REVERSIBLE STORAGE OF LIGHT-INDUCED GRATINGS IN LOW MOLAR-MASS LIQUID-CRYSTALS

Low molar mass liquid crystals which exhibit an anisotropic glassy state are investigated for erasable recording processes. Optical gratings were written with intensities less than 1000W/cm(2) obtained from an argon-ion laser and read out by diffraction of a weak He-Ne laser. Grating build-up times of less than 5 ms have been observed. Diffraction efficiencies of several percents were measured as a function of intensity and grating periods down to 5 mu m. The stored gratings are erased by homogeneous laser heating. It is shown that the observed recording phenomena is connected with optical heating and light-induced transitions from the glassy to the liquid crystalline state of the material.