Ic. Khoo et al., Dye-doped photorefractive liquid crystals for dynamic and storage holographic grating formation and spatial light modulation, P IEEE, 87(11), 1999, pp. 1897-1911
The basic mechanisms of photo-induced space charge field formation, directo
r axis I e-orientation, and refractive index changes in fullerene C60- and
dye-doped nematic liquid crystals films are presented. In particular, in al
igned methyl-red-doped nematic liquid crystal film, we observe a nonlinear
index change coefficient as high as 10 cm2(/)W, associated with purely opti
cally induced liquid crystal director axis re-orientation. Experimental obs
ervations of dynamic and high-resolution storage holographic grating format
ion, two beam coupling with gain of nearly 3000 cm(-1), optical limiting ac
tion at nanowatt cw laser power, and incoherent-coherent image conversion a
t mu W/cm(2) light intensity level are discussed.