Digital closed-loop re-entrant fiber-optic rotation sensor with amplified Sagnac loop

A digital closed-loop re-entrant fiber-optic rotation sensor with an amplified Sagnac loop of 20-m length is investigated theoretically and experimentally. The detection sensitivity can be increased significantly by compensating for the roundtrip loss. The linearity of the scale factor between 600 and +600 deg/s is better than 1000 ppm by using a digital closed-loop approach.