Extracting an electron's angle of return from shifted interference patterns in macroscopic high-harmonic spectra of diatomic molecules

摘要

We investigate high-order harmonic spectra from aligned diatomic molecules inintense driving fields whose components have orthogonal polarizations. We focuson how the driving-field ellipticity influences structural interferencepatterns in a macroscopic medium. In a previous publication [Phys. Rev. A 88,023404 (2013)] we have shown that the non-vanishing ellipticity introduces aneffective dynamic shift in the angle for which the two-center interferencemaxima and minima occur, with regard to the existing condition for linearlypolarized fields. In this work we show through simulation that it is stillpossible to observe this shift in harmonic spectra that have undergonemacroscopic propagation, and discuss the parameter range for doing so. Thesefeatures are investigated for $H_2$ in a bichromatic field composed of twoorthogonally polarized waves. The shift is visible both in the near- and in thefar-field regime, so that, in principle, it can be observed in experiments.