Twin fiber grating tunable dispersion compensator

A new tunable dispersion compensator that does not suffer from higher order dispersion is reported. The device consists of two quadratically chirped fiber Bragg gratings, each with linear strain actuators. The module has a tuning range of 500 ps/nm and a bandwidth of 0.5 nm. In a 40-Gb/s return-to-zero system, the dispersion penalty tolerance is extended from 100 to 600 ps/mm.