Resources Contact Us Home
Solid medium optical ring laser rotation sensor

Image Number 3 for United States Patent #5408492.

An optical rotation sensor comprises a light amplification stimulated emission ring laser formed in a solid medium is provided with phase modulator devices which produce push-pull phase modulation of counterpropagating optical waves in the ring thereby enhancing bidirectional lasing in single longitudinal modes in each direction. A frequency selective output coupler couples a predetermined portion of the optical energy at the lasing frequency from the ring to an output waveguide. A substantially U-shaped output waveguide having legs extending away from the ring in opposite directions and toward a common position. Clockwise and counterclockwise light waves are coupled from the ring to the two separate legs of the output waveguide and are directed to the common position to create an interfering light pattern on photodetector apparatus. The interfering light pattern is indicative of the rate of rotation, as defined by the Sagnac effect. Signal processing circuitry connected to the detector derives navigation and flight control information from the detector. In one embodiment, the ring laser and input and output couplers are implemented in a rare earth-doped lithium niobate substrate. In another embodiment, the ring laser and the input and output waveguides are implemented in rare earth-doped optical fibers. In a further embodiment, the ring laser and input and output couplers as well as the phase modulators and the photodetector apparatus are implemented in a single semiconductor substrate and gain electrically supplied to the ring laser.

  Recently Added Patents
Semiconductor apparatus
Reovirus for the treatment of cellular proliferative disorders
Scaleable status tracking of multiple assist hardware threads
Computer network running a distributed application
Inflatable workshop
Resonant conversion system with over-current protection processes
Architecture for accelerated computer processing
  Randomly Featured Patents
Positive temperature coefficient polymer composition and material made therefrom
Electromagnetic devices
Light sword toy with moving internal object
Method of, and apparatus for, changing bobbins in automatic winders
Dielectric layers and methods of forming the same
Method for separating solder and solder oxides
Disk brake with a parking brake function
Selective personality negotiation during session negotiation
Method for planarized isolation for CMOS devices
Combined pacifier cover and retainer