Key points are not available for this paper at this time.
Mimicking the description of spinning particles in General Relativity, the Fermat Principle is extended to spinning photons. Linearization of the resulting Papapetrou-Souriau type equations yields the semiclassical model used recently to derive the ``Optical Hall Effect'' for polarized light (alias the ``Optical Magnus Effect'').
Duval et al. (Fri,) studied this question.