Monte Carlo simulation of extraction barrier width effects on terahertz quantum cascade lasers

Abstract

The effect of extraction barrier width on the performance of a resonant-phonon terahertz quantum cascade laser is studied using the ensemble Monte Carlo method. The width of extraction barrier is varied from 48to33A with a stepsize of −3A. The calculated threshold current density increases monotonously from 436to1054A∕cm2 with decreasing extraction barrier width, while the peak gain shows nontrivial behavior. These findings agree well with an experimental study. The simulation results suggest an optimal extraction barrier width of 36A for peak gain and for the best temperature performance.