Patent ID: 6429964
Filing Date: 2002-08-06
Classification: H01S

Abstract:
An optical amplifier comprising:a preamplifier stage including a rare earth-doped gain medium and an optical pump source for generating an optical pump signal, said preamplifier stage for receiving at least one optical input signal and generating a predetermined amount of optical gain for said at least one optical input signal using the optical pump signal and providing as an output at least one preamplified optical output signal; and a power optical amplifier comprising a plurality of N concatenated output stages including an input coupled to the preamplifier stage output and an Nth output beyond the Nth output stage, said power amplifier further comprising at least one pump source coupled to either one of the power amplifier input and Nth output, each stage comprising a rare earth-ytterbium co-doped gain medium for receiving as inputs the at least one optical input signal and a pump signal, said co-doped gain medium for amplifying the at least one optical input signal in the presence of said at least one pump signal and forming an amplified output signal; and an optical power extractor coupled to the co-doped gain medium for removing a predetermined percentage Kn% of the amplified output signal therefrom and applying the remaining amplified output signal, if any, to a following stage of the plurality of N concatenated output stages.