Intracycle and Intercycle Interferences in Above-Threshold Ionization: the Time Grating

TL;DR

This paper explores the complex interference patterns in above-threshold ionization using a semiclassical model, revealing how intracycle and intercycle interferences create a time-domain diffraction grating effect observable in ATI spectra.

Contribution

It introduces a semiclassical framework to analyze the interplay of intracycle and intercycle interferences in ATI, linking spectral modulations to a time grating concept.

Findings

Interference patterns are modulated by laser wavelength.

Energy shifts are influenced by the Coulomb tail of the atomic potential.

ATI spectra exhibit diffraction-like features in the time domain.

Abstract

Within a semiclassical description of above-threshold ionization (ATI) we identify the interplay between intracycle and intercycle interferences. The former is imprinted as a modulation envelope on the discrete multiphoton peaks formed by the latter. This allows to unravel the complex interference pattern observed for the full solution of the time-dependent Schr\"odinger equation (TDSE) in terms of diffraction at a grating in the time domain. These modulations can be clearly seen in the dependence of the ATI spectra on the laser wavelength. Shifts in energy modulation result from the effect of the long Coulomb tail of the atomic potential.