A multiple page fully digital holographic data storage system is demonstrated. This system is used to store and retrieve digital image and compressed video data with a photorefractive crystal. Architecture issues related to spatio-rotational multiplexing and novel error-correcting encoding techniques used to achieve low bit-error rates are discussed.

https://science.sciencemag.org/content/sci/265/5173/749.full.pdf

Volume Holographic Storage and Retrieval of Digital Data

An encrypted optical memory system using double random phase codes in the Fresnel domain is proposed. In this system, two random phase codes and their positions form three-dimensional keys for encryption of images and are used as keys to recover the original data. The third dimension is the positions of the codes, which can have as many as three degrees of freedom. Original images encrypted by use of the two phase codes located in the Fresnel domain are stored holographically in a photorefractive material. We demonstrate in preliminary experiments encryption and decryption of optical memory in a LiNbO3:Fe photorefractive crystal by use of angular multiplexing.

Encrypted optical memory system using three-dimensional keys in the Fresnel domain.

Combinations, called matrices with memories, of matrix materials that are encoded with an optically readable code are provided. The matrix materials are those that are used in as supports in solid phase chemical and biochemical syntheses, immunoassays and hybridization reactions. The matrix materials may additionally include fluophors or other luminescent moieties to produce luminescing matrices with memories. The memories include electronic and optical storage media and also include optical memories, such as bar codes and other machine-readable codes. By virtue of this combination, molecules and biological particles, such as phage and viral particles and cells, that are in proximity or in physical contact with the matrix combination can be labeled by programming the memory with identifying information and can be identified by retrieving the stored information. Combinations of matrix materials, memories, and linked molecules and biological materials are also provided. The combinations have a multiplicity of applications, including combinatorial chemistry, isolation and purification of target macromolecules, capture and detection of macromolecules for analytical purposes, selective removal of contaminants, enzymatic catalysis, cell sorting, drug delivery, chemical modification and other uses. Methods for tagging molecules, biological particles and matrix support materials, immunoassays, receptor binding assays, scintillation proximity assays, non-radioactive proximity assays, and other methods are also provided.

Matrices with memories and uses thereof

Combinations, called matrices with memories, of matrix materials with remotely addressable or remotely programmable recording devices that contain at least one data storage unit are provided. The matrix materials are those that are used in as supports in solid phase chemical and biochemical syntheses, immunoassays and hybridization reactions. The data storage units are preferably non-volatile antifuse memories. By virtue of this combination, molecules and biological particles, such as phage and viral particles and cells, that are in proximity or in physical contact with the matrix combination can be labeled by programming the memory with identifying information and can be identified by retrieving the stored information. Combinations of matrix materials, memories, and linked molecules and biological materials are also provided. The combinations have a multiplicity of applications, including combinatorial chemistry, isolation and purification of target macromolecules, capture and detection of macromolecules for analytical purposes, selective removal of contaminants, enzymatic catalysis, chemical modification and other uses.

Remotely programmable matrices with memories

In this paper, we discuss fundamental issues underlying holographic data storage: grating formation, recording and readout of thick and thin holograms, multiplexing techniques, signal-to-noise ratio considerations, and readout techniques suitable for conventional, phase conjugate, and associative search data retrieval. Next, we consider holographic materials characteristics for digital data storage, followed by a discussion on photorefractive media, fixing techniques, and noise in photovoltaic and other media with a local response. Subsequently, we discuss photopolymer materials, followed by a discussion on system tradeoffs and a section on signal processing and en/decoding techniques, succeeded by a discussion on electronic implementations for control, signal encoding, and recovery. We proceed further by presenting significant demonstrations of digital holographic systems. We close by discussing the outlook for future holographic data storage systems and potential applications for which holographic data storage systems would be particularly suited.

/pdf/holographic-data-storage-systems-3glg5sf5v9.pdf

Holographic Data Storage Systems

As many as 5000 holograms of high-resolution images (320 × 220 pixels) have been stored within a single crystal of Fe:LiNbO3. The nominal angle between the reference beam and the object beam was 90°. Fractal-space multiplexing was used to increase the storage bandwidth.

Fai H. Mok

Papers

Angle-multiplexed storage of 5000 holograms in lithium niobate.