Patent ID: 7355787

Claim:
An optical amplifier assembly for submarine applications, comprising: first double stage amplifier having first and second fiber amplifiers for carrying optical signals propagating on a first optical fiber in a first direction, and second double stage amplifier having first and second fiber amplifiers for amplifying optical signals propagating on a second optical fiber in a second direction opposite said first direction, and a common pump source comprising a plurality of pump light sources, the common pump source being coupled via a coupler to said first and second fiber amplifiers of each of said first and second double stage amplifiers, said optical amplifier assembly further comprising a gain flattening filter [GFF] between the first and second fiber amplifiers of each of the first and second double stage amplifiers, wherein the common pump source is individually coupled as a co-propagating pump to the first and second fiber amplifiers of each of the first and second double stage amplifiers.