Optical nonlinearity of fullerene-doped polymer nanocomposites

The mechanism of optical nonlinearity of new polymer composites based on a conducting polymer (poly(9-vinylcarbazole) and fullerenes C₇₀ and C₆₀ is studied both experimentally and theoretically. The nonlinear-optical studies of self-action and coupling of two 633-nm beams from a helium-neon laser are performed, and variations in the absorption spectra of the composites illuminated by a laser beam are investigated. It is shown that a 'giant' inertial nonlinearity of organic materials is caused by the difference in polarisabilities of fullerene molecules and their anion radicals, which are formed upon absorption of photons and charge transfer by poly(9-vinylcarbazole) molecules.