Overcoming Broadening Challenges and Practical Implementation of m-Plane GaN Two-Well Terahertz Quantum Cascade Laser

In this research we investigate the issues that arise from line broadening in m-plane GaN Terahertz Quantum Cascade Lasers (THz QCLs). Our study using non-equilibrium Green's functions (NEGF) shows that factors beyond longitudinal-optical (LO) phonon coupling contribute to line broadening. Despite these challenges, increased doping densities were found to increase gain, allowing for lasing at up to 280 K at 7.2 THz. This indicates the potential of practical GaN-based THz QCLs for high-temperature applications, suggesting avenues for achieving room temperature operation and advancing THz QCL development.