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Title: Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

Terahertz-frequency quantum cascade lasers (THz QCLs) based on bound-to-continuum active regions are difficult to model owing to their large number of quantum states. We present a computationally efficient reduced rate equation (RE) model that reproduces the experimentally observed variation of THz power with respect to drive current and heat-sink temperature. We also present dynamic (time-domain) simulations under a range of drive currents and predict an increase in modulation bandwidth as the current approaches the peak of the light–current curve, as observed experimentally in mid-infrared QCLs. We account for temperature and bias dependence of the carrier lifetimes, gain, and injection efficiency, calculated from a full rate equation model. The temperature dependence of the simulated threshold current, emitted power, and cut-off current are thus all reproduced accurately with only one fitting parameter, the interface roughness, in the full REs. We propose that the model could therefore be used for rapid dynamical simulation of QCL designs.
Authors:
; ; ;  [1] ; ; ; ; ; ; ; ; ; ;  [2] ;  [3] ;  [4]
  1. School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland 4072 (Australia)
  2. School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)
  3. School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072 (Australia)
  4. Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom)
Publication Date:
OSTI Identifier:
22398918
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CARRIER LIFETIME; DIAGRAMS; EFFICIENCY; GAIN; HEAT SINKS; INTERFACES; LASERS; MODULATION; QUANTUM STATES; REACTION KINETICS; ROUGHNESS; STEADY-STATE CONDITIONS; TEMPERATURE DEPENDENCE; THRESHOLD CURRENT; THZ RANGE; VISIBLE RADIATION