The Operating Principle of FOG

The operating principle of FOGs is based on the Sagnac effect. The Sagnac effect is a universal correlation effect of light propagating in a closed-loop light path that rotates relative to inertial space. That is, two equally-characterized light beams emitted from the same light source in the same closed light path propagate in the opposite direction. Finally converge to the same probe point.

If there is a rotational angular velocity in the relative inertial space around the axis perpendicular to the plane where the closed optical path is located, then the path lengths of the light beams traveling in the forward and backward directions are different, and an optical path difference occurs. The optical path difference is proportional to the angular velocity of rotation. Therefore, as long as the optical path difference and the corresponding phase difference information are known, the rotational angular velocity can be obtained.

If you want to get more details about gyro,pls visit

For more information, please feel free to contact


Share article
Previous News
Classification and Working Principle of Accelerometer
Next News
Navigation Technology Category