Ghamsari, Behnood G.Tosado, JacobYamamoto, MahitoFuhrer, Michael S.Anlage, Steven M.Partial funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.We have experimentally studied the dispersion of optical conductivity in few-layer graphene through reflection spectroscopy at visible wavelengths. A laser scanning microscope (LSM) with a supercontinuum laser source measured the frequency dependence of the reflectance of exfoliated graphene flakes, including monolayer, bilayer and trilayer graphene, loaded on a Si/SiO2 Fabry-Pérot resonator in the 545–700 nm range. The complex refractive index of few-layer graphene, n − ik, was extracted from the reflectance contrast to the bare substrate. It was found that each few-layer graphene possesses a unique dispersionless optical index. This feature indicates that the optical conductivity does not simply scale with the number of layers, and that inter-layer electrodynamics are significant at visible energies.en-USMeasuring the Complex Optical Conductivity of Graphene by Fabry-Pérot Reflectance SpectroscopyArticle