Analysis of holographic data storage using a PA-LCoS device Francisco J. Martínez 1,2 , Andrés Márquez 1,2,* , Sergi Gallego 1,2 , Sandra Fenoll 1,2 , Manuel Ortuño 1,2 , Jorge Francés 1,2 , Sergio Bleda 1,2 , Inmaculada Pascual 2,3 1 Dept. de Física, Ing. de Sistemas y T. Señal, Univ. de Alicante, Ap. 99, E-03080, Alicante, Spain 2 I.U. Física Aplicada a las Ciencias y las Tecnologías U. de Alicante, Ap. 99, E-03080, Alicante, Spain 3 Dept. de Óptica, Farmacología y Anatomía, Univ. de Alicante, Ap. 99, E-03080, Alicante, Spain ABSTRACT Holographic data storage systems (HDSS) have been a promising and very appealing technology since the first laser developments in the sixties. Impact of ongoing advances in the various components needs to be explored in its specific application to HDSS. In this sense, continuous progress is being produced in spatial light modulator (SLM) technology where parallel-addressed liquid crystal on silicon (PA-LCoS) microdisplays have replaced previous liquid-crystal displays (LCD) in most of optics and photonics applications. PA-LCoS microdisplays are well adapted to display phase- only elements without coupled amplitude. In this paper, we analyse how PA-LCoS devices can also be used to display the widely applied binary intensity modulated (BIM) data pages. We also investigate hybrid-ternary modulated (HTM) data pages, which are very much demanding on the phase and amplitude modulation properties of an SLM. HTM data pages combine the ease of detection of BIM data pages, together with a large reduction of the DC term of the Fourier Transform of the data page. This reduction is necessary to avoid saturation of the recording material dynamic range. Simulated results show the magnitude of the expected DC term in the Fourier plane. We have verified the good performance of PA-LCoS to display BIM data pages. We have also obtained that pure HTM data pages cannot be produced with PA-LCoS devices, however, a rather close performance is obtained when implementing the pseudo-HTM data pages. In this work a more complete study of pseudo-HTM modulation is offered. Keywords: Holographic and volume memories, liquid crystal on silicon displays, parallel aligned, spatial light modulation. 1. INTRODUCTION Holographic data storage systems (HDSS) need an entry data point. They use a spatial light modulator (SLM) that allows to change the data dynamically. Parallel aligned liquid crystal on silicon devices (PA-LCoS) have been widely used as SLM. They offer an easy operation as phase-only device, and they can be easily used as amplitude only devices. These features bring us the opportunity to select the modulation regime required by our application. PA-LCoS have been found useful in many applications as in diffractive optics [1] , optical storage [2] , optical metrology [3] , reconfigurable interconnects [4][5] , or quantum optical computing [6] , due to their very high spatial resolution and very high light efficiency [7][8] . PA-LCoS displays can be assimilated to linear variable retarders [7][8] , but they exhibit some flicker or fluctuations [9]-[14] , specially digitally addressed backplane devices [15][16] which are widely used. Then, for a full characterization of the PA- LCoS device, the retardance and the fluctuation amplitude will be needed. To this goal some techniques, based on simple polarimeter setups, were developed by our group and Ramirez et al. [17]-[19] . A more detailed characterization was obtained by applying time-average Stokes polarimetry [20] . Using a Mueller based model we can predict the response of the device for every gray level and any kind of state of polarization (SOP) at the system entry. In the present work, this method is used to predict the performance of a specific modulation scheme for data pages. We analyse how to use PA-LCoS devices to display binary intensity modulated (BIM) data pages. We also investigate hybrid-ternary modulated (HTM) data pages, which are very much demanding on the phase an amplitude modulation properties of an SLM. We have verified the good performance of PA-LCoS to display BIM data pages, and we have also observed that pure HTM data pages cannot be implemented with PA-LCoS devices, however, a rather close performance Optical Modelling and Design IV, edited by Frank Wyrowski, John T. Sheridan, Youri Meuret, Proc. of SPIE Vol. 9889, 988922 · © 2016 SPIE · CCC code: 0277-786X/16/$18 · doi: 10.1117/12.2227948 Proc. of SPIE Vol. 9889 988922-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 09/05/2016 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx