DESIGN OF 1480-NM DIODE-PUMPED ER-3-DOPED INTEGRATED OPTICAL AMPLIFIERS()

Erbium-doped Y2O3 integrated optical amplifiers are designed for low-t hreshold operation and 3 dB amplification. The most important design p arameter for minimal threshold, the erbium concentration, is found to have an optimum value of 0.35 at% for a given waveguide structure with 1.0 dB cm-1 background loss. The corresponding threshold power is 7 m W. The pump power to obtain 3 dB gain is found to be 22 mW for an ampl ifier with an optimum erbium concentration of 0.6 at% and 2.8 cm lengt h. At 30 mW pump power the maximum gain is shown to be 5 dB. Designing is done using a comprehensive numerical model of an erbium-doped inte grated optical amplifier. In the model two-dimensional intensity-depen dent overlap integrals are used, which allow arbitrary erbium dopant p rofiles and waveguide cross-sections. Concentration-dependent effects such as quenching and upconversion are also included in the model. Inp ut parameters for the model are determined from measurements on an uno ptimized Er : Y2O3 optical waveguide amplifier. Amplification simulati ons and gain measurements of the unoptimized waveguides are found to b e in close agreement, providing a sound basis for the design calculati ons.