Abstract

The residual facet reflectivities and high gain of a traveling wave optical amplifier (TWA) give rise to a significant amount of gain ripples on top of the gain curve. In lightwave communication systems with data rates in excess of 10 Gbit/s, both the information bandwidth of the signal and the chirp spectral width of the laser could be comparable to the period of the gain ripples. In these conditions, different portions of a data stream could encounter drastically different optical gains when they pass through the amplifier, thus resulting in a significant amount of intersymbol interference and an extinction ratio penalty. We found that at 11 Gbit/s, severe system degradations occur as the gain ripple increases and complete eye closure results in the worst case.

© 1990 Optical Society of America