APPARATUS FOR DISPERSION COMPENSATING A SIGNAL THAT PROPAGATES ALONG A SIGNAL PATH

摘要

Apparatus for dispersion compensating a signal ( 18 ) that propagates along a signal path ( 19 ), which apparatus comprises a grating ( 1 ) and a tuning means ( 2 ). The grating ( 1 ) is characterized by a wavelength operating range ( 3 ) and a group delay ( 4 ) that varies with wavelength ( 5 ), wherein the group delay ( 4 ) is equal at a plurality of pairs of wavelengths ( 6 ), ( 7 ) that are separated within the wavelength operating range ( 3 ), and wherein the grating ( 1 ) reflects each wavelength pair ( 6 ) from the same region ( 8 ) of the grating ( 1 ), and different wavelength pairs ( 7 ) from different regions ( 9 ) of the grating ( 1 ).