Holographic ROM system for high-speed replication

Conventional holographic memory systems have generally focused on a page-oriented storage approach. One common characteristic of these systems is that they require the recording of thousands of separate holograms, whether as local pages or individually placed bits, in order to fill the memory to capacity. While such configurations are suitable for write-once read-many (WORM) or rewritable memories, they are not practical as a distributable read-only memory (ROM) format, which requires fast replicability for mass production. A typical page-oriented system using a megabit-sized array would require the recording of hundreds of thousands of holograms to reach capacities of 100 GB or more. Even with millisecond-order hologram exposure times, taking into account the added time required for changing positions, recording one memory to full capacity would likely require tens of minutes, if not hours. In this paper we propose a novel holographic ROM architecture in which the time required to produce a 100 GB-order capacity disc may be reduced to under a minute, and potentially to the order of seconds.