The phase-modulated optical fiber gyroscope signal was analyzed in a time-domain. The rotation rate detected by the gyroscope optics was extracted from the gyroscope signal as time-domain characteristics at the maximum sensitivity.

A down sampling technique was applied to signal processing for optical fiber gyroscopes. It lowered the higher speed requirement for the sampling system and numerical operations. Utilizing the technique, a digital signal processing circuit extracted rotational information from the gyroscope signal.

Secondary phase modulation was proposed for lowering the signal frequency band of open-loop optical fiber gyroscopes. Extracting the lowered frequency spectra, the rotation rate was derived from the gyroscope signal and the drift in the optical parameters were compensated.