CdF2 crystals with bistable impurity centers as media of the real-time holography

Bistable (DX) impurity centers in semi-conductors provide opportunity for writing reversible phase hologram due to photo-induced change of the center state. The non-traditional ionic CdF2 semi-conductor doped with some column-III elements (Ga, In) that form DX centers is promising materials for the real-time holography over a wide time range from seconds to ∼100 ns or less with the temperature used as the controlling parameter. Processes of photo- and thermal-induced conversion of bistable center states as mechanisms of writing and decay of holographic gratings are discussed. Holographic parameters of CdF2:Ga and CdF2:In based media are considered as well as their possible use in optical devices.