Theory of Nonlinear Photoconductive Sampling in Atomic Gases

Abstract

AbstractThe formation and evolution of electron wave packets in the process of strong‐field ionization is one of the major research topics in attosecond science. The recently developed technique of nonlinear photoconductive sampling (NPS) requires a detailed understanding of these dynamics and provides a new approach to studying them. This work is motivated by the lack of a solid theoretical foundation for NPS measurements. The analysis shows that, for NPS in atomic gases, the strong‐field approximation provides an adequate description of the ionization dynamics but makes a significant error in predicting the spectral response function because the Coulomb interaction between photoelectrons and their parent ions significantly affects the motion of the electron wave packets.