Patent ID: 8184299

Claim:
A semiconductor ring laser gyroscope comprising: a semiconductor laser for emitting two lights from both end surfaces thereof; an optical fiber ring through which the two lights emitted from the both end surfaces of the semiconductor laser propagate in respective opposite directions, and which, in association with the semiconductor laser, constitutes a laser resonator; an optical detection unit for detecting a rotational angular velocity based on beat frequencies of the two lights propagating through the optical fiber ring in the respective opposite directions; and a sensor coil made of an optical fiber wound in a multilayer manner, the sensor coil constituting a part of the optical fiber ring; wherein the optical fiber ring is structured to satisfy an expression (1): F rlg ≦10 ΔF beat — min (1) in which F rlg =C/nL, where F rlg is a ring resonance frequency, ΔF beat — min is a beat frequency corresponding to a lower limit of an angular velocity measuring range of the optical detection unit, C is a light speed, n is a refractive index of the optical fiber, and L is an overall length of the optical fiber.