Fig. 2
From: Graphene’s nonlinear-optical physics revealed through exponentially growing self-phase modulation
Results of the broadening experiments. a Broadening factor as a function of graphene length for an incoupled peak power of 2.7 W. b Broadening factor as a function of incoupled peak power indicated in blue, magenta, and green for graphene lengths of 220, 660, and 1100 μm, respectively. Both graphs show the experimental data points (with a measurement error below 5 %), the results from our saturable photoexcited-carrier refraction (SPCR) theory (numerical solution from Eqs. (4) and (5), and analytical solution from Eq. (6)), and the results from the theory for conventional self-phase modulation (SPM) using graphene’s strong effective χeff(3) = −10−7 esu as extracted from earlier experiments. c Normalized experimental input spectrum and output spectra for graphene lengths of 660 and 1100 μm excited with an incoupled peak power of 2.7 W. The spectra are normalized to their respective peak power values
