Power and modulation bandwidth of gaAs-AlGaAs high-radiance LED´s for optical communication systems

We present an analytical model for GaAs-AlGaAs double heterostructure high-radiance LED´s intended for use in optical communication systems. This model takes all the important device and material parameters, such as self absorption, heterointerfacial recombination, doping concentration, active-layer width, injection carrier density, and carrier confinement into account. A theoretical discussion of the effect of these parameters on LED output power and modulation bandwidth is given along with experimental results which are in good agreement with the model. The best high-output 50-μm LED´s (biased near saturation) emitted 15 mW into the air with a radiance of 200 W/cm². sr (highest ever reported for a surface emitter LED) and a modulation bandwidth of 17 MHz; the highest bandwidth obtained was 170 MHz at 2-mW output.