One of the more exotic projects spawned by the Microelectronics & Computer Technology Corp pre-competitive research co-operative is making progress towards its goal of creating a memory system that uses diffracted light as the storage medium. Austin, Texas-based Tamarack Storage Devices Inc reports that it has completed assembly and initial testing of a fully integrated optical head for its MultiStore Holographic Storage System, and says it has demonstrated the operational viability of the mechanical and electronic subsystems, including the servo operation of motors and beam steering devices. The optical head is the core of the optical storage system, integrating each of the critical components that must function smoothly to store and recover data. The company says it has now demonstrated the basic operation of the optical head by writing and retrieving multiple images through the holographic process. It has demonstrates a process it calls angle multiplexing, based on a custom-designed miniature galvanometer (remember the primitive instrument where the needle moved in the presence of an electric current), less than 12mm on each side. The angle multiplexing technique uses tiny mirrors to direct the laser beams to precise pages in any given location on the storage medium. It says it has also demonstrated data image formation through a spatial light modulator, and data retrieval through a charge-coupled device, both specially designed and fully integrated into the optical head. Tamarack is now working on engineering initial commercial units from the alpha design. In its production version, MultiStore will be a 20Gb device, based on a jukebox architecture, but there will also be PCMCIA versions for portable computers, and high capacity-high performance systems. The firm is largely funded by Projectavision Inc, New York, with 37%, and the Austin co-op, which has 30%, and the two have invested over $10m in Tamarack’s technology. Projectavision wants to use the high-density, high speed holographic store in consumer and entertainment products, notably a solid-state, portable, front and rear projection television system.
