Properties of double cladding Er-Yb Co-doped fiber amplifiers

Based on rate equations, the output signal power, gain and noise characteristics of double cladding Er-Yb co-doped fiber amplifiers pumped at 980 nm were investigated numerically. Their changes as functions of the amplifier length, input pump power and input signal power were described. From a 5 m long double cladding Er-Yb co-doped fiber, for the small signal input at 1550 nm, the output signal power, gain and noise figure were obtained more than 25 dBm, more than 30 dB and less than 4 dB, respectively.