FIBEROPTIC GYROSCOPES WITH DEPOLARIZED LIGHT

Experimental observations of pi-bias phase shifts causing an inverted interference fringe have been made in fiber gyros using depolarized light and ordinary fiber. These observations are accounted for by a four parameter birefringence model representing the gyro coil which explicitly accounts for polarization mode mixing in the interior of the coil. The addition of a Lyot depolarizer to the coil is shown to remove all birefringence induced effects and to provide a constant scale factor.