Two-Color Quantum Light for Strong-Field Physics

Abstract

High-harmonic generation (HHG) is a highly nonlinear process that enables the conversion of strong low-frequency driving fields in to high-frequency radiation.While conventionally driven by classical laser fields,the quantum properties of the driving field provide new possibilities for control ling the photon statistics and correlation soft he generated harmonics. In this work, we investigate HHG driven by bichromatic fields composed of a coherent state and bright squeezed light. By analyzing the photon statistics, we reveal distinct statistical properties of the generated harmonics depending on the quantum nature of the driving field.ForDSV-driven HHG, the emitted harmonics exhibit weakly super-Poissonian statistics, depending on the degree of squeezing and on the polarization configuration of the driving field.Incontrast,BSV-driven HHG leads to strongly enhanced photon correlations. Furthermore, by splitting the BSV field on a beam splitter and recombining the resulting modes with the coherent driver, we demonstrate the generation of entangled harmonic radiation between the two HHG out puts. Our results show that quantum fluctuations and correlations of the driving field can be transfer red to the high-harmonic regime, establishing HH Gasa platform for generating entangled quantum light at extreme frequencies.