At a temperature lower than the melting point of pure pentyl-cyanobiphenyl liquid crystal (5CB) we studied the photorefractive effect of 5CB heavily doped with fullerene (C_60) and obtained a diffraction efficiency of the photorefractive grating of more than 40%, which is more than twice as high as the best data reported to our knowledge. A quasi-permanent grating was observed with a diffraction efficiency of 11.2% after the grating was kept in the dark for a month.
© 2005 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(160.3710) Materials : Liquid crystals
(160.5320) Materials : Photorefractive materials
(190.5330) Nonlinear optics : Photorefractive optics
Yanbo Pei, Fengfeng Yao, Chunfeng Hou, Xiudong Sun, and Zhongxiang Zhou, "High diffraction efficiency and a quasi-permanent grating in photorefractive nematic liquid crystal at low temperature," Opt. Lett. 30, 631-633 (2005)