In order to simplify the threshold determination, reduce the inter-pixel cross-talk, and improve the storage density for high-density volume holographic data storage, a two-dimensional constant-weight sparse modulation code is proposed. The evaluation criteria and design rules are investigated based on the page-oriented optical data storage system. Coding parameters are optimized to achieve large channel capacities. An 8:16 modulation code is designed to reduce the raw bit error rate and its performances are experimentally evaluated. A raw bit error rate of the magnitude of 10^?4 is obtained with a single-data-page storage and 10^?3 with multiplexing.

关键词： Volume holographic data storage,  Modulation codes,  Sparse codes,  Raw bit error rate,  Channel capacity