Effect of pump power on gain and saturation of double-clad fiber amplifiers

Designing and fabrication of a continuous wave double-clad oscillator-amplifier array was carried out in order to measure the small-signal gain and saturation power. In the array, the low power fiber laser seed signal at 1082.5nm is amplified through the single-mode double-clad ytterbium-doped silica fiber amplifier. The gain and saturation parameters can be determined using the steady-state amplification relation. It is shown that those parameters increase at stronger pump powers of the amplifier mainly due to the dominant effect of the overlapping factor.