Externally modulated lightwave CATV transport systems employing negative dispersion fiber

An externally modulated AM-VSB CATV transport system in the 1550nm region using negative dispersion fiber (NDF) as the transmission medium is proposed and successfully demonstrated. Good performances of carrier-to-noise radio (CNR), composite second order (CSO) and composite triple beat (CTB) were achieved over an-80km NDF transmission without dispersion compensation. Externally modulated transmitter has a positive residual Mach-Zehnder modulator (MZM) chirp; but, NDF has a negative dispersion property in the transmission fiber. This negative dispersion property overcomes the positive frequency chirp and results in system with better transmission performance.