Elena Lvovna Alexandrova

Polyimides: new properties of xerographic, thermoplastic, and liquid-crystal structures

Sensitization of various structured polyimides in the wavelength range 400-750 nm has been studied. Injection sensitization with thin films of nanocrystal CdSe, structural-chemical sensitization with active acceptors, as well as spectral sensitization with various dyes have been investigated. It has been concluded that the application of polyimides as a photosensitive medium allows characteristics of numerous devices to be improved.

Real-time optical information recording using molecular photothermoplastic heterostructures

The photothermoplastic (PTP), photo- and thermoplastic molecular heterostructure materials, which are based on the new principles ofthe donor-acceptor sensibilizations, real-time optical processing methods, the PIP recording cameras, and optical information processing devices with new properties are considered. It is shown that such molecular heterostructure materials have high values of photosensitivity (20 to 100 ASA) and line resolution (above 600 line pairs/mm) and reversibility of over 1000 cycles. For a consistent recording regime a high reproducibility of parameters is achieved. The practical applications of PIP recording for operational holographic memory devices and optical modulation and bit recording systems are analyzed.

High-speed and limited capacity optical disk memory based on three-dimensional microhologram recording on photothermoplastic storage media

The opportunities of the creation of the high-speed (to 109 bits/s) holographic disk memory having a diffraction-limited capacity (to 2 - 40 Gbytes per 1 disk) are shown. This memory is based on the 3D-recording of the multiplied microholograms on the photothermoplastic carrier. New abilities of recording, storage and processing systems based on such memory are considered.

Quantum gains of photophysical processes in media based on organic molecular charge-transfer complexes

For main classes of molecular charge-transfer (CT)-complexes used for xerographic media, the regularities of the changing of the gains of photoprocesses are estimated. It is shown that for homological arrays of CT complex molecules having a constant CT distance, a parameters of photoprocesses (such as a optical CT degree, dipole moment, quantum gains of thermalized coulomb connected pairs and of free charge carrier photogeneration) are connected uniquely with a energy and space parameters. Established regularities allow to predict a unknown values of gains for known-structure CT complex molecules and to estimate a limit value of photoprocesses gains and photosensitivity of media based on CT complexes and photoprocesses mentioned above.

High-photosensitive optical information carriers based on the avalanche phenomena of charge carrier in amorphous semiconductor

For amorphous analog of trigonal selenium, a avalanche phenomena in strong electric field is investigated. It is shown, that it is perspective for supersensitive optical information carriers and it is problematic for xerographical photoreceptors.

New photothermoplastic information carriers having intrinsic raster for low-contrast grey-level image recording

A new type of the photothermoplastic information carrier having an intrinsic raster of 400 mm-1 is created. It is able to record a low-contrast, high-resolved grey level images. It is shown, that developed photothermoplastic carrier is perspective for real-time structural analysis of aero-space images, for coherent-optical processing systems.

Wide-temperature surface and bulk electro-optical effects in thixotropic layers

In work we discovered a surface electrooptical effect for thixotropic layers. It is an appearance of the surface microrelief which dues to a dynamic scattering of light caused by its relief-phase modulation by the formed surface microrelief. Temperature range of this effect existence is very wide (from -80 degree(s) to +80 degree(s)C). Latter is distinguished from limit range of dynamic scattering effects for liquid crystal (from units to tens degrees). The aim of this paper is to investigate the nature of effect mentioned above and to consider its uses for different branches.

Real-time photothermoplastic 8-inch camera with an emphasis on the visualization of 3D digital data by holographic means

The development and investigations of large-formate (8-inch) real-time photothermoplastic (PTP) camera are carried out. The PTP camera is applied for operative recording of 3D- images by means of compound and digital holography and visualization of these holograms as 3D-static images. The optimization of the recording regimes is fulfilled with use the model of the relief-phase PTP images thermodevelopment, proposed by authors. According with that model, the achievement of maximal value of deformation (diffraction efficiency) is based on the opportunity in increasing of charge contrast of electrostatic latent image formed early by the moment of the viscosity decreasing during the thermodevelopment process. It is achieved by means of the control of the thermodevelopment regime. Also, the opportunities of the increase of the camera size (to 14 inch), of the rising of photosensitivity value and the enlarging of its spectral range, of the creation of Benton holograms and of the increasing of the speed of response to 25 Hz are discussed.

Photothermoplastic optical memory with high data rate

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.

Relief-electro-optical transparent medium for optical information processing

We found (to our knowledge) for the first time the compressible dielectric material (gel) for production of thin (100 - 300 micrometers ) transparent films exhibiting relief electro-optical compression effect: the decrease of thickness in an electrostatic field leading to the change of an optical path length. The change equal to visible wavelength is characteristic of 100 micrometers -film with transmittance exceeding 90% and with spatial resolution about 20 - 50 mm-I and response time -25 Hz.