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:
Apr. 28, 1987
Filed:
Oct. 02, 1985
John R Haavisto, Scituate, MA (US);
Northrop Corporation, Los Angeles, CA (US);
Abstract
Passive ring resonator laser gyro. The gyro eliminates the need for separate frequency control devices for the two counter propagating beams. A semiconductor laser diode, the source, is switched between two frequencies and its output is coupled into a branching waveguide. The light in the waveguide is coupled into a resonant ring waveguide and then sampled by detectors. The laser current is switched at a fixed rate between two values. The values are selected such as to cause the laser output to switch between the resonant frequencies of the two directions of propagation in the ring. These values are determined by a resonance tracking servo. The disclosed laser gyro eliminates the need for active frequency controlled devices in the waveguide structure resulting in less noise, better signal, and reduced cost.