An optical device including an optical amplifier to amplify optical signals received through an optical input, and to supply the amplified optical signals from an optical output, and an optical filter component to compensate for variations in the gain spectrum of the optical amplifier that occur as a...http://www.google.ca/patents/US6545798?utm_source=gb-gplus-sharePatent US6545798 - Thermal ripple-compensating, gain-flattening filter for an optical amplifier
