Multiple Longitudinal Modes in Ridge MQW Laser

laserex08.in : Multiple Longitudinal Modes in Ridge MQW Laser

Requires: Blaze/Quantum/Laser
Minimum Versions: Atlas 5.28.1.R

This example demonstrates the simulation of GaAs/AlGaAs ridge laser diode with multiple longitudinal modes. Previous example showed that TE-like fundamental mode is the main lasing mode. Here we use scalar Helmholtz solver and exclude TM modes, using parameter HELM.TM. Slab transverse modes are neglected. Longitudinal modes in the range of energies [1.42; 1.5] eV are taken into account. To limit the number of longitidinal modes, we set intermode energy separation to 4meV using DELTAE parameter. If this parameter is omitted, energy separation will be that of Fabry-Perot resonator with length set by CAVITY_LENGTH. Laser simulation starts automatically whenever optical gain anywhere in the device becomes positive, which happens just before the threshold. If subthreshold behavior is of interest, use START parameter on LASER statement.

The key points of this simulation are :

  • Multi-longitudinal mode simulation, with mode competition
  • Demonstration of scalar Helmholtz solver
  • Demonstration of modal spectra.

The results show 2D plots of total optical intensity at anode bias of 1.5V. The IV log file contains information of the power, photon density modal gain, modal loss and modal refractive index for the fundamental transverse mode. Spectrum log files contain information on gain and spontaneous emission spectra for each quantum well. Modal spectrum log files are stored when SPECTRUM is specified on the SAVE statement with "_modal" appended at the end of the file name. Modal spectra contain modal gain, modal Rsp, modal photon density and modal lifetime for each longitudinal mode.

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.