QCL dynamics: thermal effects and rate equations beyond mean-field approach

TL;DR

This paper enhances quantum cascade laser (QCL) modeling by incorporating thermal effects and self-heating into rate equations, improving predictions of operational thresholds and dynamics beyond traditional mean-field approaches.

Contribution

It introduces a modified rate equation model that accounts for self-heating, providing a more accurate description of QCL dynamics under thermal effects.

Findings

Temperature significantly influences QCL threshold and build-up time.

Self-heating effects can be effectively incorporated into rate equations.

The model improves understanding of QCL behavior under realistic thermal conditions.

Abstract

The correct accounting for thermal effects is always a challenge when one needs to make quantitative predictions for any laser applications. In such complicated devices as quantum cascade lasers temperature strongly affects the operational conditions preventing reaching the CW mode as well as efficient lasing in pulsed regime. Rate equations are the most effective and simple way to model laser dynamics. However, the conventional approaches operate under the mean-field approximation, considering finite number of population levels, generalizing the obtained results to the infinite number of cascades, and do not take heating into account. In this work we modify the conventional three-level rate equation approach by adding self-heating description and applying it to the calculation of QCL dynamics. As a result we show how temperature affects the threshold characteristics and build-up time and include electronic aspects to the description of QCL.