Using electron trapping materials for optical memory

Photostimulated luminescence (PSL) in Eu(Ce) and Sm co-doped sulphides (SrS and CaS) and oxides (Y2O3) has been studied in order to develop a novel erasable and rewritable optical memory using the photoluminescence method. When 250 nm W irradiated samples were excited by a Nd-laser (1064 nm), PSL was observed at 600-650 nm for Eu doped materials and at 560-600 nm for Ce3+-doped materials, due to the 5d-4f transition of Eu2+ and Ce3+. The process of writing, storing, and erasing information was demonstrated experimentally in sulphides Sr(Ca)S and oxides (Y2O3) doped two rare-earth ions Eu2-(Ce3+) and Sm3+. Photoluminescence stimulated by IR-light in rare-earth oxides doped with rare-earth ions has been observed for the first time. (C) 2001 Elsevier Science B.V. All rights reserved.