Nina M. Verenikina

Application of optoelectronic micro-displays for holographic binary data recorder based on computer generated fourier holograms

Present article highlights the researches provided during the development of holographic memory system based on application of computational methods to encode binary data pages as amplitude computer generated Fourier holograms (CGFH). Using electro-optical micro-display and projection optics CGFH can be recorded onto photosensitive medium. The type of display that is used in data recorder determines the specificities of optical scheme architecture with its own limitations and advantages. There are three projection schemes of binary data recorder discussed in the paper. A linear scheme based on transparency-type liquid crystal spatial light modulator (LC SLM), a scheme based on reflection-type liquid crystal on silicon spatial light modulator (LCoS SLM) which uses a beamsplitting cube, and the most compact and simple scheme based on self-emitting OLED-display. The results of experimental implementation of all the three projection schemes for CGFH of binary data pages record onto the holographic carrier and consequent optical reconstruction and analysis of the encoded data are presented.

Research of a method and optical system for recording multiplex holograms in a system of holographic memory

The new modified holograms multiplexing method using normal to holographic recording media reference beam incidence and off-normal signal beams incidence is offered for application in holographic memory system having high information capacity and high data rate. Signal beams are located around reference beam concentrically. In this case quantity of multiplex holograms in the same area of recording media is equal to quantity of signal beams. Experimental holographic memory system model applying offered method is tested. Possibility of multichannel optical head application for data recording and retrieving is shown. Offered multiplexing method advantages consist in following: obviating of the necessity of recording media rotation; crosstalk noise free restored data page images; possibility of thin holographic recording media application.

Analysis of data recorder optical scheme impact on quality of computer generated Fourier holograms in holographic memory system

Holographic memory systems provide such advantages as long data storage term, high data density and do not need a power supply. Instead of recording interference pattern, it is proposed to record computer generated 1D Fourier holograms (CGFH). High information density is reached by multiplexing 1D Fourier Holograms. In this work factors, which impact the quality of recorded CGFH are analyzed in mathematical modelling and experimental researches.

Optical memory system based on incoherent recorder and coherent reader of multiplexed computer generated one-dimensional Fourier transform holograms

The present article highlights the development results of archive memory holographic system based on application of computer generated Fourier holograms. The proposed idea allows realization of holographic principles of digital data record using simple and compact optical devices. Special interest is paid to synthesis and multiplexed record of one-dimensional Fourier transform holograms. The principal schemes of constructed prototypes of incoherent data recorder and coherent data reader are described in the present paper. The results of experimental implementation of the constructed devices are presented.

Computer Generated Fourier Holograms Application for Projection Type Holographic Memory System

The specificities of synthesis, record and reconstruction of computer generated Fourier-microholograms for application in projection type holographic memory optical system are discussed. Also we represent the computer generated 1D-Fourier holograms suitable for multiplexed record.

Holographic memory based on computer generated Fourier-holograms

Classic holographic memory systems use two-beam approach based on fixation of interference pattern between object and reference coherent beams on holographic recording medium. The size of single pattern is about several micrometers. High precision optical set up is required to form such a microhologram, that is the reason of excessive price for holographic recording devices. Methods of computer holographic synthesis allow to calculate holographic patterns numerically as 2D images. These images can be realized with the use of spatial light modulator, then reduced in optical projection system and exposed on holographic medium. In this paper we represent the research of holographic memory system based on computer generated Fourier holograms projection.

Development and investigation of a method and optical system for obtaining multiplex holograms in archival optoholographic memory systems

A microhologram-multiplexing method that makes it possible to increase the rate at which information is recorded and read out is proposed and investigated. An optical system for implementing the given method has been developed and experimentally tested. It is shown that holograms can be multiplexed by using a multichannel recording head, and that they can be read out simultaneously by using a multichannel readout head. The proposed multiplexing method and the optical system developed for creating archival optoholographic memory systems have the advantages that there is no need to mechanically displace the elements of the system during multiplexing at the recording stage nor during reconstruction of the multiplexed holograms, that there is no crosstalk in the beams reconstructed from the multiplexed holograms, and that relatively thin recording media can be used for recording.

Scheme and technical implementations of highly effective vector-matrix multipliers for an optoelectronic large-scale neurocoprocessor

Various scheme and technical implementations of a vector- matrix multiplier for neuronetworks design are considered. Variants of the VMM laboratory model on the basis of the traditional optics and standard optoelectronic components are worked out. Input and output vectors are realized accordingly as radiation source and photodetector matrices; weights set with the help of a projector LCD. Possibility of an integrated optical VMM implementation as a monolithic circuit is considered; peculiarity of a planar circuit working is noted. The results of circuit elements calculations and complete VMM circuit arranging with a control block diagram are presented. This neurochip is made on the GaAs substrate by means of the traditional semiconductor technology (0.35 mkm) and takes 40 X 10 mm2 area.

Laser visualization system for intermediate product material heterogeneity

The possibility of visualization of anomal crystallization zones in polymeric material intermediate products by using an optical-electronic model of a test bench has been shown. The visualization is necessary during following production stages: the periodical technical process control, the sample control and the waste rejection. An original scheme of the model construction providing a solution of the raised problem by means of a minimal device composition has been suggested. The model experimental researches for different light sources of the visual and infra-red spectral ranges and different illuminators have been carried out in order to determine an influence of the lighting conditions and light spectral composition on the heterogeneity image quality. The results have permitted to formulate demands to the light source and forming illumination system of the test bench reasonably. The main attention has been given to the diagnostics of the heterogeneity near the top of the intermediate product that is the most typical, difficulty measured, and that exerts essential influence on the product quality. The investigation results for two intermediate product groups of different firms are given. A comparison method of the crystallization zone sizes with the technological norm has been suggested.

High-efficiency vector-matrix multiplier for large-scale optoelectronic neuro-coprocessor

Designed circuit of the large-scale high-efficiency optoelectronic vector-matrix multiplier and its components are considered in terms of geometrical optics. The results of aberration calculation are given to show the absence of cross distortions in both cascades of the system composed of the commercially available optoelectronic elements.