Abstract

Energy-transfer upconversion (ETU) is a detrimental effect in many rare-earth-ion-doped infrared amplifiers and lasers [1], among them Er^{3 +}-doped waveguide amplifiers [2]. Er^{3 +} concentrations in the order of 10²⁰ cm^-3 are usually necessary to attain high gain values on the centimeter length scale of an integrated optical device. At such high Er³⁺ doping, electric dipole-dipole interactions between neighboring ions such as energy migration and ETU take place, thereby reducing the population inversion and negatively affecting the gain performance of the amplifier. We investigated these effects by lifetime and gain measurements, see Figs. 1 (a) and (c), respectively, in Al₂O₃:Er³⁺ waveguides and analyzed the results in the frame of the microscopic model developed by Zubenko et al. [3].

© 2009 IEEE