Sagnac fiber-ring interferometer gyro with electronic phase sensing using a (GaAl)As laser

Rotation-sensitive fiber-ring interferometers have been demonstrated using balanced heterodyne phase-detection techniques. Red He/Ne and infrared (GaAl)As lasers were employed with balanced elasto-optic frequency shifters as sources. Rotation-induced phase shift (Sagnac effect) was demonstrated using both single-mode and multimode low-loss fibers.