This example shows how to model a simple Fabry-Perot laser using the INTERCONNECT Traveling Wave Laser/Gain Model Element (TWLM). The project will produce time evolution of the average carrier density and the instantaneous power at the output facets as well as the steady state laser spectrum. It uses simplified input parameters for the laser as given in reference  which are typical of a III-V heterojunction laser operating at the wavelength of 850nm.
Set up model
The system in the example file TWLMexampleLaserFP300umCF353THzR3R3nel100.icp has the following setup.
The key component in the system is the traveling wave laser (Laser TW), it could be found in the Element Library under Actives/Optical as shown below.
The key properties of the element traveling wave laser are listed below; the description of the properties can be found in the Laser TW element Library page.
The facet reflectivity at both ends of the laser can be set to less than 1, so that both ends can have lasing outputs; or one of them can be set to 1 (total reflection) so that only the other terminal can have a lasing output.
Please note that the start time of OSA_2 is set to a point after the turn-on transients have subsided in order to obtain the steady-state spectrum. The steady-state time can be measured from the output trace of OOSC1. Based on the output of OOSC1, the "start time" of OSA_2 is set to be 5 ns as shown in the following property view .
The following figures are the simulation results of the Fabry-Perot laser:
output trace from OOSC1 (absolute value squared of field in units of square root of Watts),
output trace from OSC1,
output from OSA2,
and results view of laser model: measured spectrum (for diagnostic purposes).
- A.J Lowery, “New dynamic semiconductor laser model based on the transmission-line modelling method”, IEE PROCEEDINGS, Vol. 134, Pt. J, No. 5, OCTOBER 1987