The authors present a comprehensive method to characterize the electrical, optical, and thermal performance of terahertz quantum-cascade lasers (THz QCLs). To analyze the laser waveguides and decouple the influence of different resonator parameters, the optical waveguide losses were calculated using JCMsuite's finite element method solver. The simulation of a two-dimensional waveguide cross-section was essential for determining the intrinsic waveguide loss and effective refractive index, which were used to separate the contributions of transparency current and various optical losses to the laser threshold.
V. Pistore, et al. Comprehensive assessment of terahertz quantum-cascade lasers performance characteristics. J. Appl. Phys. 136, 194506 (2024).
DOI: 10.1063/5.0234245