Observation of intense second harmonic generation from MoS2atomic crystals

Abstract
The nonlinear optical properties of few-layer MoS2 two-dimensional crystals are studied using femtosecond laser pulses. We observed highly efficient second-harmonic generation from the odd-layer crystals, which shows a polarization intensity dependence that directly reveals the underlying symmetry and orientation of the crystal. Additionally, the measured second-order susceptibility spectra provide information about the electronic structure of the material. Our results open up opportunities for studying the nonlinear optical properties in these two-dimensional crystals. DOI: http://dx.doi.org/10.1103/PhysRevB.87.201401 ©2013 American Physical Society