Upgradable, gain flattened fiber amplifiers for WDM applications
AssigneeSDL, Inc.
InventorsPaul N. Freeman, Stephen G. Grubb, Daniel A. Ratoff, David G. Mehuys
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Abstract
A multistage optical fiber amplifier (OFA) system is designed to be upgraded with the addition of pump power when signal capacity of an optical communication link is correspondingly increased. The system includes a gain flattening filter (GFF) that remains valid when the system is upgraded because of the system design. Also disclosed are ways to enhance the GFF as well as control the channel signal gain tilt as well as adjust the external gain uniformity to be the same for an assembly line of OFA systems.
Claims16
A multistage fiber amplifier system comprising:
- an input amplifier stage and an output amplifier stage each comprised of a rare earth doped fiber and each having an inherent gain profile over a given gain spectrum, said input amplifier stage receiving an input comprising a plurality of channel signals for amplification and together having a given input signal power;
- a first plurality of pump laser sources with outputs combined for providing pump power to said input and output amplifier stages;
- the combined pump outputs being split to pump the input and output amplifier stages;
- and
- upgradable pumping power provided to said input amplifier stage and said output amplifier stage to increase the pump power to said amplifier stages for maintaining the rare earth inversion levels and gain profiles in said amplifier stages when said input signal power to said input amplifier stage is increased or when an amount of signal channels provided to said input amplifier stage is increased.
The multistage fiber amplifier system of 1 wherein excess pump power provided to said input amplifier stage is launched into a first portion of said output amplifier stage and a second portion of said output amplifier stage is provided with pump power via said pump split to pump the input and output amplifier stages.
Dependencies are inferred from the claim text.