A ring laser gyroscope includes an optical block for generating laser beams that counter-propagate in a closed-loop type optical path, a dither mechanism for applying dither vibration for mitigating a lock-in phenomenon to the optical block, and a dither controller for controlling the dither vibration. The dither controller imparts randomness to the frequency of the angular velocity of the dither vibration.

Methods and systems for measuring low speed angular rotation of a fiber optic gyroscope. A beam of light waves is split into a first path and a second path. The light waves of the second path are directed through a fiber circulator and split into a third and a fourth path. The third path and fourth path are coupled into opposite ends of an optical fiber coil to circulate clockwise and counterclockwise. Rotation of the fiber optic gyroscope generates a phase shift between the clockwise and counterclockwise light waves, which are recombined and fed back through the fiber circulator. The recombined waves are amplified, recirculated into the second path to increase the phase shift and transmitted along the first path to an optical spectrum analyzer which generates an interferogram. A microprocessor applies an FFT, measures the spacing of frequency components, and determines the angular rotation speed of the gyroscope.