Novel all digital scheme for open loop fiber optic gyroscopes

Two key points which carry the information of rotation rate of gyroscopes in output wave form of open loop fiber optic gyroscopes (FOG) are found and a novel all digital detection scheme is presented. With A/D conversion, the digitized values of the key points are gotten and a control equation, with which the modulation depth of PZT modulator is stable when setting φm=4.35, and a calculation equation, from which the Sagnac phase can be worked out, are derived.