Photoionization optical filter and detector
US4879468A · kind A · utility
1Cited by
19References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 28, 1985 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Oct 28, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/1252
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical filter and detector, and a related method for its operation, in which signal photons are admitted into a detector cell and selectively excite atoms or molecules of a vapor to a selected metastable state. An illuminating laser then photoionizes a large proportion of the excited atoms or molecules, and the resulting free electrons are collected as a measure of the number of incident signal photons. The initial excitation step to a metastable state is highly sensitive to the wavelength of the signal photons and therefore acts as a narrowband filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.