Detection of a substance by refractive index change
US6493090B1 · kind B1 · utility
42Cited by
9References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2000 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Dec 4, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/7746
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensitive refractive index based detector comprises a first laser cavity (7) and a second laser cavity (7′) each for generating a respective laser light beam. Each laser cavity is defined in a planar waveguide. The surface of the waveguide of the first laser (7) receives a sample to be detected. Light from the two lasers is mixed using a coupling grating (3) and a beat frequency between the lasers dependent upon the refractive index of the substance is measured at a detector (4). Extremely sensitive measurement of small quantities of substance are made possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.