Holographic memory system based on projection recording of computer-generated 1D Fourier holograms

Abstract

Utilization of computer generation of holographic structures significantly simplifies the optical scheme that is used to record the microholograms in a holographic memory record system. Also digital holographic synthesis allows to account the nonlinear errors of the record system to improve the microholograms quality. The multiplexed record of holograms is a widespread technique to increase the data record density. In this article we represent the holographic memory system based on digital synthesis of amplitude one-dimensional (1D) Fourier transform holograms and the multiplexed record of these holograms onto the holographic carrier using optical projection scheme. 1D Fourier transform holograms are very sensitive to orientation of the anamorphic optical element (cylindrical lens) that is required for encoded data object reconstruction. The multiplex record of several holograms with different orientation in an optical projection scheme allowed reconstruction of the data object from each hologram by rotating the cylindrical lens on the corresponding angle. Also, we discuss two optical schemes for the recorded holograms readout: a full-page readout system and line-by-line readout system. We consider the benefits of both systems and present the results of experimental modeling of 1D Fourier holograms nonmultiplex and multiplex record and reconstruction.

Method of Personalization of Photopolymer Security Holograms Based on Recording Hidden Encoded Digital Images

“…At the next stage, the CSFH is reproduced in optical form by means of a liquid crystalline space-time light modulator (STLM) and introduced into a specialized projection-type optical recording system [6][7][8], in which it is projected onto a photopolymer material with necessary ten-to twenty-fold reduction in size. Preliminary calculation results show that if the period of the CSFH structure on an STLM is usually 40-60 μm, then an optical Fourier microhologram with a structure period of about 3 μm is formed on the photopolymer material with a twenty-fold reduction in size, i.e., the structure with spatial frequencies of about 350 mm -1 .…”

A Tribute to Sergey Odinokov

“…The new methods were copyrighted by three patents of the Russian Federation [37,38]. The experimental prototype of the system was built and contained an incoherent projection recorder and an anamorphic optics-based coherent reader [39,40]. The research results were presented at numerous conferences in Russia such as HOLOEXPO and Photonics and Information Optics, and international meetings such as Digital Holography and 3D Imaging 2015 in Shanghai, International Symposium on Optical Memory 2016 in Kyoto, where it was invited as plenary speech, Holography: Advances and Modern Trends 2017 in Prague and many others.…”

Метод Персонализации Фотополимерных Защитных Голограмм На Основе Записи Скрытых Кодированных Цифровых Изображений

“…На следующем этапе КСГФ с помощью жидкокристаллического пространственно-временного модулятора света (ПВМС, SLM) воспроизводится в оптическом виде и вводится в специализированную оптическую систему записи проекционного типа [6][7][8] Считывание скрытых кодированных изображений может осуществляться проекционным методом в обратном ходе, т. е. путем регистрации фотоприемным устройством увеличенного изображения микроголограммы Фурье с последующим цифровым декодированием и восстановлением записанных данных. Технически для регистрации микроизображений можно использовать лабораторный микроскоп либо более компактное устройство с оптической схемой, аналогичной микроскопу.…”