Sagnac effect in fiber gyroscopes

Abstract

We review the kinematic explanation of the Sagnac effect in fiber gyroscopes and recall that the index of the dielectric medium does not have any influence. Furthermore, we present a novel electrodynamic approach that confirms in more detail that the Sagnac phase shift of a ring-waveguide interferometer is the same as for the original Sagnac experiment with plane waves in a vacuum.