Comparison of Coulomb-Laser-Coupling and Continuum-Continuum delays for infrared wavelengths between 700nm - 8000nm

The measurement of attosecond photoionization delays can be used to study electron dynamics in atomic and molecular systems. Over the past two decades, two key methods have emerged for experimentally extracting such delays. These are known as streaking, where an electron is ionized by a single attosecond extreme-ultraviolet (XUV) pulse while being dressed by a few-cycle infrared probe pulse, and Reconstruction of Attosecond Beating By Two-photon Transitions (RABBITT), which exploits the interference between different ionization pathways by using an XUV attosecond pulse train overlapped with a long duration (typically >30 fs) infrared laser pulse. Because both methods require the use of an infrared laser field, the overall time delay is often treated as the sum of a Wigner time delay (related to the specifics of the ionization target) and an additional delay due to the photoelectron interacting with the infrared field. In streaking, this additional correction is called the Coulomb-Laser-Coupling (CLC) delay, while in RABBITT it is called the Continuum-Continuum (CC) delay. Numerous theoretical models have been proposed to accurately explain how the CLC and CC time delay changes with respect to photoelectron kinetic energy; however, systematic comparisons between the various theories have only been performed for wavelengths close to 800 nm. In this study, we illustrate through various analytical and numerical results how two CLC and CC formulae are equivalent for nearly all infrared wavelengths and photoelectron energies. However, in general, we find that CLC and CC delays can only be approximated as equivalent for certain wavelengths and kinetic energies.