The gain and noise characteristics of double cladding ytterbium-doped fiber amplifiers at different pump modes

In order to investigate the gain and noise characteristics of double cladding ytterbium-doped fiber amplifiers at different pump modes,numerical analysis of 910nm ytterbium-doped fiber amplifiers is performed.The results show that pump mode has less effect on gain than noise figure,and the fiber amplifier has low noise under forward and bi-direction pumping schemes at optimal fiber length.The results are useful for experimental design.