Synthesis and characterization of organic photorefractive glass

Bifunctional molecule, which possesses photoconductive and electrooptic properties in one molecule, was synthesized as a new photorefractive material. Carbazole as a photoconductive moiety was covalently bound to thiophene derivative as an electrooptic chromophore via a flexible alkyl chain. The sample prepared from the mixture of bifunctional molecule (89 wt.%), 2,4,7-trinitro-9-fluorenone (1 wt.%) and ethylcarbazole (10 wt.%) showed good photorefractive property. The 50 μm thick film showed the maximum diffraction efficiency of 65% at 70 V/μm, corresponding to a refractive index modulation (Δn) of ca. 4.5×10−3.