Abstract: An optical system uses a nonlinear optical medium to alter the frequency of a relatively narrow band light source tunable over a plurality of different frequencies using an optical system for passively directing light to the nonlinear medium at a correct phase matching angle. In this manner, the light from the tunable light source can be efficiently frequency-doubled or frequency-tripled without the need of moving parts. An all prism design provides a system of optimal efficiency.

Abstract: An optical system for efficiently directing a large bandwidth light (e.g., a femtosecond laser pulse) onto a nonlinear optical medium includes a plurality of optical elements for directing an input light pulse onto a nonlinear optical medium arranged such that the angle .theta..sub.in which the light pulse directed onto the nonlinear optical medium is substantially independent of a position x of the light beam entering the optical system. The optical system is also constructed such that the group velocity dispersion of light pulses passing through the system can be tuned to a desired value including negative group velocity dispersion.

Abstract: The assay of the subject invention uses DNA sequences as probes in a nucleic acid hybridization diffraction assay, to detect specific DNA sequences in a sample. Diffraction assay methodologies are applied to determine the presence and amount of analyte.This invention involves a discovery in the areas of supporting surfaces for a biogrid or biograting which provide greatly reduced non-specific hybridization and binding. A preferred process of this invention involves manufacturing a biograting for use in a light diffraction assay, and comprises adhering a uniform layer of hybridizing reagent comprising a nucleotide sequence on a smooth, solid surface and exposing the surface to UV radiation through a shadow mask with a diffraction grating pattern of lines to selectively deactivate the hybridizing reagent, leaving a biological diffraction grating design of lines of active hybridizing reagent.

Abstract: An improved binding assay plate having greatly reduced non-specific binding with proteinaceous reagents comprising a polysilicon surface having a binding reagent adhered thereto, the surface having a coating adsorbed thereon of a proteinaceous non-specific binding inhibitor. This binding assay product is prepared by adhering binding reagent to a polysilicon surface and then treating the surface with the proteinaceous non-specific binding inhibitor.The binding assay method comprises the steps of contacting the polysilicion surface having a primary binding reagent and non-specific binding inhibitor adhered to the surface thereof with a solution containing an analyte with which the primary binding reagent specifically binds for a time sufficient to permit conjugation of analyte with the primary binding reagent and determining the analyte bound to the polysilicon surface. The plate is suitable for both sandwich and competition immunoassays.

Abstract: A diffraction immunoassay method in which a diffraction grating design of non-light disturbing primary binding reagent on an insoluble surface is conjugated with analyte in a sample. If the primary binding reagent-analyte conjugate is light disturbing, a diffraction grating is formed. If the primary binding reagent-analyte conjugate is non-light disturbing, the analyte is further conjugated with a secondary binding reagent which is labeled with a light disturbing material to form a diffraction grating. Light from a narrow band light source is then applied to the surface, and the intensity of beams of diffracted light formed by the diffraction grating is determined. The diffraction immunoassay plate for the method comprises a smooth insoluble surface having on the surface thereof, a diffraction grating design of lines of the primary binding reagent.