Enhanced gain and noise figure performance of high concentration Er3+-Yb3+-codoped phosphate fiber amplifiers

A full characterization of Er3+-Yb3+ co-doped fiber amplifiers (EYDFA) is done by numerically solving the simultaneous calculation of the rate and propagation equations considering the forward- and backward-amplified spontaneous emissions (ASE ± ) propagation. The effect of erbium and ytterbium codoping concentrations on the gain of the amplifier is evaluated. With optimal calculated parameters, a gain of 32.7 dB and a fiber length of 3.54 cm with pump and signal powers of 200 mWand 1 μW in optimal codoping concentrations is obtained. Simulations have been done for gain characteristic and noise figure of an erbium-doped fiber amplifier (EDFA) with parameters similar to EYDFA to compare the obtained results. The proposed model and simulation results are validated with published experimental results.