous emission, scattering or other mechanism, each domain being of a thickness equal to or greater than about one-half of an optical emission wavelength of said photon energy, and an optical detection system that is adapted to quantify the presence of analyte in each domain by measuring or imaging photons associated with each analyte domain, said dielectric layer or layers having a thickness which is approximately N/2 wavelengths, where N is any integer greater than 0 and a refractive index such that, for a set or range of reference wavelengths, net destructive interference occurs for at least one of the following conditions at the exposed surface of the dielectric: i. for incident excitation light energy, destructive interference occurs between radiation propagating toward the mirror through the dielectric and reflected excitation radiation propagating away from the mirror, and ii. for light energy emitted via spontaneous emission, scattering or other process occurring at about the exposed dielectric layer surface, destructive interference occurs between wavefronts emitted or scattered toward the direction away from the mirror and wavefronts emitted or scattered toward the mirror and reflected by the mirror, whereby, for any sources of potential background photon contamination at the plane of said exposed surface, net destructive interference occurs at the set or range of reference wavelengths thereby diminishing any such contaminant optical signal.