This short course addresses the fundamental principles and design issues pertaining to digital holographic data storage (HDS). The fundamental principles of holography, including formation of and diffraction from thick diffraction gratings, are explained. Multiplexing techniques for thick gratings based on Bragg, momentum, or correlation techniques are discussed and explained with an introduction to k-space analysis.
The system architecture of phase conjugate polytopic-angle based systems is presented and their key design issues explained. The monocular architecture version of angle-polytopic is also explained. The metrics used to determine basic system performance and limitations are discussed. Write strategies and record scheduling for achieving high capacity in HDS systems are described. The concepts and issues with mastering and replication of holographic media are also explained. For angle multiplexing based systems, the servo systems and tolerances are discussed. These include thermal compensation and disk position and tilts. Key system component (laser, SLM (Spatial Light Modulator), optical design, and detector) requirements for high performance HDS systems are discussed.
The data channel for HDS systems is particularly different than conventional optical storage systems. The key issues such as over-sampled detection, interleaving, and error correction are presented.
HDS media requirements are explained and related to drive performance. Techniques for testing basic media parameters are also presented.