On the dragging of the plane of polarization of light propagating in a rotating medium

The rotation of the plane of polarization of light propagating along the axis of rotation of a rotating dielectric medium, as recently measured by Jones (1976), is examined by means of the usual formalism of the electro-dynamics of a moving medium. The treatment goes beyond that of Fermi (1923) in including the effects of dispersion. It is found that the optical rotation includes a 'dragging coefficient' $(1/n_{\phi})(n_{\text{g}}-1/n_{\phi})$ (where $n_{\text{g}}$ and $n_{\phi}$ are the group and phase refractive indices of the medium respectively) equal to that found for 'aether drag' in the transverse case or in the longitudinal case for a fluid medium with fixed boundaries.