Oxides doped with rare-earth ions as a memory medium for rewritable optical information recording

The photoluminescent spectra of CaO and MgO oxides doped with rare-earth io ns are studied. Photoluminescence stimulated by IR light at room temperatur e is observed for the first time. Optically stimulated luminescence in Ca(M g)O:Eu,Sm for different concentrations of dopants after exposure to UV radi ation (lambda = 250 nm) and radiation with lambda = 488 nm are investigated . A physical model to explain luminescence and stimulated luminescence is p roposed. Materials based on alkaline-earth oxides activated by rare-earth i ons are suitable for multiple rewriting of information. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)01409-9].