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. 08, 1989
Filed:
Jun. 08, 1987
John L Hall, Boulder, CO (US);
Miao Zhu, Boulder, CO (US);
University Patents, Inc., Westport, CT (US);
Abstract
The disclosure is directed to a method and apparatus for precisely controlling the frequency of a laser, and for precise control of distance. In a disclosed embodiment, a laser beam is split, modulated to obtain a frequency differential, and coupled to an interferometer which is designed to produce two processed beams having intensities that vary at the same ac frequency, but at a phase difference that is indicative of the laser frequency. The processed beams are converted to ac electrical signals which are coupled to phase control circuitry. The phase control circuitry determines the phase between the electrical signals and produces a control signal for controlling the laser frequency. Phase offset increments are introduced in the phase detection process, these phase offset increments resulting in controlled changes in the laser frequency. The laser frequency can be computed and read out as a function of the phase offset increments. In another embodiment, the control signal is used to accurately control a distance.