Sagnac-type optical gyros

Summary The Sagnac effect is briefly presented, and passive and active interferometers are defined as ?gyros?,i.e. devices for the measurement (and control) of rotations and angular speeds. A project for the assembling and testing of an active ring gyroscope is described: the project is aimed at obtaining a versatile set-up suitable for investigation of the effects of the geometry of the laser cavity and for optimization of the gyroscope operation. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.