Photorefractive Bragg diffraction in high- and low-molar-mass liquid crystal mixtures

Orientational photorefractive Bragg diffraction is observed in high- and low-molar-mass liquid crystal mixtures doped with fullerene (C-60). These novel materials are in a nematic phase without phase separating. In the functionalized materials, we observe a high two-beam coupling gain coefficient (Gamma = 75 cm(-1)) with a low applied field of 4 V/mu m, low total losses (32 cm(-1) including scattering, reflection, and absorption), a high diffraction efficiency (9%), and response time of 200 ms. (C) 1998 American Institute of Physics.