Patent Number: 7,085,039

Title: Hybrid Raman/erbium-doped fiber amplifier and transmission system with dispersion map

Abstract: A hybrid Raman-EDFA provides gain equalization over the C-band and L-band. The hybrid Raman-EDFA includes a Raman section producing a Raman gain and an EDFA section producing an EDFA gain complementing the Raman gain. The EDFA section preferably includes a highly inverted, single-stage EDFA to produce the complementing 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 including 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.

Inventors: Foursa; Dmitri (Freehold, NJ), Nissov; Morten (Ocean, NJ), Pilipetskii; Alexei N. (Colts Neck, NJ), Mills; Michael A. (Freehold, NJ), Lin; Chinlon (Holmdel, NJ), Pedersen; Bo (Annapolis, MD)

Assignee: Tyco Telecommunications (US) Inc.

International Classification: H04B 10/12 (20060101)

Expiration Date: 8/01/02018