A microscopic monomeric mechanism for interpreting intrinsic optical bistability observed in Yb3+ - doped bromide materials.

We present a microscopic, monomeric mechanism explaining some essential aspects of intrinsic optical bistability (IOB) phenomena observed in Yb3+-doped bromide materials. Our mechanism is based on the coupling between the electronic degrees of freedom of the Yb3+ ion and the A1g vibrational local mode of the [YbBr6]3- coordination unit. The IOB exhibited by CsCdBr3:Yb3+ is reproduced.