Gain equalization in c+l erbium-doped fiber amplifiers

Abstract

Techniques for improving gain equalization in C- and L-band (''C+L'') erbium-doped fiber amplifier (EDFAs) are provided. For example, the C- and L-band amplification sections of a C+L EDFA may be separated and configured in a parallel arrangement or a serial arrangement. For both the parallel and serial arrangements, the C- and L-band amplification sections may share a common gain flattening filter (GFF) or each amplification section may include and employ a separate GFF. Moreover, in some examples, an ''interstage'' L-band GFF may be located before or upstream of the L-band amplification section such that the L-band optical signal is gain-equalized or flattened prior to the L-band amplification section amplifying the L-band.

Description

technical field [0001] Embodiments of the present disclosure relate to the field of optical communication systems. More specifically, the present disclosure relates to improving at least gain equalization in C-band and L-band ("C+L") erbium-doped fiber amplifiers (EDFAs) used in optical communication systems. Background technique [0002] Long-range optical communication systems, such as undersea optical communication systems, typically suffer from signal attenuation caused by various factors including scattering, absorption, and bending. To compensate for attenuation, these long-distance systems may include a series of optical amplifiers spaced along the signal transmission path and configured to amplify or enhance the optical signal in a manner that allows reliable detection at the receiver. Depending on the length of the transmission path, the number of optical amplifiers positioned along the path may vary. [0003] An optical amplifier commonly used in long-distance op...

AI Technical Summary

Problems solved by technology

While these filters do not require optical isolators (such as SP-BGF) at both the filter input and output, the disadvantage of using S-BGF and LP-GF is perhaps their physical length, which may exceed practical limits and / or or ask for more space in the repeater

Furthermore, due to the limited loss shape resolution associated with TFF (and S-BGF and LP-GF) and the limited ability to track the steep slope of the gain curve, TFF (as well as S-BGF and LP-GF) may not be able to Sufficient accuracy in equalization and especially in broadband applications such as C+L EDFA

Images