Optical amplifier, amplification fibre co-doped with erbium and ytterbium

摘要

n optical transmission system 100 intended to transmit an optical signal in a transmission wavelength band above 1570nm includes an optical amplifier 104 including an amplification fibre and a pump source for generating pump radiation. The amplification fibre includes an optical fibre co-doped with erbium and ytterbium. The concentration of erbium in the core of the amplification fibre is between 600ppm and 1000ppm. The concentration of ytterbium in the core is between 1000 and 20000 ppm.