Third-order nonlinear optical response of CH_3NH_3PbI_3 perovskite in the mid-infrared regime

The third-order nonlinear optical properties of CH3NH3PbI3 perovskite film have been investigated by the Z-scan technique in the mid-infrared (mid-IR) region. We prepared the high-quality CH3NH3PbI3 films with the precursor solutions, and experimentally observed its broadband saturable absorption behavior and large Kerr nonlinearity. The CH3NH3PbI3 perovskite film exhibited a large nonlinear refractive index (~10−12 m2/W) in the mid-IR regime. Our study indicates the great potential of the organic-inorganic perovskite material in the mid-IR nonlinear optics, and might provide some new sights for Kerr nonlinearity based mid-IR nonlinear optical application.