Broadband and comparative third-order nonlinearities in reduced graphene oxide with CVD graphene

Abstract We successfully fabricated 2D thin film by dispersing reduced graphene oxide into the PVA matrix and experimentally determined the third-order nonlinearity of reduced graphene oxide in the visible region of the spectrum (450–750 nm) by the combination of spectroscopic ellipsometry and femtosecond pump and probe spectroscopy. The utilization of chemical vapor deposition (CVD) graphene increases in nanophotonics technologies owing to the high tunability superior to noble metals. However, their scalable application is limited due to high-temperature, high-cost fabrication techniques, and complicated transfer procedures. Here, reduced graphene oxide is proposed to be a promising nominee, with relatively simple and low-cost fabrication techniques. Comparable nonlinearity to that of CVD graphene, and identical tunability that π conjugation electronic transitions dominates their nonlinear response, demonstrated that reduced graphene oxide is a viable alternative. The third-order susceptibility in the visible region reveals their substantial behavior to wavelength and pulse width of light in nonlinear state, which propels the movement of manipulating light at the nanoscale over broad wavelength.