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:
Aug. 15, 1995
Filed:
Sep. 09, 1994
Irving Liberman, Squirrel Hill, PA (US);
Westinghouse Electric Corporation, Pittsburgh, PA (US);
Abstract
The wavelength of light generated by a diode laser optically pumping vapor in the gas cell of an atomic time-standard is stabilized against variations in ambient temperature by application of pressure to the semiconductor laser by a piezoelectric transducer, preferably implemented as thin films on the diode structure. Closed loop control of the pressure is provided by feeding back a detector signal, which is a measure of light transmitted through the vapor, to a null seeking servo the output of which is converted to a control signal which is a function of temperature/pressure. The control signal, which is applied to the piezoelectric transducer, which in turn is preferably implemented as a thin film on the diode structure, can be dithered to sense and maintain the desired resonant atomic transition frequency. The vapor is additionally excited by a microwave signal locked to an atomic transition frequency through feedback of the detector signal.