Differential absorption laser radar gas detection apparatus having tunable wavelength single mode semiconductor laser source
US5015099A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1990 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Mar 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/394
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A light source has a tunable wavelength single mode semiconductor laser. The laser outputs a single mode laser beam having a wavelength tuned in accordance with a drive current and emits, for an object to be detected, at least a first laser beam having a first wavelength which is absorbed by a gas to be detected and a second laser beam having a second wavelength which is not absorbed by the gas to be detected. A controller switches the drive current having a predetermined value corresponding to the first or second wavelength at a predetermined period and supplies the drive current to the laser and controls the drive current having the predetermined value corresponding to the first or second wavelengths so that the first or second laser beams are alternately output from the laser with substantially the same power while the first and second wavelengths are maintained. A light-receiving unit receives first and second response light components generated when the first and second laser beams emitted alternately from the laser are incident on the object to be detected and outputs electrical signals corresponding to received light amounts of the first and second response light components.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.