Abstract: Methods and apparatus for a scuttle assembly including an end member having a port to enable fluid flow, a valve member having a closed position to prevent fluid from flowing into a channel and an open position to allow fluid flowing into the channel, a bias member to bias the valve member to the open position, and a scuttle washer sandwiched between the end member and the valve member, the scuttle washer comprising a material that dissolves due to exposure to sea water without generating toxic gas or hydrogen.

Abstract: Methods and apparatus for a scuttle assembly including an end member having a port to enable fluid flow, a valve member having a closed position to prevent fluid from flowing into a channel and an open position to allow fluid flowing into the channel, a bias member to bias the valve member to the open position, and a scuttle washer sandwiched between the end member and the valve member, the scuttle washer comprising a material that dissolves due to exposure to sea water without generating toxic gas or hydrogen.

Abstract: A ring laser gyroscope having apparatus for compensating a gyroscope output signal for optical power variations in accordannce with variations of a dihedral frequency. A scaler quantity is determined based on operational data and it is used to compensate the gyroscope output signal. Alternatively, a gyroscope output signal is compensated via a feedback network by adjusting the gain medium in the laser gyroscope in accordance with variations in the dihedral frequency.

Abstract: A ring laser gyroscope having a self-compensating discharge path between a single anode and cathode which comprises equal segments in the laser path in series with a channel that interconnects the laser path and allows a single current to flow within the equal segments in opposite directions with respect to the laser beam thereby cancelling the Fresnel-Fizeau drag effect. This design is applicable also to laser gyroscopes having two or more rings in a single gyro block structure.

Abstract: A laser gyroscope having a multi-frequency ring laser resonator containing a gas laser energized by electric discharge through a gaseous laser medium from two anodes to a common cathode positioned outside the lasing passage and communicating therewith through a narrow bore having a nonuniform constant magnetic field applied to the gaseous discharge in said bore to suppress high frequency gas discharge oscillations in the laser.

Abstract: A four frequency laser gyroscope system having parallel processing of path length control and detection signals. Two output signal beams each containing components of two of the four waves circulating in the laser cavity are shone upon separate detector diodes. The output signals from the diodes contain both high and low frequency components which are separated in a crossover circuit. The low frequency component is processed to control the optical path length while the high frequency component is processed to produce a digital signal representing the amount of rotation of the laser gyroscope cavity.