Boosting solid-state high-harmonic generation efficiency by non-collinear XUV wave mixing with two-color drivers

We present studies on boosting high-harmonic generation (HHG) efficiency from solids in the extreme-ultraviolet (XUV) region by two-color non-collinear wave mixing in silica. Our results show that the conversion efficiency of two-color wave mixing exceeds that of single-color HHG by a factor of at least ten. We analyze the underlying mechanisms, revealing that the synergy between Floquet-Bloch dressing and inter-and intraband dynamics under laser irradiation enables efficient carrier excitation, enhancing harmonic yield. Integrating wave mixing into solid-state HHG could help establish compact, coherent XUV sources for applications where traditional gas-HHG is impractical.