A numerical method for solving gain characteristics of Er3+/Yb3+ codoped waveguide amplifiers

By means of the interpolation and iteration methods to deal with the rate equations and the light propagation equations for the Er3+/Yb3+ codoped waveguide amplifier (EYCDWA), the gain characteristics in the forward, backward, and bidirectional pumped styles are analyzed. In order to obtain high gain, some parameters such as waveguide length, dopant concentration, pump power, and signal power are optimized. The results show that the pump power and signal power are about 50 mW and 1 mW, respectively, the gain is about 6.5 dB for the 2.0 cm-long EYCDWA with an Er3+ ion concentration of 1.5 × 1026 m–3 and Yb3+ ion concentration of 1.9 × 1027 m–3. Moreover, the upconversion is investigated for the designed device.