Self-consistent solutions to the intersubband rate equations in quantum cascade lasers: Analysis of a GaAs/AlxGa1−xAs device

Abstract

This is a repository copy of Self-consistent The carrier transition rates and subband populations for a GaAs/AlGaAs quantum cascade laser operating in the mid-infrared frequency range are calculated by solving the rate equations describing the electron densities in each subband self-consistently. These calculations are repeated for a range of temperatures from 20 to 300 K. The lifetime of the upper laser level found by this self-consistent method is then used to calculate the gain for this range of temperatures. At a temperature of 77 K, the gain of the laser is found to be 34 cm Ϫ1 /͑kA/cm Ϫ2 ͒, when only electron-longitudinal-optical phonon transitions are considered in the calculation. The calculated gain decreases to 19.6 cm Ϫ1 /͑kA/cm Ϫ2 ͒ when electron-electron transition rates are included, thus showing their importance in physical models of these devices. Further analysis shows that thermionic emission could be occurring in real devices.

Self-consistent energy balance simulations of hole dynamics in SiGe∕SiTHz quantum cascade structures

“…One approach relies on self-consistent solutions of rate equations. [8][9][10][11][12][13] Another approach uses the microscopic, and computationally more demanding Monte Carlo technique. [14][15][16] Although the latter does not make the assumption of equilibriumlike carrier distributions over states within any single subband, and therefore gives a deeper insight into the electron dynamics, the former are much faster while still giving quite good estimates of device characteristics.…”

Monte Carlo modeling applied to studies of quantum cascade lasers

“…The rate equation method (Donovan et al 2001;Indjin et al 2002aIndjin et al , b, 2003Indjin et al , 2004Chen et al 2011;Saha and Kumar 2016), often applied to the description of the properties of QCL structures is based on the semiclassical electron transport model (transport dominated by scattering) described by Boltzmann equation, which in fact, is the same physical model as in the MC method. The important point is that the algorithm is easier to implement and less demanding of computational time, at the price of an additional hypothesis about the shape of the electron distribution function, which is usually taken as a Fermi-Dirac distribution, or in even simpler models by using phenomenological values of electron scattering times between subbands.…”

Metal-free quantum-based metamaterial for surface plasmon polariton guiding with amplification

“…The accuracy of this statement depends on k-dependence of effective mass model Amplification via intersubband transitions may be achived by different schemes, as it was shown both theoretically and experementaly [26 -33]. The most promissing technique is Quantum Cascade (QC) [26][27][28][29][30].…”