Attosecond Streaking Time Delays

We review theoretical studies of the attosecond streaking time delay concept in photoionization via the investigation of the electron dynamics in the streaking field after the transition of the photoelectron into the continuum upon absorption of an extreme ultraviolet photon. The finite-range interpretation, introduced by us, highlights that the delay is accumulated until the streaking pulse ends over a finite range of the potential of the parent ion. We also summarize a few applications which provide insights into different aspects of the streaking time delay concept.

C. Goldsmith et al., Applied Sciences 9, 492 (2019).

Attosecond Spectroscopy

In the brief review we first present the concepts and physical understanding behind the generation of attosecond optical pulses via the highly nonlinear optical high harmonic generation process driven by strong laser pulses. In the second part a number of spectroscopic techniques and applications for the temporal resolution on the attosecond timescale are discussed.

A. Jaron-Becker and A. Becker, in Encyclopedia of Modern Optics (2nd Edition), ed. b R. Guenther and D. Steel (Oxford: Elsevier, 2018) pp. 233-243

Laser Driven Nonadiabatic Electron Dynamics

In two reviews, we summarize more than a decade of experimental and theoretical investigations regarding the nonadiabatic electron response to intense femtosecond duration laser fields in a variety of molecular systems. The reviews include an overview of observed signatures of nonadiabatic electron dynamics in the ionization and fragmentation patterns of large and highly conjugated molecules as well as related theoretical models. We further discuss theoretical results regarding the analysis of the mechanisms for nonadiabaticity in the simplest molecular system, the hydrogen molecular ion. Finally, the impact of the laser-induced nonadiabatic electron dynamics on a variety of observables is discussed.

M.R. Miller et al., Optica 3, 259-269 (2016)
A. Becker et al., in Attosecond Physics: Attosecond Measurements and Control of Physical Systems, Springer Series in Optical Sciences, Vol. 177 (Springer, Berlin - Heidelberg, 2013) p. 207-229

Intense-Field Many-Body S-Matrix Theory

We review a systematic ab-initio approach to investigate the dynamics of atoms and molecules interacting with intense laser radiation. The IMST is a general S-matrix scheme, which provides the option to account simultaneously of different reference Hamiltonians in the initial, intermediate and final states. It provides an effective method for analyses of direct and rearrangement processes that can occur in the presence of intense laser fields, in which the internal Coulomb interaction between the charged particles in the atom or molecule and the external laser-electron interaction energy are of comparable strength.

A. Becker and F.H.M. Faisal, J. Phys. B 38, R1 (2005)