Temperature Dependence of PMD in Optical Fibres and Cables: Part II

Following experiments on temperature dependence of polarization mode dispersion (PMD) of in tight-buffered standard single mode fibres (ITU-T G.652), see Ibid., pp. 441-444, we did the same for nonzero-dispersion shifted fibres (NZ-DSF, ITU-T G.655), and found they exhibit much better PMD stability when subjected to mechanical forces generated by buffers and coatings. The difference can be explained by "spinning" during drawing of NZ-DSF fibres, leaving residual circular strain, which rotates radiation polarization plane, preventing accumulation of DGD in a fibre under axial and lateral pressure. Mechanical twist, e.g. due to stranding of fibres to make multi-fibre optical unit has the same effect. We also review other factors influencing PMD performance and stability of fibres encased in tight and semi-tight buffers, predominantly used in indoor, industrial and military cables