Reverse saturable absorption and optical limiting performance of fullerene-functionalized polycarbonates in femtoseond time scale

The reverse saturable absorption and the optical limiting (OL) property of fullerene-functionalized polycarbonates (C₆₀-PCs) which were synthesized by a direct reaction of C₆₀ and PC in the presence of AIBN using 1, 1, 2, 2-tetrachloroethane as the solvent under microwave irradiation (MI) was investigated by z-scan technique in femtosecond scale. Its reverse saturable absorption behavior was believed to being caused by the covalently attached fullerene to the polymer chain and was found to be of the same order as C₆₀. The measured OL results revealed that the absorption cross-section of the photo-excited singlet state was larger than that of the ground state, and the ratio of the absorption cross-section of the photo-excited singlet state to that of the ground state was determined by fitting the experimental data to the numerical integration by using the rate equation treatment. These new synthesized materials which are soluble in common organic solvents can be considered as potential sources for further optical applications, especially in ultrashort scale.