▎ 摘　　要

Non linear optical properties of few grapheme layers were examined by Z-scan technique. We had prepared thin graphene layers by the exfoliation method. Then, we used an atomic force microscope (AFM) to verify that our prepared samples contain only very few layers. Finally, the study of linear optical properties allowed us to deduce that the graphene is completely transparent. Whereas, the study of its non linear optical properties showed that its Kerr refractive index is about 10(-7) cm W-1.