LD08 – Modeling of THz Comb Emission in Difference-Frequency Quantum Cascade Lasers

The generation of terahertz (THz) frequency comb emission by intracavity difference frequency generation (DFG) in a mid-infrared (mid-IR) quantum cascade laser (QCL) is a promising alternative to direct THz QCL frequency comb generation. Concerning their room temperature operation capabilities, these devices are well suited for applications in rotational molecular spectroscopy and sensing. In order to better
understand the second-order nonlinear mixing process required for the THz frequency comb generation, we present an extensive analysis of such THz DFG-QCL comb devices using a full-wave Maxwell-Bloch equation solver. All input parameters for the Maxwell-Bloch simulations, e.g. scattering rates or dephasing rates, are calculated self-consistently using an ensemble Monte Carlo simulation toolbox.