Specialty Optical Fibers Handbook

Major R&D efforts have been applied to tunable fiber optic components

(compensators, attenuators, laser diodes, photodiodes, and so on) since 1997,

and these components have emerged in the commercial market. Their major

advantage is elimination of the labor (and overhead) cost of dispatching a craft

crew to the OADM and amplifier nodes at each of the remote sites each time

there is a need to change the compensation. These ‘‘truck rolls’’ are quite

expensive, and there is an increasing shortage of skilled craft persons.

Chromatic-dispersion compensation units are also needed throughout a long-

haul link, at OFA nodes, between regeneration points. Improved dispersion-

compensation techniques will allow the distance between regeneration points to

lengthen, ...