POL, skew is an important problem, limiting the maximum data-rate of parallel transmission.
is generated by:
–the optical converters,
–the integrated electronic circuits, and
–the optical fibre (in this case fortunately SM)
ribbons, skew is mainly generated by variations of the reflection index, close to 1.5, between the fibres. Indeed, speed of transmission in the fibre is in
function of its reflective index.
have thus asked BICC for ribbon fibre where each of the 8 fibres was drawn from the same bath. Very little change is now expected in speed of propagation between the different fibres of the ribbon.
remained unchanged, no extra manipulations were needed during the fabrication process.