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:
Jan. 31, 1995
Filed:
Oct. 28, 1987
Graham J Martin, Canoga Park, CA (US);
Litton Systems, Inc., Beverly Hills, CA (US);
Abstract
A ring laser gyroscope uses a lasing-mode suppression technique to circumvent frequency locking rather than more common frequency biasing methods. The device operates with a four-mirrored nonplanar optical path that allows left and right circularly polarized, on-axis modes to lase in each direction when an included gaseous gain medium is electrically discharged. A uniform axial magnetic field is applied to the gain region in order to produce a splitting of the gain curve into two parts separated in frequency by the cavity free spectral range. By small adjustments to the cavity length the two gain curves are centered about consecutive cavity longitudinal mode sets, each consisting of four modes. Consequently only two modes from each set can lase, thus creating a four-mode ring laser gyroscope with arbitrarily large lasing mode frequency spacings controlled primarily by the cavity geometry. The device may be configured to operate with a single isotope of neon in the gain medium. A simple magnetic field servo mechanism provides a high degree of immunity to external magnetic field charges.