Since de discovery of graphene, the family of 2-dimensional materials has attracted much recent attention. In this work, 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 new opportunities for studying the non-linear optical properties in these novel 2D crystals.
@article{arxiv.1304.4289,
title = {Observation of Intense Second Harmonic Generation from MoS$_{2}$ Atomic Crystals},
author = {Leandro M. Malard and Thonimar V. Alencar and Ana Paula M. Barboza and Kin Fai Mak and Ana M. de Paula},
journal= {arXiv preprint arXiv:1304.4289},
year = {2013}
}