Abstract

Passive optical gyros were believed to be devoid of the lockin effect observed in (active) ring laser gyros. The passive cavity gyro proposed by Ezekiel and Balsamo is one such concept in which electronic servo loops perform the resonance frequency tracking function. It was pointed out in Ref. 1 that the notion of resonance frequency tracking leads to the lockin effect. In Ref. 2 observation of such lockin effect was reported and various means to circumvent it were suggested. We have measured the lockin rates of twenty ring laser gyros in both passive and active modes. A computer-controlled station was developed for these experiments that measures the passive lockin rate of the test gyro. By measuring the random walk of the same gyro in the active mode its active lockin rate was obtained.

© 1991 Optical Society of America