Line-locked diode laser for gas spectroscopy
US5930000A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1998 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Feb 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/031
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method are disclosed for measuring the concentration of gases that are unstable or difficult contain in a sample cell. A frequency modulated laser is tuned to the frequency of a first spectral feature of a gas of interest and a laser beam is projected through a reference cell containing, at a selected pressure, a selected second gas that has a second spectral feature near the first spectral feature of the gas of interest. The laser is line-locked to an outer zero crossing of a third harmonic of the detected laser beam coincident with the first spectral feature. The concentration of the gas of interest is calculated from a second harmonic of a portion of the laser beam projected through a transmission medium containing the gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.