This paper presents latest own results in the development of reversible photochromic and irreversible photofluorescent
polymer systems providing fabrication of multilayer recording media for 3D optical memory with super high
information capacity. It was shown that synthesized thermal irreversible photochromic diarylethenes into plastic binders
allow to prepare photochromic polymer layers providing nondestructive refractive read-out of optical information.
These photochromic polymer layers were used for preparation of six-layer recording media tested with the positive
results using the framed optical device. This device imitated layer-by-layer writing, erasure and read-out of optical
signals. Experimental evidences for making photochromic polymer layers based on a mixture of photochromic
diarylethene and dye - phosphor with nondestructive fluorescent read-out are presented too. Polymer systems based on
light-sensitive chromones manifest an irreversible photochemical transformations of these non-fluorescing compounds
into the fluorescent products under UV irradiation. Received results open perspectives for making multilayer optical
discs for bitwise working (based on photochromic systems) and archival (based on irreversible photofluorescent
systems) optical memory with information capacity more 1 TB.
Paper presents results of own development in the field of organic recording media for working (WERM) and archives (WORM) optical memory. Recording media for working optical memory have been prepared with the use of original thermally irreversible photochromic compounds from diarylethenes and fulgimides as well as polycarbonate as a polymer binder. Using these recording media, refractive and fluorescent methods for nondestructive readout of optical information have been elaborated. Aiming at making recording media for archives optical memory organic compounds (chalcone, diarylethene) which formed fluorescent products during irreversible photochemical reaction under laser irradiation were used. Based on developed photochromic materials samples of three-layer photochromic recording media have been prepared and tested with positive results on the developed optical device. This device includes Nd - laser and provides generation of several harmonics of laser irradiation.
At present the main application of holography is the development of holographic optical memory with the super high information capacity. Recent advantages in decision of a number of technical problems associated with making holographic optical devices brought to the fore the question of the development of light-sensitive media of different types (photopolymerizable compositions, dichromated gelatin layers, photorefractive and photoanisotropic materials, etc.) It was shown that there are perspectives of the development of polymerizable materials based on photobleaching photochromogenic and photochromic photo- initiators for archive optical memory with the same information capacity is associated with expected advances in making photoanisotropic polymers containing photochromic fragments.
The analysis of the results of studying photochromic compounds and systems which exhibit reversible photoinduced changes not only in absorption, but another properties as well (irradiation capability, refractive index, light scattering, nonlinear characteristics) is presented. Multi-mode photoelectrochromic systems are discussed too. These photochromic compounds and systems are candidates for modern optical information technologies and molecular photonics.
A review on the development of photoluminescent organic recording media is presented. Particular emphasis has been placed on positive photoluminescent materials for irreversible and reversible recording of optical information. The results of the study of light-sensitive systems based on irreversible and reversible photochemical transformations or organic molecules are discussed. The fundamental characteristics for made photoluminescent polymeric materials based on these photochemical systems and perspectives of their application as recording media, especially in the modern photography and 3D- optical memory devices, are given adequate consideration.
Advances of Russian scientists in the field of the development of irreversible and reversible recording media for holography are discussed. Particular emphasis has been placed on the development of photomaterials for display holography, phototechnology of making holographic optical elements. The result of the study of light-sensitive system and their application in the field of optical memory and processing optical information are presented too.
The analysis of nonlinear optical effects in organic media, namely generation of harmonics of laser radiation, two- photon absorption, and photoinduced birefringence, is presented. The possibilities of their application for recording and processing optical information as well as for transformation of laser radiation are discussed.
Recent advances in the development of a new light-sensitive media for recording, storage of optical information are discussed. Particular emphasis has been placed on the self- developing photochemical materials including media with the luminescent read-out as well as the use of non-linear optical effects for writing optical information.
The review of advances in the field of the development of light-sensitive recording media for archival and working optical memory with a high information capacity is presented. The prospects for making angular- and frequency- selective as well as two-photon optical memories based on organic and inorganic recording media are discussed.
The analysis of available data about properties and possibilities of the Cycolor<SUP>TM</SUP> reproduction technology for preparing color images using the nonsilver light-sensitive media containing microcapsules with photopolymerizable compositions is carried out. The results of our own investigations in the field of the peculiarities of polymerization processes, the method of preparation for microcapsules based on modified liposomes, and compositions for receiver sheet are discussed.
The analysis of the results received during last 5 years in the field of light-sensitive holographic recording media is presented. The lines of the improvement of these media for color display holography, phototechnology for making of holographic optical elements and perspective information optical technologies are determined.
The analysis of the results of the study in the field of organic recording media for making of frequency-selective optical memory is presented. Among these media are polymolecular films based on cyanine dyes and photoinduced merocyanine molecules of photochromic spirocompounds capable to form-aggregates. Besides, media manifesting hole photoburning at low temperatures are reviewed too because of their prospect of the development for frequency-selective optical memory with extreme information capacity.
A review of the latest advances in the field of investigations and applications of photochromic organic systems with practically acceptable properties only is presented. The analysis of the attained results shows that the development of media for the most-used photochromic light modulators is completed essentially. The development of photochromic recording media for working optical memory remains unresolved. The prospects for the development and application of new organic photochromic systems for these applications are closely associated with advances in solution of the problem of fatigue resistance under prolonged irradiation for modulators and optical memory and long storage in darkness for optical memory. Among the new directions efforts to develop photochromic compounds with polyfunctional properties are noteworthy.
The present status of research on some photoinduced phenomena in organic thin films is outlined in relation light - sensitive recording media. Stress is laid on the photoinduced ablation, irreversible photochemical reactions, photochromic transformations, photoanisotropic processes, photoreffactive effects and reversible photochemical reactions in vacuum - deposited, polymeric and Langmuir - Blodgett (LB) films.
The results of the study of photoinduced birefringence processes in different media are reviewed. The application of these results is devices of recording, storing and processing of the optical information and in the phototechnology of making of polarizing optical elements for different function are discussed too.
It is shown that future improvements of light-sensitive recording media for optical storage memory are connected with the increasing of information capacity of photomaterials at the sacrifice of replacing photothermal writing techniques by photochemical ones, two-photon photochemical reactions, frequency-selective writing of optical information, the use of the photoanisotropic phenomenon and the holographic recording method.
The analysis of the results concerning the influence of the molecular organization of microdispersed photosensitive systems upon their properties has been performed. The dependence of characteristics of silver halide recording media and of a number of nonsilver ones of the molecular organization of the structure of the matrix and photosensitive elements has been represented. The investigations of Russian scientists in this field have received special attention.
The analysis of the results obtained from holographic investigation into the region of light- sensitive materials being fulfilled essentially by Soviet scientists has been performed. The advances in the creation of the recording media for imaging holography, for phototechnology in the production of holographic optical elements, of optical memory and optical information processing have been demonstrated. In conclusion, the main expected research lines in the field under consideration have been defined.
This paper is a brief review of original results of investigations and developments of some organic light-sensitive media which provide realization of photoinduced dichroism and birefringence, their applications in optical recording and processing of information, and phototechnology of manufacturing optical elements.
A brief review of the original results of investigations and development of light-sensitive organic materials for optical discs is presented. The photopolymers may be used as substrate materials, clear protective coatings of optical discs, and for their replication. Photoanisotropic organic materials are used as light-sensitive media for recording optical information.