Effects of pumped styles on power conversion efficiency and gain characteristics of phosphate glass Er3+–Yb3+-co-doped waveguide amplifiers

In order to analyze the power conversion efficiency (PCE) and the gain characteristics of the phosphate glass Er3+–Yb3+-co-doped waveguide amplifier (EYCDWA), formulas are derived from the rate equations and the light propagation equations under the uniform dopant and the steady-state conditions. In the derivation of these formulas, we have neglected the amplified spontaneous emission (ASE) and have introduced the initial energy transfer efficiency. By using these formulas, the effects of the pump power, signal power and waveguide length on the PCE and the gain characteristics of the EYCDWA are analyzed, and some useful results are obtained in three kinds of pumped styles, i.e. the forward-, backward- and bidirectional pumped styles.