Dichromated polymer materials prove to be efficient real-time holographic recording materials which involve no thermal or chemical development. Volume transmission holograms have been recorded in Dichromated Poly(acrylic acid) (DCPAA) recording medium and by angularly multiplexing technique, twenty holograms have been stored in one specific area with equal diffraction efficiency. A discussion is made about the optical neural networks, holographic optical interconnection, and holographic multiplexing.

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.

Bacteriorhodopsin (bR) originating from the purple membrane of the bacterium Halobacterium Halobium has been extensively studied during the last few years for a number of optical applications. Extending the lifetime of the intermediate M-state in bR chemically, has been found to improve the sensitometric properties of bR. In this paper, a new method of extending the lifetime of the M-state in the bacteriorhodopsin photocycle is presented. The method pertains to the use of 18- crown-6 ether as an agent to extend the M-state lifetime.

Optical characteristics of dynamic lens formed by light in the photoreversable medium are considered. The results of investigating non-linear optical crown-ester-based photoreversible media are presented. The use of the crown-ester-based photochromic medium is shown to enhance the resolution of an optical-addressing system almost by an order of magnitude.

The possibility of using solid solutions of the trichromophore as the active surrounding in systems of optical processing of information is analyzed. It is shown that such a system allows the realization of the function for recording optical information. It should be noted that the recording and reading of optical information by light field are of the same spectral constitution.

The design principles of inexpensive compact holographic read-only memory (CHROM) based on plastic card and its construction are discussed. CHROM memory volume equals 2...10 MByte.

Photopolymer material (PPM) is the organic I i ght-sensi tive medium. Due to light irradiation the polymerization of the initial monomer occurs causing the refractive index change. Therefore these materials al low the phase hologram recording with the high diffraction efficiency (DE). PPM used in holography can be separated by the three types : - Ii quid PPM based on the I i quid monomers which polymer1zatlon takes place between two plate glasses, - solid PPM with polymer matrix photocross- linking, - amorfous PPM containing matrix polymer fi Im and monomer, initiator and sensibilizator. Liquid arid sol i d PPM are elaborated for holography E 1-4], but they are used for a long time in the field of microelect ronics, reprography arid other photoprocesses. Amorfous PPM was created especially for holographic purposes. It attracts users by the real- t i ne record I ng, fac I I I ty of nter I al deve 1opnnt without any wet process. PPM described in E 5, 6) and PPM of' Du Pont De Nemours [7] are the nteria1s of this kind. In the present paper the chemical approach in the elaboration of anrfous PPM for the hologram recording by the HeNe- laser I s descr I bed. The pecul I ar i t i es of the recording process i n the new PPM are also dIscussed.

The possibility of optical information storage in sodium-tellurite glasses is demonstrated. The optical recording is based on the phenomena of the photoinduced second harmonic generation in glasses (PSHG). A microscopic model of this optical recording is suggested. The model is based on the analysis of optical transitions in nonbridging oxygen centers (NBO) (0.26 and 0.62 micrometers absorption bands and 0.65 micrometers photoluminescence band) in the frames of two-well adiabatic potential of NBO ground state. During simultaneous glass irradiation by YAG:Nd laser (1.06 micrometers ) and its second harmonic (0.53 micrometers ) the multiphoton 0.26 micrometers absorption in NBO band (under interference four- three- and two-photon processes) with subsequent photoluminescence leads to NBO moves from one stable position to another and to the recording macroscopic (Chi) ⁽²⁾-grating.

Free volume diffusion induced by photochemical reaction in glassy polymeric matrix is investigated. It causes significant density and refractive index variations leading to phase hologram enhancement in freshly prepared or heated photosensitive layers and opens the possibility of implementing photothermic optical recording. The calculating model of photoresponse formation is proposed and the results of numerical simulations are presented.

As an alternative to recording media on the tellurium base, recording media built in the form of matrix structures in which a photo(thermo)active component is included into the matrix can be used. We suppose that the most effective preparation method of such media which provides the deposition on substrates of any form can be a dissociation method of organometallic compounds (OMC). Depending on the choice of OMC, atmosphere in which occurs its decomposition, additions and conditions of process following there can be obtained by polymerization of OMC ligands in which is distributed a metal phase (metal-polymeric media) and an oxide matrix in which are implanted organic ligands changing its parameters. The gradient metal spreading was created by increasing the pulse amplitude of voltage discharge from 500 to 2000 V. The content of metal was increased in direction from substrate and was near substrate 0 - 10 at percent and near free film surface up to 80 at percent. The film composition was investigated by means of the layer-to-layer auger analysis using microscope JAMP-10 S. The comparative analysis of Raman spectra of starting OMCs and prepared from them films showed the advent of new bonds of the type metal-metal, carbon-carbon and the decrease of bonds quantity of the type carbon-carbon, metal-ligand. The action of focused laser radiation on such films leads to formation of microholes in the center of the irradiation region and on peripheral areas it leads to an additional OMC decomposition.

The theoretical 3D models for designing and developing acousto-optic components (modulators, deflectors) based on nonuniform crystals are represented. The influence of temperature induced 3D optical inhomogeneities on performance parameters of acousto-optic components including distortions of 2D amplitude-phase profiles and polarization parameters of light beams is discussed and illustrated by the analytical calculations and the detail numerical modeling results.

