HYBRID RAMAN/ERBIUM-DOPED FIBER AMPLIFIER AND TRANSMISSION SYSTEM WITH DISPERSION MAP

摘要

A hybrid Raman-EDFA provides gain equalization over the C-band and L-ban d. The hybrid Raman-EDFA includes a Raman section producing a Raman gain and an EDFA section producing an EDFA gain complimenting the Raman gain. The ED FA section preferably includes a highly inverted, single-stage EDFA to produce the complimenting EDFA gain shape. One embodiment of the EDFA section includes a high return loss termination located after the erbium fiber to receive unabsorbed pump power. Multiple hybrid Raman-EDFAs can be connected in an amplifier chain in a transmission system. The transmission system preferably provides a dispersion map includi ng regular composite fiber spans followed by at least one compensating span of negative dispersion fibers. The Raman sections of the hybrid Raman-EDFAs are preferably coupled to negative dispersion fiber in the transmission system.