Freetwm: a simulation tool for semiconductor lasers

J. Javaloyes and S. Balle
Departament de Fisica, Universitat de les Illes Baleares, Palma de Mallorca, Spain.
This is the homepage of Freetwm, a free software designed for the study of the dynamics of multisection semiconductor lasers based on the Traveling Wave approach of Maxwell Bloch equations.

Distributed Bragg gratings (possibly chirped), saturable absorbers and passive sections can be included. One can see on the right some typical results of passive mode-locking.
Parametric modulation of the bias current or of the reverse voltage as well as external optical injection can be achieved with arbitrary waveforms. At last, the (optional) mapping of the dynamics onto a simplified ensemble of coupled delayed equations allows for orders of magnitude speed improvements.
Movie Legend: temporal evolution of a pulsating passively mode-locked laser composed of a passive section, an amplifier, a saturable absorber and another passive section. The forward and backward waves and the population inversion are represented in red, dark and light blue, respectively. The population grating amplitude close to the mirror has been exaggerated for clarity.