Localized states in VCSELs with Frequency Selective Feedback

We analyze a model of broad area vertical-cavity
surface-emitting lasers subjected to frequency-selective optical
feedback. In particular we analyze the spatio-temporal regimes
arising above threshold and the existence and dynamical properties
of cavity solitons. We build the bifurcation diagram of stationary
self-localized states, finding that branches of cavity solitons
emerge from the degenerate Hopf bifurcations marking the
homogeneous solutions with maximal and minimal gain. These
branches collide in a saddle-node bifurcation, defining a maximum
pump current for soliton existence which lies below the threshold
of the laser without feedback. The properties of these cavity
solitons are in good agreement with those observed in recent
experiments.