Modeling and experiments of packaged Er³⁺-Yb³⁺ co-doped glass waveguide amplifiers

A full characterization of packaged Er³⁺-Yb³⁺ co-doped waveguide amplifiers (EYDWAs) fabricated using ion-exchange and field-assisted annealing was reported. The amplifier was modeled using an extended overlapping factors method, and two overlapping factors at the pump and signal wavelengths were introduced to simplify the overlapping integrals between levels' population densities and mode intensity profiles. The rate equations and the propagation equations depend on one variable: the longitudinal parameter z, and the overlapping integrals have to be carried out once only. The gain and noise characteristics of the EYDWAs were investigated, and there is good agreement between the theoretical and experimental results. With a single 975 nm diode pump of 200 mW power, this packaged ∼4.0 cm long waveguide device delivers a total net gain of ∼12.0 dB peak value at 1.534 μm, and a net gain of ∼8.0 dB and an average noise figure of ∼5.1 dB in the 1530-1560 nm band. The polarization dependent gain of <0.2 dB is also estimated for the device. Comparing to commercially available Er-doped fiber amplifiers, these low cost, high gain pigtailed glass waveguide amplifiers have a great potential to be used in optical access networks.