Method, apparatus and system for cost effective optical transmission with fast Raman tilt transient control
US7446932B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2006 |
| Grant date | Nov 4, 2008 |
| Priority date | — |
| Expiry date | Jun 15, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for cost-effective optical transmission with fast Raman tilt or other transient event control uses a combination of Erbium-doped fiber amplifiers (EDFAs) and Raman fiber amplifiers (RFAs), where EDFAs are used as the primary optical amplifiers to compensate the span loss while the RFA (advantageously a forward-pumped RFA) is used only in some specific spans with a feed-forward control circuit serving as a fast Raman tilt transient compensator, the RFA also serving as an optical amplifier. A long haul optical transmission system using feed-forward controlled RFA's periodically spaced along its length, for example, when add-drop multiplexing is used, makes full use of the economics of EDFAs and the fast tilt transient control capability of a RFA enabled by an adjustable speed feed-forward or feed-back control technique. In addition, the introduced RFA also performs a dynamic gain equalization function which may eliminate the need or at least reduce the number of standalone dynamic gain equalizers which are required for an ultra-long-haul (ULH) WDM system to compensate for tilt. The invention is also applicable to the common EDFA/Raman hybrid systems and to some all-Raman sys…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.