A recent change, fiber optic gyroscope, the use external and two laser beams in the opposite direction (counter - propagating) long axis (a few kilometers) of fiber optic cable, and phase difference of two beams of light through after fiber spools.
Basic mechanism, monochrome laser in the opposite path, travel and the sagnac effect, improve the FOG and gyro are the same, but the project details compared to earlier laser gyro are quite different.
Precise optical fiber coil winding must be sure that the path taken by light in the opposite direction as similar as possible.The FOG that need to be more complex than laser gyro calibration ring makes the FOG on the development and manufacturing technology of more challenging, according to the laser. FOG at low speed is not affected by the laser lock, however, need not include any moving parts, increase the biggest potential accuracy and life of the equivalent for the FOG.