Patent ID: 8040522

Claim:
A method for measuring a first phase difference, DeltaPhi′1(t), between a phase of a light beam in each of two light paths, and a second phase difference, DeltaPhi′2(t), between a phase of a light beam in each of two light paths, the two light paths being in a rotating interferometric fiber optic gyro, steps comprising: (a) measuring a first phase difference, DeltaPhi′1(t), due to angular velocity of the rotating interferometric fiber optic gyro over a time interval T 1 −T 0 ; (b) flipping axes of rotation of photons in the light paths of the rotating interferometric fiber optic gyro by 180 degrees, over a time interval T 2 −T 1 ; and (c) measuring a second phase difference, DeltaPhi′2(t), due to angular velocity of the rotating interferometric fiber optic gyro over a time interval T 3 −T 2 .