Instabilities of lasers with moderately delayed optical feedback

We Perform a bifurcation analysis of the Lang-Kobayashi system for a laser with delayed optical feedback in the situation of moderate delay times. Using scaling methods, we are able to calculate the primary bifurcations, leading to instability of the stationary lasing state. We classify different types of pulsations and identify a codimension two bifurcation of fold-Hopf interaction type as the organizing centre for the appearance of more complicated dynamics