FIELD: fiber optics; designing fiber-optic gyroscopes and other fiber sensors on base of circular optic-fiber interferometer. SUBSTANCE: circular interferometer uses auxiliary phase modulation in form of pulse succession of phase difference of beams of circular interferometer at amplitudes ±(π-Δ) and ±(π+Δ) rad formed by supply of stepped saw-tooth voltage pulses to phase modulator whose parameters are defined by figures m and n, where m and n may have any integer positive nonzero magnitudes and Δ is selected within range 0,05π rad to ≤Δ≤0,95π rad; Δ may have discrete series of magnitudes 
rad but m≥2. in this case. EFFECT: enhanced sensitivity of fiber-optic gyroscope. 8 dwg
