Practical angular-multiplexing holographic data storage system with 2 terabyte capacity and 1 gigabit transfer rate

Aiming at the realization of an optical data storage system with a large disc capacity and a high transfer rate suitable for digital data archiving, we have defined the specifications of an angular-multiplexing holographic data storage system with a disc capacity of 2 TB and a transfer rate of 1 Gbps on the basis of a run-length-limited (RLL) high-density recording method using RLL modulation. To realize the specifications, RLL turbo coding, a servo system for the reference beam angle, and a servo system for book tracking were newly invented. Also, to satisfy the specifications, a holographic disc and several key components were developed in cooperation with several specialty companies. Eventually, we confirmed a high-density recording of 2.4 Tbit/in.2 achieved by the RLL high-density recording method, using evaluation equipment complying with the specifications for single book recording.