Influence of transmitter chirp on optimised dispersion managed 10 Gbit/s NRZ installed links

The impact of transmitter chirp on the performance of pre- and post-compensation normalised sections for non-return-tozero single channel systems was studied by computer simulation. An acceptable dispersion and power margins in typical 10 * 80 and 20 * 80 km-long terrestrial transmission systems were found at 10 Gbit/s. Positive transmitter chirp can remarkably increase the optimised Q-factor of a pre-compensated scheme, increase the acceptable range of the dispersion compensation ratio for a prescribed Q-factor, and shift the optimum power levels toward higher values. However, no significant improvement results from using chirp for the post-compensated scheme. By independently varying the power at the transmission and compensating fibres inputs and the dispersion compensation ratio, the post-compensation scheme shows better performance than the pre-compensation scheme at the expense of stricter parameter tolerance.