Method and apparatus for enhancing the accuracy of CRDS measurements
US7646485B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 2004 |
| Grant date | Jan 12, 2010 |
| Priority date | — |
| Expiry date | Mar 18, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/399
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for enhancing the accuracy of spectroscopic measurements using a cavity ringdown spectrometer (CRDS) is provided. A first aspect of the invention consists of a novel algorithm for the processing of ring-down data that significantly reduces the amplitude of an exponential fitting artifact, and thereby gives a better estimate of the actual loss. The primary cause of the artifact is the presence of an unwanted backwards-traveling wave that counter-propagates within the ringdown cavity. Scattering due to small imperfections at the cavity mirrors produces this wave and its intensity may be minimized by adjustment of the mirror positions during cavity construction. A second aspect of the invention consists of an apparatus for measuring the backscattered wave within a cavity to allow such cavity mirror adjustments to be made.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.