Bifurcation study of regular pulse packages in laser diodes subject to optical feedback

We study the influence of delayed optical feedback from a short external cavity on the emission dynamics of semiconductor lasers using the Lang and Kobayashi rate equation model. A combination of numerical integration and continuation techniques allows us to bring new light into the bifurcation scenario leading to the regular pulse packages (RPP) regime. We give examples of bistability between RPP and time-periodic or steady state solutions. Our bifurcation study of RPP regime is complemented by an analysis of the dependency of the RPP period on the laser and feedback parameters. We qualitatively study this new dynamical regime by plotting a two-dimensional map in the feedback parameters space. The occurrence of RPP is furthermore associated with a topological change in the bifurcation diagram and accompanied by the creation of a new type of bifurcation bridge between a mode and an antimode.