Lasers with saturable absorber driven by a coherent field

We derive the semiclassical equations governing the response of a solid-state monochromatic laser with saturable absorber driven by an external coherent field. The behavior of the emitted field intensity versus either the driving field intensity or the pump parameter of the amplifying atoms displays the same qualitative behavior. Three possible situations can appear, depending on the values taken by the relevant parameters: for a given external field intensity or pump parameter there can be one, two or three stable values of the emitted field intensity. In this way we have an example of a system which displays mono-, bi- or tristability.Chercheur Qualifié F.N.R.S.