Three types of electronic optical bistabilities in CdS

We investigate optical bistability in CdS, induced by photo-electronic non-linearities. Varying the photon energy and the temperature of the sample we find three different types of optical bistability. The switching times are always around 1 ns or below, notably 300 PS for dispersive optical bistability. Optical bistability by bleaching of absorption at room temperature shows a contrast ratio of about 50 between the two stable branches. The dependence on various parameters, including the microscopic foundations, is discussed experimentally as well as theoretically. is defined by the existence of two possible stable outputs for a certain