Self-consistent rate equation modelling of a Terahertz GaAs/AlGaAs quantum-cascade laser
Tóm tắt
In this work, electron transport in GaAs/AlGaAs quantum cascade lasers operating at far-infrared wavelengths is calculated self-consistently using an intersubband scattering model. Subband populations and carrier transition rates are calculated and all relevant electron-electron and electron-LO phonon scatterings between the injector/collector and active region levels (13-levels in total) are included. Employing an energy balance equation which includes the influence of both electron-LO phonon and electron-electron scattering, the method also includes the evaluation of the electron temperature of the non-equilibrium carrier distributions in the device. The calculated threshold currents (J/sub th/ = 250-300 kA/cm/sup 2/) and electric field-current density characteristics (current saturation is predicted at /spl sim/680 A/cm/sup 2/), are in good qualitative and quantitative agreement with measurements in a recent experimental realization (Kohler et al, Nature, vol. 417, pp. 156-159, 2002). Due to the increased influence on electron-electron scatterings, the electron temperature is found to be more sensitive to the current density than in mid-infrared devices. The technique promises to be a powerful tool for the optimization of new, improved Terahertz quantum cascade lasers.
Từ khóa
#Equations #Gallium arsenide #Laser modes #Quantum cascade lasers #Particle scattering #Electrons #Phonons #Laser transitions #Temperature distribution #Threshold currentTài liệu tham khảo
10.1063/1.1448393
10.1109/3.892737
10.1063/1.1423777
10.1063/1.1461054
10.1038/417156a
10.1063/1.1498861
10.1103/PhysRevLett.87.146603
harrison, 1999, Quantum Wells Wires and Dots Theoretical and Computational Physics
10.1063/1.125154
10.1063/1.1341216
10.1109/JQE.2002.1005405
10.1038/415883a
10.1063/1.1481236
10.1109/JQE.2002.1005404
10.1063/1.1367304
10.1063/1.1469657
10.1088/0034-4885/64/11/204
faist, 1994, Quantum Cascade Laser, Science, 264, 553, 10.1126/science.264.5158.553
10.1063/1.122895
10.1063/1.1474613
10.1063/1.1494457
harrison, 0, The electron temperature and mechanisms of hot carrier generation in quantum cascade lasers, Appl Phys Lett