METHOD OF CONTROLLING OPTICAL SIGNAL POWER AT AN ADD/DROP NODE IN A WDM OPTICAL COMMUNICATION SYSTEM

摘要

Optical signal power levels for selected optical channels processed within an add/drop node in a wavelength division multiplexed (WDM) system are adjusted as a function of variations in signal power in an incoming WDM signal caused by gain ripple. In particular, a "ripple fitting" method is described whereby the optical signal power of individual optical channels being added at the add/drop node are adjusted to levels that correspond to the ripple profile of other optical channels being routed through the add/drop node. In this manner, the gain ripple in the WDM signal being output from the add/drop node approximately corresponds to the gain ripple i n the incoming WDM signal at the node.