Abstract: The invention provides a method of balancing the power level of an optical signal within an aggregate of optical signals in an amplified dense wavelength division multiplexing DWDM optical network, as well as power balancing apparatus therefor.

Abstract: A switching unit, equipped with a plurality of port cards and a plurality of switch cards connected in a non-parallel fashion to the port cards. Each port card has a first M-way commutator and a second M-way commutator, wherein the total number of first M-way commutators over all the port cards is N and wherein the total number of second M-way commutators over all the port cards is also N. Each switch card has a first N-way commutator and a second N-way commutator, wherein the total number of first N-way commutators over all the switch cards is M and wherein the total number of second N-way commutators over all the switch cards is also M. Each switch card further has a unit for controllably time switching a plurality of signals output by each first N-way commutator and providing a plurality of switched signals to the corresponding second N-way commutator.

Abstract: A compensator for optical transmission systems exploits gain tilt inherent in optical amplifiers. The amount of SRS induced spectral power gradient is determined, and the amplifier gain is changed to cause a compensating gain gradient in the optical amplifier to compensate for the SRS induced spectral power gradient. Fewer components are needed, and so it can be less expensive. It can be implemented as a simple software upgrade to existing systems. Many such compensators can be distributed through the system, without requiring a large inventory of individually specified filters. More accurate compensation can be achieved by making it dependent on the distribution of wavelengths within a band.