Wavelength scaling of the cutoff energy in the solid high harmonic generation

Abstract

The wavelength scaling of the cutoff energy in solid high harmonic generation (HHG) is investigated theoretically by separating the contributions into the intraband and interband components. We find that, the cutoff energies of intraband and interband HHG exhibit the essentially different wavelength dependences. Specifically, the cutoff energy of the intraband HHG is wavelength independent, whereas the cutoff energy of the interband HHG depends linearly on the laser wavelength. Our results can uniformly interpret two current different wavelength scalings of the cutoff energy reported in previous researches. The fundamentally different wavelength scalings of the cutoff energy for intraband and interband HHG can be used to distinguish the two mechanisms.