52
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OPTICAL CARRIER FOR LONG-TERM DIGITAL INFORMATION STORAGE in the
electro
V.V.Petrov, A.A.Kryuchyn*, S.M.Shanoylo
The i;
Inst, tor Information Recording, 03113 Kyiv, Ukraine, 2 Shpak Str. - petrov@ipri.kiev.ua analog
and in
on a n
KEY WORDS: Digital.Optical.Archiving. Photographic Recording and Documentation. Relief-Phase Method optica
radiati
techni
ABSTRACT: carriei
inforn
The task for providing the reliable and long-time storage of digital content is getting more and more actual and important. This is bound 4.7 M
up with the transition to a digital form of the information storage in all spheres of the human activity: education, culture, science, banking, be ref
medicine etc. The transition to a digital form of the information representation presumes the provision of its long-term and reliable optica
storage. The digital information content, subject to the long-term storage, is growing fast both at the expense of accumulating new data optica
and at the expense of digitizing archival materials. Large potentials on providing long-term and reliable digital information storage have carrier
the optical methods of information recording and reading. These potentials are determined by the following reasons: absence of contact
with information recording/reading systems, resistance of optical carriers to the influence of electromagnetic fields, possibility of using The cl
the information representation in the form of microrelief structures on the surface of homogeneous substrates, high protection of an condit
information layer against mechanical contaminants at the expense of focusing the recording/reproduction radiation through a transparent -nicke
substrate. Besides the optical recording methods provide high densities of information registration. The main task at developing optical the sal
carriers for long-time information storage consists in choosing and synthesizing high-stability materials for optical carriers and methods -the h
of applying information on them in the agreed-upon data representation formats. In work the opportunities of using metal carriers for inforn
optical information registration systems and methods of information application on them are analysed. condit
-the h
carrier
1. INTRODUCTION storage, is the use as substrates of polymer materials subject to The rr
time changes of physico-chemical properties and having low safety
Over several centuries the main means for information storage mechanical and thermal strength. One of the most steady polymer
was paper. The service life of high-quality paper is 400-500 years, materials is the polycarbonate which is a base material for CD There
what allowed in libraries, archives, museums to keep a large manufacturing. But its mechanical strength limits reading rate of term s
volume of knowledge created by mankind. However analog form information from CDs. The reliability of information storage on The cr
of the information representation on paper carriers does not optical carriers can be essentially increased at replacement of were '
provide a timely access of a large number of users to information, plastic substrates by metal or glass substrates. On such carriers an specia
to use multimedia information representation, besides paper information layer should be formed in the substrate itself as a qualit;
carriers are gradually broken down. An agreed-upon form of relief microstructure. (60%)
solving a problem of providing a timely access to infonnation ellipse
resources, introducing into the scientific circulation of archival 2. TECHNOLOGY OF MANUFACTURING CARRIERS manul
materials and their preservation is the representation of documents FOR LONG-TERM STORAGE t * ieir 1
in a digital form (Buchel, 2002; Arndt, 2002). The digitization of on jy '
archival materials is desirable to make once and for all. The The modem optical disks can ensure the term of infonnation thickn
carriers of archival storage should have such basic perfonnances: storage not more than 50 years. It is bound up with the instability
-term of storage, corresponding to lifetime of high-quality paper; of properties of polycarbonate substrates and the use of multilayer invest
-high recording density, as a minimum corresponding to the thin-film structures for information recording. Even with such micro:
standard CD recording density; service life the optical disks, primarily CD-R, can be used for spectr
-to use a form of information representation which allows to read creation of electronic libraries, digital archives, databases. The surfac
it by different methods. large terms of storage can be ensured at the expense of the contei
periodic transfer of infonnation (such an opportunity of transfer impur
Currently different types of carriers for long-term storage of without deterioration of quality is provided with the digital
digital information: magnetic tapes, microfilms (it is supposed to information representation) or at the expense of increasing the Dunn
use them for infonnation storage both in digital and analog forms) stability of information carriers properties. The increase of service signifi
and optical disks are analysed and developed. All of them have a life of optical disks is supposed to achieve (HD-Rosetta, 2001; has in
term of guaranteed storage of information no more than 50 years Kryuchyn, 2002) at the expense of making a carrier in the form of equipi
(Calmes, 1993; Adelshtein,1999). The carriers with such service a nickel disk with the information representation in the form of impur
life can be used as an intermediate link for digital information submicron-size recesses on its surface. The images on the surface replie,
recording with the subsequent transfer of a part of information on of a nickel carrier can be formed by a method of full t!ian
carriers having a longer, as a minimum on the order, term of bombardment (HD-Rosetta, 2001) or formed by laser of gra
storage. Large capabilities for essential increase of term of storage photolithographic techniques used in the technology of estime
have optical carriers, especially with the relief-phase manufacturing stampers for CD replication. On the glass carriei
representation of infonnation. One of major factors limiting the substrate is applied a positive resist layer on which information is
term of information storage on carriers, provided for long-term recorded by a focused laser beam at the speed of (300-600) KB/s.
