Multimode Dynamics

Among the possible problems that Freetwm can tackle, it can be used to study the multimode dynamics of semiconductor laser diodes out of the uniform field limit, a domain where very few theoretical results exist, although it is in this regime that most semiconductor lasers operate.
As an example, one can observe on the right some typical results of multimode dynamics obtained for a Fabry-Perot laser in which the left facet has a high reflectivity while the right facet is anti-reflection treated.
As a result of the large cavity losses, one obtains a strongly spatially asymmetric profile both for the field and the carrier density distribution (D0) within the cavity (see bottom left).
figure exampleA_3.png
In addition, the model takes into account the influence of spatial hole burning (D2) in the active material gain created by the interference pattern between the counter-propagating fields which act as a important source of gain saturation, (see bottom right).