Method and apparatus for enhanced evanescent field exposure in an optical fiber resonator for spectroscopic detection and measurement of trace species
US7318909B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Jan 15, 2008 |
| Priority date | — |
| Expiry date | Feb 19, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/7789
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for detection and measurement of trace species in a gas or liquid sample. A sensor of a ring down cell formed from an optical fiber is exposed to the sample gas or liquid. A coherent source emits radiation into the optical fiber loop, which in turn is received at an output coupler. The fiber optic ring is coupled to a sensor which has a portion thereof, between the input and output, exposed to the sample gas or sample liquid. The sensor has an enhanced evanescent region. A processor is coupled to the receiver and determines the level of trace species in the gas or liquid sample based on the rate of decay of the radiation within the fiber optic ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.