The method of measuring phase characteristics of dynamic carriers is considered. BR photoinduced isomerism influence on the refractive index of BR-based carriers is studied. The photoinduced change in refractive index of the BR-based photocarrier is shown to reach 3.5 (DOT) 10^-4 at wavelength 0.44 micrometers .

Some properties of a pseudodeep hologram are considered as applied to the problems of optical computing. It is shown that the diffraction efficiency of this type of hologram can be increased by means of increasing the inclination factor of rays that intersect the light-sensitive layer. The results of the experiments are presented.

Conventional recording of information by holographic methods, such as Fourier transform holography, does not use efficiently the storage capacity of the recording medium. Employing hybrid electro-optical methods of optimization can substantially increase the affectivity and flexibility of information storage. Examples of algorithms and applications related to pattern recognition, holographic storage and the design of three-dimensional light distributions are described.

The reasons for the spatial information filling factor limitations in holographic memory devices (HMD) are analyzed and the significance of a recording medium dynamic range among those factors is estimated. Connection between the information filling factor and dynamic range are investigated for different recording media.

Light power spent per information unit in the holographic memory is evaluated. Connections between the separate components of this power are established. It is shown that quantum efficiency of information which is sampled consecutively appears to be small if the retrieval rate of the separate bit of information is high. The value of the information unit quantum efficiency grows sufficiently if the retrieval of the word or image is parallel.

Molecular electron memory with shift register based on a polymer storage medium with a photoinduced electron vector transfer reaction is considered. The method for computing such a memory and structural circuit, operation algorithm, the delay parameters of the memory based on VLSI and a homogeneous molecular storage medium are presented.

The principles of recording nonstationary interference structures on a moving photosensitive medium are discussed. An optical circuit enabling recording of Fourier holograms that ensures synchronism of movement of interference fringes and recording medium is described. Experimental results are given illustrating the recording of two-dimensional holograms on a moving medium. The possibility of recording such holograms at the rate of up to 10³ holograms per second is demonstrated.

For optical memory based on reversive photothermoplastic information carriers, a hologram recording mechanism for short expositure time (to picoseconds) and high-photosensitivity photothermoplastic materials for holographic information recording are considered. It is shown that the latest achievements in the branch of high-sensitive (10^-6 J/cm²) materials and multielements high-speed (response time of 200 kHz) liquid crystal 1D modulators with 1000 elements allow us to achieve for real optical memory systems based on moved film carriers the data rate of 28 Mbytes/s and storage capacity of 3 Gbytes. The limit opportunities of such memory are considered. The described memory can be used with high-speed correlative or neural-network information processing.

In the paper, issues of using combined holographic media with recording static and dynamic hologram for high-capacity storage are discussed. Some peculiarities of reconstructing holograms by two or more reconstructing light waves in combined medium based on bacteriorhodopsin are considered. The interaction between two plane waves and volume grating that is the sum of static and dynamic ones is studied. It is shown that the multibeam scheme of reading allows us to achieve considerable amplification of diffracted waves, improvement of hologram reconstruction selectivity, and increase of the capacity of the holographic information carrier.

A new approach to the design of the holographic disk memory system which consists in recording a sequence of expanded 1-D Fourier-holograms overlapping each other along the ring tracks on the storage carrier surface is considered. This approach allows moderation of requirements to focusing and positioning of the laser beam as compared to CD with point-by- point recording technique or disk systems with 1-D narrow Fourier-holograms.

Four-wave photorefractive parametric interactions in lithium niobate planar optical waveguides with advanced photorefractive sensitivity have been observed and experimentally studied. Photorefractive gratings of arbitrary periods at using the extraordinary radiation mode as a pump have been obtained in such interactions.

Optical waveguides in melts of benzoic acid with the addition either of copper or iron oxides have been fabricated and two-beam recording of holographic gratings due to the photorefractive effect have been realized in waveguides produced.

The problem of the optical memory using the long-lived photon echo is analyzed. The results of our experiments on this problem are discussed.

Until recently, optical fibers were used in optical communication systems only as a passive transmission medium. However the discovery of refractive index photoinduced gratings and second-order nonlinearity together with the development of fibers with length-varying dispersion allows the processing of information during its transmission along fibers.

The method of enhancing the information capacity and reliable storage of information in circulator fiber-optic memory is presented. The method is based on creation of an additional built-in channel with contrary-directed circulation of signals. This channel can be used for transmission of both information and auxiliary signals: address words, clock signals, correcting sequences, etc. The possibility of compensating the information signal losses by means of stimulated Raman scattering is considered.

A new ultrashort bit carrier called the guiding-center soliton is used to shape and to store the multibit binary words. The essential property of such a carrier to return to its own initial width after a passage through an extremely long-haul fiber without any recovery is successfully exploited to advantage. It is experimentally demonstrated that semiconductor laser source generated 32-bit words, including picosecond optical guiding-center soliton pulses, could be stored in up to 250 km length single-mode fiber loop.

A new all-optical lumped regenerator for the fiber-loop memory system is presented. The semiconductor device fulfills an extremely precise recovery of the amplitude, width, and shape of initially soliton-like but then distorted in a fiber-loop picosecond optical pulses, so enhanced number of restoration cycles in the memory system can be produced. The reason is all- optically implemented digital type of bit pulses recovery, which is conditioned by a total `stabilization effect' relative to all over the parameters of ultrashort pulses with sech-like shape. Two versions of lumped regenerator design are developed, numerically estimated and compared with each other.