Adjustable chromatic dispersion compensator

摘要

A system for individually controlling the chromatic dispersion of one or more wavelength division multiplexed (WDM) optical signals, the system comprising chromatic dispersion compensation means comprising a plurality of individually controllable differential optical delay elements. An example of a suitable differential optical delay element is a tunable fibre Bragg grating filter whose spectral response varies along the length of the grating, i.e. is chimed in a non-linear fashion. The system may, in addition, comprise one or more second individually controllable differential optical delay elements arranged so as to compensate for any unwanted delays across the wavelength band of a signal introduced by a first delay element. Optical circulators may be used to route signals into and between the pluralities of differential optical delay elements. This system has the advantage of providing a compact multi-channel selective differential delay means suitable compensating for chromatic dispersion in a WDM optical communications network.