High-performance photorefractive materials based on the layered photoconductive polymers PPT-CZ [rigid backbone of poly(<i>p</i>-phenyleneterephthalate) with pendent carbazole groups] are studied. The composites are composed of PPT-CZ and are doped with the sensitizer C<sub>60</sub> and nonlinear optical chromophores. Despite the absence of a plasticizer and the lower concentration of the carbazole photoconductive moieties as compared with poly(<i>N</i>-vinyl carbazole), these materials show high photorefractive sensitivity, i.e., S<sub>n2</sub> of 70± 7 cm<sup>2</sup>/kJ at E<sub>0</sub>=100 V/μm for PPT-CZ(n=12):diethylaminodicyanostyrene:C<sub>60</sub>. The low glass transition temperature (<0°C) leads to a high rotational mobility of the chromophores that results in large refractive-index changes. For all the composites that were investigated, the two-wave mixing gain Γ exceeds 100 cm<sup>−1</sup> at an applied field of 50 V/μm.
© 2003 Optical Society of America
O-Pil Kwon, Suck-Hyun Lee, Germano Montemezzani, and Peter Günter, "Highly efficient photorefractive composites based on layered photoconductive polymers," J. Opt. Soc. Am. B 20, 2307-2312 (2003)