A dispersion compensation system includes one or more etalons optically coupled
in series. The optical path length is used to achieves the desired dispersion compensation.
In one example, at least some of the etalons are tunable in OPL and have a non-tunable
front reflective interface. The dispersion compensation system can be tuned, for
example to compensate for different amounts of dispersion, different combinations
of dispersion offset and dispersion slope and/or manufacturing variations. In another
example, the etalons all have a non-tunable front reflective interface. The optical
path length is selected to compensate for chromatic dispersion that varies from
one wavelength channel to the next.