Optimization of a 1 mm thick PVA/acrylamide recording material to obtain holographic memories: method of preparation and holographic properties

Abstract

ORTUÑO, Manuel, et al. "Optimization of a 1 mm thick PVA/acrylamide recording material to obtain holographic memories: method of preparation and holographic properties". Applied Physics B: Lasers and Optics. Vol. 76, No. 8 (July 2003 AbstractInformation holographic storage is a very promising technique due to its high theoretical capacity. One of the key factors in developing holographic memories is the need for a suitable recording material which must have certain specific characteristics. In particular, in order to achieve a high storage density it is necessary to work with great thicknesses. One of the essential requirements for holographic memories to be competitive is that the material must have a thickness of 500 µm or more, but it is not easy to find such thicknesses with the photopolymers currently available. In this study, we develop a method of preparing layers of a polyvinyl alcohol/acrylamide based photopolymer approximately 1 mm thick. Optimization of this material makes it possible to obtain good results for the main holographic parameters; diffraction efficiency 70% and energetic sensitivity 50 mJ/cm 2 .PACS numbers: 42.70.Ln; 42.40.Pa; 42.40.Ht ORTUÑO, Manuel, et al. "Optimization of a 1 mm thick PVA/acrylamide recording material to obtain holographic memories: method of preparation and holographic properties".

Anamorphic characterization of a PA-LCoS based holographic data storage system

“…When we introduce the photopolymer, new sources of distortion appears. We use a Polyvinyl Alcohol Acrylamide (PVA/AA) photopolymer developed and manufactured by our group 18 . During the manufacturing process, ripples on the surface can be introduced and deformations due to continuous exchange of water molecules with the environment, as well as the natural crystallization process may affect the recording process 18 .…”

Holografía: ciencia, arte y tecnología

“…En nuestra sociedad, dominada por las tecnologías de la información, la utilización de la holografía en el almacenamiento de información es una de las aplicaciones que presentan en estos momentos más futuro e interés [55,56]. Mediante el multiplexado se puede registrar un gran número de hologramas en una misma placa y posteriormente es posible recuperar la información separadamente.Éste es el principio de las memorias holográficas [57] en las que se puede almacenar en poco espacio una gran cantidad de información. Aunque las mayores dificultades técnicas para llevarla a la práctica han estado relacionadas con la obtención de un material de registro adecuado, ya se han fabricado los primeros prototipos de sistemas de almacenamiento holográfico con discos holográficos con una capacidad de almacenamiento de 300 Gb, el equivalente a más de sesenta DVDs en un solo disco, y se sigue investigando para obtener mayores capacidades de almacenamiento, incluso del orden del Tb.…”

New trends on photopolymers

“…If the viscosity is too high to use a magnetic stirrer, we stir slowly by hand to prevent the formation of air bubbles, followed by the application of a vacuum to both the prepared solution and the coated mold so that any eventual air bubbles are completely eliminated. 7 The solutions are deposited by gravity, in polystyrene or poly(methylmethacrylate) molds, and left in the dark to allow the water to evaporate , while recording the laboratory conditions (temperature and relative humidity, RH) during the process. When part of the water has evaporated, the dry material is removed from the mold, cut into squares and adhered, without the need for adhesive, to the surface of glass plates measuring 6.5×6.5 cm.…”

“…5,6 In this respect, our research team has developed a photopolymer in layers 1 mm thick for use as a holographic memory, and its main holographic characteristics have been evaluated. [7][8][9] The main drawback of an AA-based photopolymer as far as the environment is concerned is the acrylamide, a substance which has been known to be carcinogenic for many years. Recent investigations confirm the toxic potential of AA.…”