POLARIZATION HOLOGRAPHIC GRATINGS IN SIDE-CHAIN AZOBENZENE POLYESTERSWITH LINEAR AND CIRCULAR PHOTOANISOTROPY

We investigate thin phase polarization holographic gratings recorded w ith two waves with orthogonal linear polarizations in materials in whi ch illumination with linearly/circularly polarized light gives rise to linear/circular birefringence. The theoretical analysis shows that th e presence of circular photoanisotropy changes significantly the diffr action characteristics of the gratings. The intensities of the waves d iffracted in the +1 and -1 orders of diffraction and their ratio depen d substantially on the reconstructing-wave polarization. Experiments w ith films of side-chain liquid-crystalline azobenzene polyester that i s a photoanisotropic material of the considered type confirm the unusu al polarization properties. It is shown that polarization holography m ay be used for real-time simultaneous measurement of photoinduced line ar and circular birefringence. (C) 1996 Optical Society of America