Cross-channel interference due to wavelength drift of tunable lasers in DWDM networks

The authors present an investigation of the wavelength stability of a tunable laser (TL) transmitter and its impact on the performance of a 2.5-Gb/s dense wavelength-division-multiplexed (DWDM) system. Performance of a DWDM system, employing such a TL, is characterized by examining the cross-channel interference caused by this drift when the channel spacing is set to 12.5 and 25 GHz. Results obtained show that the wavelength drift affects the system performance by introducing an error floor in the case of 12.5-GHz spacing. This error floor can be mitigated by increasing the blanking time of the TL during the channel transition, in order to reduce the wavelength drif