METHOD OF REDUCING POLARIZATIN VARIATION INDUCTION DRIFT IN RESONANT OPTICAL FIBER GYRO AND DEVICE APPLYING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a method of preventing the error in the output of a resonant optical fiber gyro even when the loss of the polarization dependency exists in a ring resonator at a coupler or lead part in a resonant optical fiber gyro, and to provide a device applying the method. SOLUTION: In the ring resonator, the difference in lengths L1 and L2 of two parts of a wave guide path divided at a point of the rotation of the polarization with the coupler 1 isΔL. The difference in propagation constant of two polarization shafts of the wave guide path isΔβ. The relationship ofΔL andΔβisΔβΔL=π+2nπ[rad] (n: integer) or a value at the neighborhood of the same. TheΔL is determined to minimize the error induced by the polarization variation. Whereby the ring resonator itself can be brought into a state free from the error, and the resonant optical fiber gyro can minimize the error of the gyro output induced by the polarization variation.