40 Gbit/s 1.55 [micro sign]m RZ transmission over 109 km of non-dispersion shifted fibre with long continuously chirped fibre gratings

Abstract
The authors report the first demonstration of 40 Gbit/s transmission over 109 km of standard fibre at 1.55 µm with dispersion compensating linearly chirped continuous fibre gratings and a ~0.5 nm source wavelength tolerance, demonstrating the feasibility of fabricating such gratings for use at very high data rates.