Characteristic features of the effects of the polarisation nonreciprocity of fibre ring interferometers

The Jones matrix method is used to derive and analyse expressions for the nonreciprocal phase difference between counterpropagating waves, associated with the polarisation effects in a fibre ring interferometer. The conditions necessary for the observation of the polarisation nonreciprocity are identified and the difference between this and other nonreciprocities is considered. Several interferometer systems exhibiting nonreciprocal effects, in particular an interferometer with a ring loop formed from a single-polarisation fibre, are discussed.