Long-haul terrestrial optical fiber link having low-power optical line amplifiers with integrated dispersion compensation modules

摘要

The present invention provides an improved terrestrial optical fiber communications network link including an increased number of amplification sites spaced at intervals along the link in series with shorter optical fiber spans. One embodiment of the invention includes an improved long-haul terrestrial optical fiber link having low-power line optical amplifiers (LPLAs) at the amplification sites connected together by optical fiber spans. In other embodiments of the present invention, some or all of the LPLAs have integrated dispersion compensation modules (DCMs). Another embodiment of the improved optical fiber link system uses proper adjustment and spacing of LPLA amplifiers (e.g., spaced between 30-60 km long fiber spans) to eliminate the need for lightwave regenerators (LREs) even along very long (e.g., 300-2500 km long or even longer) links. The long-haul optical link is transparent to wavelength or combination of wavelengths in the erbium band, and any combination of modulations applied to those wavelengths. The long-haul terrestrial optical fiber link of the present invention has several differences from the traditional optical fiber links. Low-power line amplifiers (LPLAs) of the present invention differ in several ways from bi-directional line amplifiers (BDLAs). The low-power line amplifiers of the present invention also differ from submarine amplifiers.