Practical method for eliminating the magnetic bias sensitivity of square ring laser gyros by adjusting the nonplanar angle

In order to eliminate the magnetic bias sensitivity of square ring laser gyros, a novel practical method by adjusting the nonplanar angle of a ring resonator in the assembly process has been proposed. The ratio coefficient of the magnetic bias sensitivity to non-planarity has been obtained experimentally for the first time and it is found to be almost constant for this kind of square ring laser gyros. This result is useful for the practical elimination of the magnetic bias sensitivity. The magnetic bias sensitivity of every square ring laser gyroscope can be reduced to near zero with the novel method theoretically and it is proved experimentally. These findings are extremely useful for the research on super high precision ring laser gyroscopes.