Diffraction from Polarization Holographic Gratings with Surface Relief in Side-chain Azobenzene Polyesters

Polarization holographic gratings in side-chain azobenzene polyesters with linear and circular photoanisotropy.

We investigate thin phase polarization holographic gratings recorded with two waves with orthogonal linear polarizations in materials in which illumination with linearly/circularly polarized light gives rise to linear/circular birefringence. The theoretical analysis shows that the presence of circular photoanisot-ropy changes significantly the diffraction characteristics of the gratings. The in...

Azobenzene Side-Chain Liquid Crystalline Polyesters with Outstanding Optical Storage Properties

A flexible azobenzene side-chain liquid crystalline (SCLC) polyester architecture employed for reversible optical storage is described. The modular design allows four structural parameters to be individually modified. These parameters: ithe methylene side-chain spacer length, iithe substituent on azobenzene, iiithe methylene main-chain segment length, and ivthe polyester molecular mass, all inf...

Self - organizing photorefractive neural network

The three dimensional display of images of moving objects has been a dream for many decades. Ranging from a study of microscopic objects, such as cells, in their natural environment to three dimensional movies, this dream has been realized under certain circumstances. Short recordings of moving objects have been made holo-graphically in silver halide films. But apart from limited sensitivity, t...

High diffraction efficiency polarization gratings recorded by biphotonic holography in an azobenzene liquid crystalline polyester

Surface-relief and polarization gratings for solar concentrators.

Transmission gratings that combine a large diffraction angle with a high diffraction efficiency and a low angular and wavelength dispersion could be used to collect sunlight in a light guide. In this paper we compare the diffractive properties of polarization gratings and classical surface-relief gratings and explore their possible use in solar concentrators. It is found that polarization grati...