The present invention provides an
optical amplifier pre-emphasis and
equalization method that alleviates the
optical amplifier gain ripple penalty experienced in conventional optical communications systems. This method includes storing measured communications channel
signal gain ripple information, acquired during factory calibration, in the
internal memory of each
optical amplifier module. When the optical amplifiers are assembled into a chain,
system software retrieves this communications channel
signal gain ripple information from each optical
amplifier module and computes the pre-emphasis or
equalization required for each channel in order to obtain a flat SNR at a
receiver. The method also includes measuring the ambient temperature of each optical
amplifier module and applying a correction based on the expected change in gain response of each optical
amplifier. The method further includes, for
Raman amplifiers and the like, applying a
fiber type,
gain setting, GFF error, etc. correction based on the expected change in gain response of each optical amplifier. The method relies on using VOAs at the sources or DGEs / RBFs in the optical
signal path to pre-emphasize or equalize the optical channels.