Spectral dispersion of ultrafast optical limiting in reduced graphene oxide

Abstract

We report the spectral dispersion of ultrafast optical limiting in reduced graphene oxide (rGO) sheets, measured by the white light continuum (WLC) Z-scan technique, for 100 fs laser pulses. rGO, synthesized by modified Hummers method followed by hydrothermal reduction, is found to exhibit excellent optical limiting for the entire wavelength regime investigated (400 nm-700 nm). This is due to its increased crystalline nature and extended π conjugation. Results show good agreement with those measured by traditional monochromatic Z-scans at multiple wavelengths. In comparison, the WLC Z-scan is a single measurement which is much faster and has good wavelength resolution.