Circuit model of quantum cascade lasers for simulation of influence of doping density

In this paper, a new equivalent circuit-level model of QCLs is introduced to overcome drawbacks of the previous models. The photon gain coefficient and injection current efficiency both depend on the injector doping density in the model. A revised three-level rate equations that permit a compact and computationally efficient implementation. The electron scattering time, relaxation time and escape time between the corresponding levels are obtained by employing a fully non-equilibrium self-consistent Schrödinger-Poisson analysis of the scattering rate and energy balance equations. A general diode sub-circuit is adopted to model the current-voltage relationship. This new circuit-level model can be readily incorporated into a standard circuit simulation environment such as SPICE, which enables electronic integrated circuit designers to simultaneously evaluate the performance of both QCL and electronic devices.