In this paper the structure and operation principle of Erbium-Doped Fiber Amplifier(EDFA) are introduced firstly.Then
the factors influencing the gain and Noise Figure(NF) of EDFA are investigated comprehensively and deeply with laser principle and energy-level theory.Some important conclusions about the relation of gain
noise and pump power
pump way
input signal power
erbium-doped fiber length
etc are drawn and verified further through the experiment;The methods to enhance gain and reduce NF are proposed.Finally
according to those conclusions
a c-band
high gain and low noise optical circuit of EDFA is designed
and the optical circuit has already been applied to project practice.