Multiwavelength, multilevel optical storage using dielectric mirrors

Interlayer cross talk in dual-layer read-only optical disks

“…The interference of the laser beam propagating between the data layers is taken into consideration in the model so that the optical energy accumulated on the out-of-focus data layer that results in interlayer cross talk is derived. 17 The interlayer cross talk, denoted N͑t͒, is derived by taking the convolution 13,17 of the enlarged spot profile and the reflectivity distribution of the out-offocus data surface: (2) where h͑x, y͒ denotes the optical energy accumulated on the out-of-focus layer. The spatial function f ͑x, y͒, which comprises a numerically simulated, semiinfinite matrix of phase marks in random order, defines the reflectivity distribution of the out-of-focus data surface.…”

“…Volumetric optical storage multiplies the recording density by incorporating plural data layers as recording media, with the data recorded on each layer of the multilayer structure. [1][2][3] The concept and the attractive attributes of volumetric optical storage were widely accepted with the commercialization of DVD 4 ͑digital versatile disk͒. Significant efforts were made to develop volumetric optical disks through suitable modification of the reflectance of thin-film layers, such as magneto-optical, phase-change, or dye-based media.…”

High-density Er-implanted GaN optical memory devices

“…First proposed in 1960, volumetric optical data storage has proven extremely difficult to achieve. 8 -11 Currently, holographic data-storage, [12][13][14] multilayer disk technology, 15,16 and 3-D bit-oriented methods that use femtosecond lasers are the leading volumetric technologies. 17 All three approaches promise to provide storage density that is hundreds of times denser and access speeds that are faster than current optical disk media.…”