Optical counterpart of the Foucault pendulum

Abstract

The twin beam vortex interferometer with phase-conjugating mirror in rotating reference frame is analyzed. Using the concept of the $ideal$ phase-conjugating mirror it is shown that motion of helical interference pattern may be used for detection of the slow rotations. The pattern motion is due to exchange of angular momenta between photons and interferometer. The conditions of experimental realization of such rotation sensor are discussed and $scaling$ relations for geometric parameters, coherent backscattering and angular momenta transformations are obtained.Comment: 9 pages,3 figures, submitted to referred journa