Fibre-equaliser second order distortion compensation in 1.55 mu m lightwave CATV transmission system

Optical equalisation of CSO degradation induced by laser chirp and standard fibre dispersion is experimentally demonstrated. This equalisation is based on the combination of the standard singlemode fibre with a large negative dispersion fibre. With a 10 km standard fibre span the optical fibre equaliser allows the degraded CSO to be reduced back to the value of the intrinsic laser CSO. A shorter standard fibre span for loop distribution was also compensated by using this technique. The linear behaviour of the optical fibre equaliser is demonstrated.