Measurement of gain and saturation parameters of a single-mode Yb:silica fiber amplifier

• A low power fiber master oscillator power amplifier is designed and fabricated.
• Competition between ASE noises and input signal to the amplifier investigated.
• We calculated the gain and saturation parameters of the fiber amplifier.
• Change in pump power, doped fiber’s length and concentration affect the amplifier gain and saturation power.
• Parasitic noises and their evolutions due to power change are discussed.

A master oscillator-power amplifier (MOPA) has been fabricated and optimized for measuring the small-signal gain (γ0) and saturation power (Psat) of a continuous-wave (CW) single-mode (SM) double-clad (DC) Yb-doped (YD) silica fiber amplifier at 1082.5 nm. It was shown that the gain and saturation properties are strongly dependent on the pump power, dopant concentration and fiber length mainly due to the dominant effect of the overlapping factor.