Method and system for automatic gain equalization in an optical transmission system using WDM technique

摘要

It is disclosed a method and system for automatic gain equalization in a WDM optical communication system, which provides for using Automatic Gain Equalizers to pre-tilt the spectrum and get both gain flattening and Optical Signal to Noise Ratio flattening: the AGEs are periodically inserted in the amplification chain, for pre-compensating the tilt that will accumulate down the line (pre-emphasis). Optical Spectrum Monitors are placed some amplifiers downstream, measure the OSNR and send this data back to the relating AGE. For each wavelength the difference between the OSNR and the minimal OSNR over the spectrum is computed and added to the previous attenuation at this wavelength. The new attenuation spectrum is normalized and is used to control the AGE.