In a holographic optical learning network, the decay of multiply exposed holographic interconnections can adversely affect the training of the network. A new dynamic photorefractive holographic memory is described that allows an arbitrarily long sequence of adaptations by rejuvenating decayed holograms with a simple all-optical feedback loop.

The contribution of holographic techniques to particle velocity measurements is discussed. Two-dimensional holographic particle image velocimetry and three-dimensional holographic velocimetry are described and compared. Their advantages and limits are discussed and the latest progress in this domain is presented, together with perspectives for the near future.

Photopolymers have proved to be useful for different holographic applications such as holographic data storage or holographic optical elements. However, most photopolymers have certain undesirable features, such as the toxicity of some of their components or their low environmental compatibility. For this reason, the Holography and Optical Processing Group at the University of Alicante develope...

Holographic optical element has a high diffraction efficiency and a narrow-band frequency characteristic, and it has a characteristic that is able to implement several features in a single flat device. It is widely applied in various fields. In this chapter, the principle and characteristics of the holographic optical elements are described in detail, and few typical holographic optical element...

Holographic recording in thick photopolymer layers is important for application in holographic data storage, volume holographic filters, and correlators. Here, we studied the characteristics of acrylamide-based photopolymer layers ranging in thickness from 250 microm to 1 mm. For each thickness, samples with three different values of absorbance were studied. By measuring the diffraction efficie...

Recent progress in the development of holographic gratings for neutron-optics applications is reviewed. We summarize the properties of gratings recorded in deuterated (poly)methylmethacrylate, holographic polymer-dispersed liquid crystals and nanoparticle-polymer composites revealed by diffraction experiments with slow neutrons. Existing and anticipated neutron-optical instrumentations based on...

Valiant’s theory of holographic algorithms is a novel methodology to achieve exponential speed-ups in computation. A fundamental parameter in holographic algorithms is the dimension of the linear basis vectors. We completely resolve the problem of the power of higher dimensional bases.We prove that 2-dimensional bases are universal for holographic algorithms. © 2009 Elsevier B.V. All rights res...

Photopolymer materials are widely used in many holographic applications because of their advantages. This paper reviews the various holographic applications which either require the high index modulation including optical demultiplexer, color-display filter, and polarization-selective element, or need the stability and long life such as holographic memory and security card system.

Holographic algorithms with matchgates are a novel approach to design polynomial time computation. It uses Kasteleyn’s algorithm for perfect matchings, and more importantly a holographic reduction. The two fundamental parameters of a holographic reduction are the domain size k of the underlying problem, and the basis size l. A holographic reduction transforms the computation to matchgates by a ...

Holographic gratings formed in thick phenanthrenquinone- (PQ-) doped poly(methyl methacrylate) (PMMA) can be made to have narrowband spectral and spatial transmittance filtering properties. We present the design and performance of angle-multiplexed holographic filters formed in PQ-PMMA at 488 nm and reconstructed with a LED operated at approximately 630 nm. The dark delay time between exposure ...