Simulation of optically pumped mid-infrared intersubband semiconductor laser structures

A theoretical self-consistent investigation of optically pumped mid-infrared intersubband semiconductor laser with hot electron effects is presented. Electron dynamics under optical pumping are investigated within a rate equation formulation where particle and energy flow equations are derived from Boltzmann's equation using Fermi statistics. Electron-polar optical phonon interactions with suitable screening are calculated by using a macroscopic model with slab and interface phonon modes. Our calculations show that despite hot electron effects, population inversion between the first and second excited states can occur at low temperatures under intersubband optical excitation. It is anticipated that lasing in the mid-infrared can be achieved with asymmetric quantum well structures optimized for electron concentrations exceeding 10¹¹/cm².