Ultrafast all-optical universal logic gates with graphene and graphene-oxide metal porphyrin composites

Abstract

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$$^{2})$$2) compared to Cu-Pc doped PMMA thin films (TW/cm$$^{2})$$2) and GO thin films (GW/cm$$^{2})$$2) demonstrates the applicability of GO-metal porphyrin composites for ultrafast all-optical information processing.