Patent ID: 7453576

Claim:
A method for calibrating a fiber optic gyroscope comprising: propagating first and second portions of light from a first light source through a fiber optic line in respective first and second directions; determining a first voltage operable to cause a predetermined phase shift between the first and second portions of the light from the first light source; applying the first voltage to a modulator to cause a first phase shift between the first and second portions of the light from the first light source; determining a first phase shift between the first and second portions of the light from the first light source; propagating first and second portions of light from a second light source through the fiber optic line in the respective first and second directions; determining a second voltage operable to cause the predetermined phase shift between the first and second portions of the light from the second light source; applying the second voltage to the modulator to cause a second phase shift between the first and second portions of the light from the second light source; determining a second phase shift between the first and second portions of the light from the first light source; and determining a difference between the first voltage and the second voltage.