Optical information storage

Compared to photographic films, BR is handicapped due to its very low light sensitivity. Also, as a possible material for disk-shaped digital optical information storage, BR does not offer an advantage over estabUshed magnetooptical materials ia spite of its higher line resolutioa, because ia both cases... 

Optical immunosensors, 3 803, 813 Optical industry, indium in, 14 195 Optical information storage markets, polycarbonate grades for, 19 809-810 Optical isomers, 6 72-73 Optical lens systems, in photography,... 

ABSTRACT A new class of photosensitive, thermally stable polymers containing photo-labile aromatic amide linkages has been prepared. These polymers can be used to provide lithographic relief images for printing, etch masks for microcircuit fabrication and as contrast media for optical information storage. 

Special polycarbonate grades have been developed for the optical information storage market e,g., compact disks. 

H. G. Heller, The development of photochromic compounds for use in optical information storage, Chem. Ind., 1978, 193-196. 

Y. Yokoyama and Y. Kurita, Photochromic fulgides applicable to optical information storage, discovery of new nondestructive readout method, J. Chem. Soc. Jpn., Chem. Indus. Chem., 1992, 998-1006. 

Kurita, S. Takeda, J. Yokoyama, Y. Kurita, Y. Photochromic Fulgides Applicable to Optical Information Storage Tsuruta, T, Ed. Elsevier Amsterdam, 1993 Vol. C, pp. 357- 362. 

Yainane, H., Kikuchi, H., and Kajiyama, T. Laser-addressing rewritable optical information storage of (liquid crystalline side chain copylymer/liquid crystals/photo-responsivc molecule) ternary composite systems. Polymer 40, 4777 (1999). 

Optical information storage, which has been a dream since the discovery of the laser, is now becoming a commercial reality. Read-only consumer products (video and digital audio disks) have provided a solid technological base for the development and introduction of the more sophisticated write-once and erasable recording systems. This chapter will review the current status of polymeric materials as substrates, protective layers, and active recording media in laser recording. 

Case Study 6.4 Optical information storage - photochromic diarylethenes... 

On the other hand, liquid crystalline polymers applied to optical information storage has attracted great attention. The liquid crystalline polymer is applied mainly in terms of the thermo-optical effect. The backbone of liquid crystalline polymer can be polysiloxane, polyacrylate, or polyesters. In order to enhance the absorption coefficient for the writing laser beam, the dyes may be either dissolved into the liquid crystalline polymer in the guest-host model or attached to the backbone of the liquid crystalline polymer to form a copolymer. The nematic, cholesteric and smectic liquid crystalline polymers are all be able to be utilized in optical information storage. 

Figure 6.45 is a schematic of optical information storage which applied a nematic liquid crystalline polymer with a glass transition Tg, less than... 

Figure 6.45. The schematic of optical information storage by nematic polymer.

Ueno s group studied the erasable cholesteric optical information storage display. They used the semiconductor pulse laser (power 18 mW) instead. A definition of 1.5 microns was achieved. 

Figure 6.47. A cholesteric polysiloxane copolymer applied in the optical information storage application.

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