Measuring third-order susceptibility tensor elements of monolayer MoS2 using the optical Kerr effect method

We present a femtosecond optical heterodyne detection of the optical Kerr effect study on Chemical Vapor Deposition-grown monolayer MoS2 films at 800 nm. The third-order nonlinear optical susceptibility (i.e., χ xxyy ( 3 )+ χ xyyx ( 3 )) of monolayer MoS2 is determined to be 1.4 × 10−9 esu, and the ultrafast temporal response process indicates that the susceptibility origins from nonresonant electronic polarization. Based on Kleinman symmetry, susceptibility tensor elements are determined, and further, the nonlinear refractive indexes of any elliptically polarized light could be calculated for MoS2. These results will benefit the application of MoS2 in nonlinear photonic devices.