Quantum cascade lasers

nextnano.NEGF

• Nonequilibrium Green's function (NEGF) method for calculating I-V curves and gain
  
• NEGF quantum transport based on the code written by Thomas Grange
• Documentation

• Download nextnano.NEGF including an evaluation license for a few months.

 

This video (mpg4, 23 MB) shows how a QCL works. The first 10 seconds summarize the features of our software, the remaining 20 seconds show the animated simulation results. At 20 seconds, the QCL starts to lase: The electron density (figure on the right) shows the population inversion, i.e. the higher state has a larger electron population than the lower lasing state.

Information on nextnano software for QCLs

(low resolution pdf)
(high resolution pdf)

A good introduction into the nextnano.NEGF software is the tutorial talk Modeling electron transport in quantum cascade lasers given by Thomas Grange at the International Quantum Cascade Laser School and Workshop (Cassis/France, 2018).

• nextnano.NEGF (NEGF)
  THz GaAs/AlGaAs (Fathololoumi)
• QCL
  Simple quantum cascade structure
• QCL
  Quantum cascade laser
• RTD
  This tutorial demonstrates the NEGF method with a Resonant Tunneling Diode (RTD) as an example.

If you are interested in further tutorials, please contact stefan.birner [at] nextnano.com.

Intersubband transitions in InGaAs/AlInAs multiple quantum well systems

What you can learn:

• single-band effective mass vs. 8-band k·p, InGaAs/AlInAs
• self-consistent Schrödinger-Poisson equation, 8-band k·p Schrödinger equation

This figure shows the calculated electron density in a THz QCL.

This figure shows the calculated gain of a THz QCL.

nextnano software for quantum transport

1) nextnano.NEGF

• Nonequilibrium Green's function (NEGF) method for calculating I-V curves and gain
  
• NEGF quantum transport based on the code written by Thomas Grange
• Documentation

• Download nextnano.NEGF including an evaluation license.

  

nextnano.MSB

• Nonequilibrium Green's function (NEGF) method for calculating I-V curves and gain based on the multi-scattering Büttiker probe model (MSB)
• NEGF quantum transport based on the MSB method (code written by Peter Greck)
• nextnano.MSB

• Download nextnano.MSB including an evaluation license until 2016-12-31.

  

 

2) nextnano³ & nextnano++

• self-consistent Schrödinger and Poisson equations
• 8x8 k.p Schrödinger equation
• strain
• Documentation (nextnano³)
• Documentation (nextnano++)

The following two papers give a very basic introduction to QCL modeling.

• Simulation of quantum cascade lasers - optimizing laser performance
  S. Birner, T. Kubis, P. Vogl
  Photonik international 2, 60 (2008)
• Simulation zur Optimierung von Quantenkaskadenlasern
  S. Birner, T. Kubis, P. Vogl
  Photonik 1/2008, 44 (2008)

Our recent publications on QCL modeling:

• Room temperature operation of n-type Ge/SiGe terahertz quantum cascade lasers predicted by non-equilibrium Green's functions
  T. Grange, D. Stark, G. Scalari, J. Faist, L. Persichetti, L. Di Gaspare, M. De Seta, M. Ortolani, D. J. Paul, G. Capellini, S. Birner, M. Virgilio
  Applied Physics Letters 114, 111102 (2019)
  arXiv: https://arxiv.org/abs/1811.12879
• Optimization of terahertz quantum cascade lasers by suppressing carrier leakage channel via high-energy state
  T.-T. Lin, L. Wang, K. Wang, T. Grange, H. Hirayama
  Applied Physics Express 11, 112702 (2018)
• Broadening mechanisms and self-consistent gain calculations for GaN quantum cascade laser structures
  K. Wang, T. Grange, T.-T. Lin, L. Wang, Z. Jéhn, S. Birner, J. Yun, W. Terashima, H. Hirayama
  Applied Physics Letter 113, 061109 (2018)

• Non-equilibrium quantum transport theory for quantum cascade lasers
  T. Kubis, C. Yeh, S. Birner, P. Vogl
  Poster at the CLEO/Europe-IQEC 2007 conference