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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
holographic data storage a technique used to store multiple images, or 2-D arrays of digital information, as multiplexed holograms in an optically sensitive material. Multiplexing techniques include angle, frequency, and spatial position. Angle and frequency multiplexing techniques are based on Bragg selectivity where angle multiplexing favors transmission geometries and frequency multiplexing favors reflection geometries. holographic interconnect free-space interconnect that uses holograms to control optical paths from sources to detectors. The hologram provides the interconnection by forming the intentionally distorted image of the source array on the detector array. A hologram can be viewed as a combination of gratings. Each grating directs a light beam passing through it to a new direction. The hologram can be displayed by a spatial light modulator to achieve dynamic reconfiguration. holography holograms. the science of making and reading
Image Processing System Based on PST
Published in Stepan Bilan, Sergey Yuzhakov, Image Processing and Pattern Recognition, 2018
Saving of pattern surfaces in analog form can, with high precision, display the functions of the area of intersection. A variant of this saving may be the use of holography. The holographic data storage methods are at research stage.
Rate-4/5 4-ary modulation code for 4-level holographic data storage systems
Published in Cogent Engineering, 2023
The massive growth of updated-regularly data has challenged traditional storage systems. To deal with ever-increasing demands, novel technologies are needed to expand the storage capacity. Several new technologies for magnetic recording have been examined, including bit-patterned media recording and energy-assisted magnetic recording (Shiroishi et al., 2009). Emerging non-volatile memories (Khan & Ghosh, 2020), such as three-dimensional NAND flash, resistive random-access memory (ReRAM), and spin-transfer torque magnetic random-access memory (STT-MRAM), are expected to replace existing technologies, such as established random-access memory (RAM), like dynamic or static RAM, to lead the electronic memory industry. As for optical storage devices, holographic data storage (HDS) systems have become the most esteemed candidates for ultra-high-density optical storage systems because of the strengths of fast access time, extensive storage capability, greener storage, and potential uses. The HDS optical working principle can be briefly described as follows. The HDS system stores data throughout the volume of the medium rather than its surface. The data sources are first formatted into m-ary symbols (e.g., binary bits in the case of the binary HDS), and the symbols are then converted into multi-level square pixels. A page composing device, using a laser, is used to impress the pixels onto a signal beam. The signal beam is interfered with a reference beam for recording an interference grating (page) inside tiny holograms. Adjusting the laser angle (angular multiplexing technique) allows various pages to be recorded in one volume. The recorded data can be retrieved by combining an incident reference beam on the medium and a high-performance detector.