Advanced Lens Design for Bit-Wise Volumetric Optical Data Storage

The storage capacity of a fluorescent bit-wise volumetric optical data storage system is limited by the inter-layer crosstalk and the maximum compensation range of spherical aberration induced by different layers inside the medium. Lens designs of far-field and near-field optical systems suitable for volumetric storage are presented. The maximum compensation range of each design is calculated. The storage densities of far-field and near-field confocal systems in terms of bits-in -2 are derived based on the maximum compensation ranges and appropriate data layer spacings that induce a -30 dB maximum level of inter-layer crosstalk. It is shown that an optimized near-field system is able to achieve 1.65 Tb-in -2 data density.