Diffraction anomaly sensor having grating coated with protective dielectric layer
US5925878A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1997 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | Aug 20, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/553
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for optically assaying a targeted substance in a sample using a diffraction anomaly grating sensor. The optical sensor has a diffraction grating coated with at least one dielectric layer such that the sensor is sensitized to interact with the targeted substance. Upon interaction, light incident upon the sensor at a particular angle propagates through the dielectric, thereby exhibiting a dip in zero-order reflectance. Advantages of the present invention include facilitating increased sensitivity while protecting the metal grating from tarnishing and degradation. The present invention also allows for the construction of sensors that are sensitized to a plurality of substances, thus eliminating the need for an operator to reconfigure the sensing system in order to assay different substances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.