The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 20, 1983
Filed:
Jan. 12, 1981
Giovanni Busca, Neuchatel, CH;
Leland Johnson, La Chaux-de-Fonds, CH;
Oscilloquartz S.A., , CH;
Abstract
The atomic frequency standard comprises a source of light of a given spectral component, comprising a lamp 2 and an isotopic filter 3. The light arriving in an Rb 87 cell 4 empties the hyperfine level F=1 by optical pumping. Microwave excitation produced by a loop 5 causes the atoms which populated the level F=2, m.sub.F =0, to fall back to the level F=1, m.sub.F =0. Filling of the latter level reduces the transparency of the cell 4, which phenomenon is detected by a photoelectric cell 6 and permits tuning of the microwave excitation to the hyperfine transition frequency. The electromagnetic wave produced by the loop 5 is progressive, which, by the Doppler effect, increases the width of the absorption line of the cell. This increase makes it possible to reduce the control time constant and consequently makes it possible to have a compact frequency standard, with a rapid control action, which can operate in an unfavorable environment.