Finite element characterisation of terahertz quantum cascade laser waveguides

Compact Quantum Cascade Laser waveguides have been analyzed using the full-vectorial finite element method. Modal intensity profiles, detailed power confinements and loss factors have been characterized for waveguides based on GaSb/AlGaSb multiple quantum well structures. Variations in these key parameters were also further investigated whilst varying the semiconductor doping concentration. Higher order modes having a low propagation loss were also shown.