Erasable optical memory using stimulated electronic transition concept

Mass storage optical memory for use aboard unmanned orbital space platforms are currently under development by NASA. These storage systems with large information capacities, high data transfer rates, and high mean time between failures are needed. An optical system using stimulated electronic transition (SET) concept would be ideal for this application. For a single reading and writing beam system, the estimated storage capacity of 66 Gbits per disk, and a data transfer rate of 186 Mbits per second can be achieved. There are several oxide and sulfide materials that can be doped with rare earth elements to produce SET for optical storage. Unlike magneto-optic and phase change processes, the SET concept does not involve localized heating which produces material fatigue. Since electronic transitions are the only processes involved in SET storage, the disk will have an infinite lifetime.