Storage of erasable laser induced holographic gratings in low molar mass cholesteric liquid crystals

Abstract
We succeeded in storing optical information with low-molecular-weight cholesteric liquid crystals. Nematic mixtures of glassy compounds which are chiralized by the addition of small amounts CB15 (BDH) have been used. Reversible optically induced holographic gratings were stored both below the glass transition temperature and above the glass transition in the temperature region of high viscosity. Erasure can be achieved by local heating of the sample making possible to use the material for multiple storage processes. A mechanism to explain the formation of the grating is discussed.