Fiber optic gyroscope is mainly composed of fiber optic ring, light source, photodetector, and signal processing system. Its working principle is based on the Sagnac effect, which means that when a beam of light travels in a circular channel, if the circular channel itself has a rotational speed, the time required for the light to travel along the direction of rotation of the channel is longer than the time required to travel along the opposite direction of rotation of the channel. By measuring this time or phase difference, the rotational angular velocity of the gyroscope can be calculated.

Fiber optic gyroscope is an inertial sensor based on fiber optic technology, used to measure and detect rotational speed and direction.