Alternative interpretation of rotation rate sensing by ring laser

Abstract

This paper deals with the laser rotation rate sensor, sometimes also referred to as laser gyroscope, which was most extensively investigated by Macek and co-workers at Sperry Gyroscope. The function of rotation sensing is first discussed for a ring resonator of circular shape. It is seen that in that case the standing wave electromagnetic energy distribution remains stationary while the cavity structure with an attached detector is rotated so that the detector samples standing waves. Thus, rotation sensing is linked with the fact that Maxwell's equations are valid for inertial reference frames or equivalently, with the inertial nature of electromagnetic radiation. The concept of inertia is then used to derive the ring laser equation for arbitrary ring shape. It is hoped that these viewpoints offer a more elementary understanding of rotation sensing through ring lasers than other available derivations.