Improved thermoplastic-photoconductor devices for holographic recording

Thermoplastic-photoconductor devices are attractive for holographic recording because of their relatively high sensitivities, efficient holograms, and record-erase capabilities. Recent improvements in charging techniques and in the thermoplastic materials should increase the utility of these devices. Charge was applied from a transparent electrode located parallel to and at a small distance from the thermoplastic surface; charging was rapid and uniform without moving parts. Thermoplastics synthesized by polymerizing mixtures of styrene and methacrylates were capable of over 5000 record-erase cycles. Measurements of holographic recording and reconstruction parameters are presented to lend insight to the operation of these devices.