ABSTRACT
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 intensities of the waves diffracted in the +1 and -1 orders of diffraction and their ratio depend substantially on the reconstructing-wave polarization. Experiments with films of side-chain liquid-crystalline azobenzene polyester that is a photoanisotropic material of the considered type confirm the unusual polarization properties. It is shown that polarization holography may be used for real-time simultaneous measurement of photoinduced linear and circular birefringence.
ABSTRACT
We report erasable holographic recording with a resolution of at least 2500 lines/mm on unoriented films of sidechain liquid-crystalline polyesters. Recording energies of approximately 1 J/cm(2) have been used. We have obtained a diffraction efficiency of approximately 30% with polarization recording of holograms. The holograms can be erased by heating them to approximately 80 degrees C for approximately 2 min and are available for rerecording.
