Fiber-Optic Rotation Sensors

Fiber optic inertial frame rotation sensors based upon the Sagnac Effect offer the possibility of advantages in production cost, operating lifetime and performance over traditional spun mass and non-waveguide laser gyro's. A number of design approaches are possible which fall broadly into the two categories of single and dual-frequency inter ferometers. A feature in common to all is the need to control the relative phase of the counter-propagating waves at certain points within the sensors by introducing a nonreciprocal phase bias. This paper discusses the family of possible design approaches.