▎ 摘　　要

We present a detailed theoretical analysis of reverse saturable absorption (RSA) in graphene with picosecond laser pulses at 532 nm, and in graphene-oxide (GO)-metal porphyrin composites with femtosecond (fs) laser pulses at 800 nm. Increase in pulse intensity leads to increased contrast in graphene due to strong two-photon absorption (TPA) and larger excited-state absorption coefficients in comparison to GO and GO-metal porphyrin composite materials. The RSA characteristics are sensitive to pump pulse intensity and pulse width, TPA coefficient and concentration and have been theoretically optimized to design all-optical NOT and the universal NOR and NAND logic gates. Femtosecond operation at relatively lower pump intensities (GW/cm compared to Cu-Pc doped PMMA thin films (TW/cm and GO thin films (GW/cm demonstrates the applicability of GO-metal porphyrin composites for ultrafast all-optical information processing.