Fiber effects in amplified 1550-nm CATV lightwave systems

Technology has advanced to the point where externally modulated 1550-nm CW lasers and low-noise optical amplifiers are regularly deployed in commercial CATV systems. Amplified systems at 1550 nm enable longer distance transmission and higher optical powers in the fiber which have revealed both linear and nonlinear effects in fiber not seen in the 1300 nm systems. Transmission at 1550 nm is attractive for some CATV signal distribution architectures because commercial fiber optical amplifiers are available and the fiber loss is lower than at 1300 nm. The disadvantage is that nearly all installed fiber is standard single-mode with chromatic dispersion of about 17 ps/nm/km