Cavity soliton laser based on VCSEL with saturable absorber

We study theoretically a broad-area vertical cavity surface emitting laser (VCSEL) with a saturable absorber. We show numerically the presence of cavity solitons in the system: they exist as solitary structures formed through a modulationally unstable homogeneous lasing state that coexists with a background with zero intensity. Such a peculiar scenario endows the solitons with unique properties compared to cavity solitons in most previously studied optical systems. In particular, these solitons do not as such rely on a proper phase of the addressing pulses to be either created or deleted. We show that exciting and deleting the solitons depend crucially on whether a threshold in the soliton peak has been reached.