Non-perturbative High Harmonic Generation(HHG) from solids was first reported in ZnO in 2010. Since then HHG has been observed in a number of different crystals, in reflective geometry, from nano-structured solids, and from two dimensional materials.
A related but distinct phenomenon is the generation of high order sideband generation in solids. We will try to better understand the physical mechanisms behind these two processes using experiments and theory