Passive frequency standard
US4947137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Feb 28, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The passive frequency standard of this invention comprises a cell (42) containing Rb87 and a source of predetermined spectral component which, by optical pumping, empties the level F=1, m.sub.F =0 and populates the level F=2, m.sub.F =0. This source comprises a lamp (40) and an isotopic filter constituted by Rb 85 contained in the cell (42). A helicoidal resonator (44) is tuned to the transition frequency between level F=2, m.sub.F =0 and level F=1, m.sub.F =0. It receives an excitation signal for stimulating such transition from an oscillator via a connector (64). The frequency of the oscillator is slaved to the transition frequency by slave means comprising a photoelectric cell (46) which receives the light from the lamp (40) through the cell (42).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.