High-performance photorefractivity in high- and low-molar-mass liquid crystal mixtures

High-performance photorefractivity in a thick-grating regime was observed in high- (H-LC) and low-molar-mass liquid crystal (L-LC) mixtures (HL-LCMs) doped with fullerene. The photorefractive performance strongly depended on the concentration ratio of H-LC and L-LC. A high net gain coefficient over 600 cm(-1) was achieved with low applied dc fields (0.7 V/mu m) and a fringe spacing of 2.8 mm. The gain coefficients and the resolution increased with increasing the concentration of the H-LCs. The photorefractive grating formation time was varied between 0.12 and 3.5 s, which depended on the concentration of the H-LCs. (C) 1999 American Institute of Physics. [S0021-8979(99)02005-8].