Optical data storage holographic

Photopolymers and photothermoplasts are mentioned only in connection with holographic data storage (see Holography). The classical method of optical data storage in silver haUde films (photographic film, microfiche technique) is not discussed (see Photography). 

Other dye-based technologies evaluated for optical data storage include photo-chromic dyes for rewritable systems and azo dyes for holographic data storage. Spirobenzothiopyran dyes such as (40) absorb in the red/near-IR in their colored form and are suitable for erasible optical data storage [34]. Dyes for holographic data storage, such as (41), are similar to those used in nonlinear optics [35] (see below). 

Holographic Optical Data Storage and Other Applications... 

The combination of these features presents photochromic IsoSm films as interesting and diverse media for optical data storage. In Section 5.4, we consider holographic grating recording in copolymer films and related (combined) photorecording techniques. 

B. H. Cumpston, J. W. Perry, and S. R. Marder, Method and Apparatus for Optical Data Storage Using Nonlinear Heating by Excited State Absorption for the Alteration of Preformatted Holographic Gratings, 2001, US 6322931. 

Photochromic polymers have played a pivotal role in the development of novel materials for optical data storage. Advances in holography have benefited from early research into PAPs. Although not based on PAPs, the first commercial holographic data storage devices are now available. 

We have prepared multi-component photorefractive polymers for optical data storage applications (8). This photorefractivity is a combination of two functionalities electro-optic effect and photoconductivity. We have achieved holographic diffraction efficiencies up to >30% in our composites. 

Fourier transformation orthogonal circular polarization holographic optical data storage... 

Fig. 30. Results of orthogonal circular polarization holographic optical data storage on BR-D96N film by Fourier transformation holographic method, (a) stored file (b) encoded binary monochromic image (c) retrieval diffractive image (d) decoded result (e) retrieved file (1) measurement of size of hologram (one grid of the scale corresponds to lOjim).

Yao, B., Ren, Z., Menke, N., Wang, Y, Zheng, Y, Lei, M., et al. (2005). Polarization holographic high-density optical data storage in bacteriorhodopsin flhn. Applied Optics, 44,7344—7348. 

Nowadays most colorants have the purpose to satisfy our aesthetical needs and, thus, thousands of dyes and pigments are produced on industrial scales. Nevertheless, nearly periodically new demands arise for so-called fimctional dyes whose tt-conjugated systems exhibit novel functionahties beyond aesthetical purposes. Optical brighteners or near-infrared absorbers are examples where even transparency in the visible spectrum is desired and dyes for nonlinear optics, holographic optical data storage and two photon absorption are further examples where the color properties of dyes are insignificantly related to the functional demands. 

Lin Q, Jho JY, Yee AF (1993) Effect of drawing on structure and properties of a liquid crystalline polymer and polycarbonate in situ composite. Polym Eng Sci 33 789-798 Liu YJ, Sun XW (2008) Holographic polymer-dispersed liquid crystals materials, formation, and applications. Adv Optoelectron. 2008. Article ID 684349, 52 pages Matharu AS, Jeeva S, Ramanujam PS (2007) Liquid crystals for holographic optical data storage. Chem Soc Rev 36 1868-1880... 

A potential technological exploitation of the reversible ,Z-isomerization of materials containing azo units has attracted growing attention over the past decade and the subject was reviewed in 1993. A variety of the attempts include liquid-crystal displays and devices, nonlinear optics, optical switching and data storage,holographic grating, etc. 

These fields, where photoalignment technology happens to be useful, may cover the ordering of thin semiconductor layers, thin layers in solar cells, optical data storage, and holographic memory. New, highly efficient photovoltaic, optoelectronic, and photonic devices thus become possible. 

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