A Versatile Physics-Based Circuit Model for Mid-Infrared Quantum Cascade Lasers

In this paper, we present a comprehensive circuit-level model that accounts for the thermal and bias dependence of a quantum cascade (QC) laser's behavior. The equivalent circuit model of laser by employing a number of quantum mechanical models such as the coherent transport, simplified four-level carrier scattering rates, and heat transfer equation is developed. The total equivalent circuit is composed of input circuit coupled to intrinsic QC circuit and thermal circuit which models the behaviors of each component and whole device. In the model, to take into account the field dependence of the circuit parameters including the detuning and energy levels, backfilling excitation energy, and escape activation energy, the extraction of parameters has been performed as fitted functions by a self-consistent solution of Schrodinger–Poisson equations for a wide range of applied electric fields. The presented model is used to investigate the static and dynamic performances of QC laser operating in the mid-infrared (Mid-IR). For a typical Mid-IR QC laser, a good agreement was found for the temperature-dependent light output–current characteristics.