Correlation of the long-term performance fluctuation in 5 Gb/s, 2 WDM system

The long-term stability of the system performance is quite important to realize the practical system. In the long distance amplified lightwave system, the small fluctuations, such as polarization dependent gain and so on, cause the performance instability. In this letter, we report, for the first time, simultaneous performance measurements in the two-channel system operating at 5 Gb/s. It is shown that the correlation factor of the performance between the channels is described as a function of the channel separation.