Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive material...Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive materials due to the existence of a direct band gap in the monolayer limit that can be used to enhance nonlinear optical phenomena, such as Raman spectroscopy. Here, we have investigated four-wave mixing processes in bulk MoS_2 using a multiplex coherent anti-Stokes Raman spectroscopy setup. The observed four-wave mixing signal has a resonance at approximately 680 nm, corresponding to the energy of the A excitonic transition of MoS_2. This resonance can be attributed to the increased third-order nonlinear susceptibility at wavelengths near the excitonic transition. This phenomenon could open the path to using MoS_2 as a substrate for enhancing four-wave mixing processes such as coherent anti-Stokes Raman spectroscopy.展开更多
基金National Science Foundation(NSF)(CHE-1609608)Welch Foundation(A-1261,AA-1956-20180324,A-1547)+1 种基金Baylor University(Baylor)Office of Naval Research(ONR)(N00014-16-1-2578)
文摘Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive materials due to the existence of a direct band gap in the monolayer limit that can be used to enhance nonlinear optical phenomena, such as Raman spectroscopy. Here, we have investigated four-wave mixing processes in bulk MoS_2 using a multiplex coherent anti-Stokes Raman spectroscopy setup. The observed four-wave mixing signal has a resonance at approximately 680 nm, corresponding to the energy of the A excitonic transition of MoS_2. This resonance can be attributed to the increased third-order nonlinear susceptibility at wavelengths near the excitonic transition. This phenomenon could open the path to using MoS_2 as a substrate for enhancing four-wave mixing processes such as coherent anti-Stokes Raman spectroscopy.
