High-density frequency domain storage in alkaline earth sulfides double doped with lanthanide
Mohamed F. Aly, Levent Biyikli, Sameh I. Dardona +1 more
Previously we have reported the largest number of photon- gated spectral holes ever burned in a solid. This has interest in their applications in optical storage. However, multiple holeburning in MgS:Eu resulted in noticeable erasure of the previously burned holes. This was attributed to the mechanism of holeburning in this material where both Eu2+ and Eu3+ are stable ions. In gated holeburning, Eu2+ ions are ionized. Eu3+ that form deep traps, capture the electrons generated during the holeburning and are converted to Eu2+. The Zero Phonon Line (ZPL) of these newly formed Eu2+ ions are randomly distributed across the inhomogeneous line causing a partial erasure of the holes burned earlier. This reduces the efficiency of holeburning. Co-doping of MgS:Eu and CaS:Eu with different rare earth (RE) ions has been investigated to provide deep electron traps other than Eu3+. Furthermore, co-doping provides the opportunity to burn holes in multiple ZPLs belonging to different REs, thus increasing the storage density many folds.
Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 29, 2000•0 citations