Method of excitation of an optical cavity for detecting gas traces
US6504145B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2000 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Oct 30, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/39
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention concerns a method for detecting gas traces with a semiconductor laser coupled with an optical resonant cavity containing a species to be analyzed. The laser is coupled with the cavity so that the light is not projected back towards the laser when the cavity is in resonance mode. The laser supplies an amplified and fine-tuned emission on the re-injected frequency and, when a current pulse is applied thereon, its frequency moves from a predetermined initial frequency to a final predetermined frequency. The laser is excited by a first current pulse such that its frequency is sequentially locked on the cavity successive modes. The luminous intensity decreasing time in the cavity is measured at the end of the pulse and the excitation and measurement steps are repeated for successive current pulses, to cover a spectral range to be analyzed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.