KERR EFFECT IN OPTICAL PASSIVE RING-RESONATOR GYROS.

The optical passive ring-resonator gyro (OPRG) has been studied for its potential to reduce the length of the sensing loop and to realize a wide dynamic range. In this paper, the Kerr effect in the OPRG is newly analyzed taking account of the optical source coherence. It is clear that this effect can cause a drift greater than the shot-noise limit we discussed previously, especially for a higher coherence source. A low coherence optical source can be successfully adopted in a fiber gyro to reduce the Kerr effect noise but that cannot be used for an OPRG. The method of eliminating this drift is also discussed.