High Interharmonic Generation from Isolated Bound States

Abstract

High harmonic generation (HHG) is a nonlinear process in which systems driven by an intense laser emit integer harmonics of the driving field. Here we report that the strong nonlinear response of systems with isolated bound states split the HHG spectrum into nonharmonic Mollow-type triplets that reveal the internal electronic dynamics. We identify the conditions required to observe these phenomena and propose potential experimental systems that could enable their detection. Our findings offer new insights into the fundamental physics of HHG and may have applications in high-harmonic spectroscopy, X-ray physics, and the study of ultrafast dynamics.