Dispersion of the resonant second order nonlinearity in 2D semiconductors probed by femtosecond continuum pulses
Date of Original Version
We demonstrate an effective microspectroscopy technique by tracing the dispersion of second order nonlinear susceptibility (χ(2)) in a monolayer tungsten diselenide (WSe2). The χ(2) dispersion obtained with better than 3 meV photon energy resolution showed peak value being within 6.3-8.4×10-19 m2/V range. We estimate the fundamental bandgap to be at 2.2 eV. Sub-structure in the χ(2) dispersion reveals a contribution to the nonlinearity due to exciton transitions with exciton binding energy estimated to be at 0.7 eV.
Mokim, Mohammad, Adam Card, Bindeshwar Sah, and Feruz Ganikhanov. "Dispersion of the resonant second order nonlinearity in 2D semiconductors probed by femtosecond continuum pulses." AIP Advances 7, 10 (2017). doi:10.1063/1.5006794.