Doping in quantum cascade lasers. I. InAlAs-InGaAs/InP midinfrared devices

The effect of the doping densities on the performance of 9 mu m InAlAs-InGaAs/InP quantum cascade lasers is presented. Doping densities varying between 1.0x10(11) and 2.6x10(11) cm(-2) were investigated. In this range, a linear increase in both threshold and maximum current density with sheet carrier density is observed. These effects are explained using a model based on resonant tunneling transport and rate equations. (c) 2006 American Institute of Physics.