Gyroscopes may cease spinning: Optical gyroscopes without moving parts are more reliable and more rugged than conventional mechanical systems

The optical gyro´s greater reliability, wide dynamic range, and ability to withstand high-g fields and harsh environments make it superior to mechanical gyroscopes, with their spinning rotors and complex gimballed mounts. The principle of the ring laser gyro (RLG) is explained. The engineering difficulties that had to be overcome in producing the first RLGs are described, and current research trends are surveyed.