Extreme Nonlinear Optics and Nonequilibrium Dynamics in 3D and 2D Solids

Semiconductor crystal structures, when exposed to intense ultrashort optical or THz pulses, are driven into highly nonequilibrium states that are dominated by higher order many-body carrier correlations. In this talk, I will combine a description of the theoretical foundation of these interactions with experimental realizations of pulsed optically pumped semiconductor disk lasers (SDLs). Under mode-locked pulsed operation, we observed a record less than 100fs pulse duration and demonstrated a novel offset-free tunable mid-IR frequency comb. Recent experiments and simulation have demonstrated co-mode-locked double V-cavities with individual pulse trains sharing a common gain medium while operating at different wavelengths. The microscopic description of both resonant (gain/absorption) interactions and highly detuned THz pulse driven nonperturbative HHG is governed by the microscopic Semiconductor Bloch equations. The second part of my talk will address the theory of quasi-2D Transition Metal Dichalcogenides (TMDCs). Because of the very large in-plane 2D Coulomb potential, these materials display prominent room temperature exciton features below the bandgap – in stark contrast to 3D confinement where the latter are only observed at cryogenic temperatures. Out of plane interactions with other materials are governed by much weaker Van der Waal’s interactions, making them ideal candidates for sensing and electronic communications. The physics of these materials is captured by the Semiconductor Dirac Bloch equations – in contrast to 3D, higher order interactions such as Auger process and pair correlations all appear at the linear ground state level.