Semiclassical analysis of photoelectron interference in a synthesized two-color laser pulse

Abstract

We measure the photoelectron energy spectra from strong-field ionization of Kr in a two-color laser pulse consisting of a strong 400-nm field and a weak 800-nm field. The intensities of the main above-threshold ionization (ATI) and sideband peaks in the photoelectron energy spectra oscillate roughly oppositely with respect to the relative phase between the two-color components. We study the photoelectron interferometry in strong-field ATI regime from the view of interference of different electron trajectories in order to extend RABBITT type analysis to the strong-field regime. Based on the strong-field approximation model, we obtain analytical expressions for the oscillations of both ATI and sideband peaks with the relative phase. A phase shift of π/4 with respect to the field maximum of the two-color laser pulse is revealed for the interference maximum in the main ATI peak without including the effect of the atomic potential.

Holographic angular streaking of electrons and the Wigner time delay

“…The first step to access the Wigner time delay in strong field ionization within the framework of HASE is to conduct an experiment using a CoRTC field. High ratios of E 390 /E 780 decrease the visibility of the sidebands [10] but also reduce the difference of the minimal and the maximal value of the absolute value of the negative vector potential | A(t )|. As described above, higher values of E 390 /E 780 lead to a more accurate mapping of the offset angle, α, to the phase gradient of the initial momentum distribution after tunneling, φ off .…”

“…The origin of this pattern is a subcycle interference which has been observed experimentally and reproduced using saddlepoint strong field approximation as well as by solving the time-dependent Schrödinger equation [8,9]. Recently, Feng et al [10] have succeeded to model the appearance of sidebands for linearly polarized light by considering semiclassical trajectories that have release times that differ exactly by T 390 which is one cycle of the 2ω field.…”

Angular dependence of the Wigner time delay upon tunnel ionization of H2

“…To meet that challenge, a recently suggested alternative interferometric approach toward Δ τ W,M in momentum space termed “holographic angular streaking of electrons” (HASE) 13 can be used which builds on refs. 25 , 26 . This scheme exploits semi-classical trajectories to model the interference occurring for tunnel ionization 25 , 27 – 29 triggered by a co-rotating two-color (CoRTC) laser field.…”

Low Threshold Optical Bistability in Aperiodic PT-Symmetric Lattices Composited with Fibonacci Sequence Dielectrics and Graphene

“…Aperiodic quasicrystals of Fibonacci multilayer dielectrics have many fascinating optical properties, such as mode beating, strong pulse stretching, and band-edge resonances [55]. The band-edge resonances can localize the electric field [56]. Moreover, the localization of field can be further enhanced by increasing the gain and loss in our PT-symmetric structure [19].…”