Abstract: Phase errors that occur when a dithered ring laser gyroscope enters its deadband are measured, and a correction is applied to the output of the ring laser gyroscope to compensate for these phase errors. The counterpropagating beams in a ring laser gyroscope are heterodyned to produce a pair of quadrature heterodyne signals that indicate the angular output of the laser ring laser gyroscope. The phase angle error between one of the heterodyne signals and either the sum or difference of the separate beam intensities is determined, The phase angle error signal is used to produce a control signal for adjusting the output of the ring laser gyroscope to correct for errors introduced at or near turnarounds in the dither cycle.

Abstract: A method for aligning the light path of a square ring laser gyroscope. First, the path is aligned by translation of adjacent curved mirrors which direct a light beam through a filter-like aperture. Next, the curved mirrors are translated by equal amounts in opposite directions as determined from a measurement of the non-planar condition of opposed mirror mounting surfaces.

Abstract: An apparatus and method for path length control for a laser gyro using two external gain cells and the shifted gain spectra of two neon isotopes. The laser cavity is stabilized by detecting the difference in the amplification rate between the two gain cells that are traversed by two rays. Absorption cells may be used to replace the gain cells.