uri physics colloquium

Second Harmonic generation Microspectroscopy of 2D Semiconductors with femtosecond continuum pulses.

Feruz Ganikhanov Ph.D.

Department of Physics ,University of Rhode Island

Abstract

We demonstrate an effective second harmonic generation spectroscopy technique using broadband femtosecond continuum pulses. Dispersion of the second order nonlinear susceptibility (χ⁽²⁾) was traced in a monolayer tungsten diselenide (WSe₂) with 2 meV spectral resolution. The peak χ⁽²⁾ values are found to be within 89-104 pm/V range. Sub-structure in the χ⁽²⁾ dispersion reveals a contribution to the nonlinearity due to exciton transitions with a binding energy of 0.72 eV.

Second part of the talk will cover results on dephasing of vibrational modes in mouse fat tissue.