Photorefractive potential applications

Potential applications of photorefractive materials are manifold. To date, demonstrated effects include real time holography, correlation filtering, and various "novelty filter applications, one of which is the development of a microscope which distinguishes moving objects (such as living cells) from a stationary background.(149) The latter application employed BaTiC>3 as the active material. 

Photorefractive materials have attracted considerable interest because of their potential applications in electro-optic devices, e.g., for holograms, optical computing, or as storage media for erasable read-write optical memories. As their name implies, photorefractive materials are photosensitive and have an electric field-dependent refractive index. 

The polymers derived from ruthenium(II)-polypyridine complexes have demonstrated promising potential for application in solar energy conversion, sensors, polymer-supported electrodes, nonlinear optics, photorefraction, and electroluminescence [27-32]. 

Linkage isomerizations have also been observed for other small molecules such as N2, N02, NCS, S02, and dimethylsulfoxide (DMSO).15 The isomers are likely participants as intermediates in biorelevant ligand interchange or addition processes, in the NO recombination after photolysis, or even in the route to NO release from the ES in aqueous, room-temperature photochemistry (Section 7.7). Indeed, the photo-switchable nitrosyl compounds are an attractive class of materials with favorable photochromic and photorefractive properties, potentially useful for optical and biomedical applications. 

Two beam coupling measurements can be complicated by the presence of beam fanning, by which additional coupling to randomly scattered light in the sample leads to loss of energy to the scattered light (178). Though not a measurement technique, it is a potentially important application of photorefractive polymers and is discussed further in Applications section. 

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