Intensity dependent polarisation state changes in single-mode optical fibres

The authors describe the results of their investigations into the effect of Kerr induced polarisation state changes in birefringent single-mode fibres. In the first section they describe experiments using different wavelength sources for the pump and probe, from which they have measured the value of the Kerr coefficient and investigated its temperature dependence. The second section describes self-induced polarisation state switching, which has been used to produce all optical logic elements and, under the correct conditions, can produce polarisation state instabilities