Substrate index modification for increasing the sensitivity of grating-coupled waveguides
US6985664B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 2003 |
| Grant date | Jan 10, 2006 |
| Priority date | — |
| Expiry date | Oct 13, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/7743
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A grating-coupled waveguide (GCW) and a method are described herein that can be used to detect the presence of a biological substance (e.g., cell, drug, chemical compound) in a sensing region of the GCW. The GCW includes a substrate, a diffraction grating and a waveguide film that has a higher index of refraction than the substrate which has an index of refraction≦1.5. The relatively low-index substrate effectively increases the sensitivity of the GCW by causing the waveguide mode to shift towards a biological substance located in a sensing region above the waveguide film, thereby increasing the field strength of the mode's evanescent tail in this region. In one embodiment, an array of the GCWs are incorporated within the wells of a microplate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.