Asymmetries in Above-Threshold Ionization

Abstract

Above-threshold atomic photoemission by intense elliptically polarized light is not symmetric with respect to reflection about either principal polarization axis, contrary to predictions. Simultaneous reflection about both axes is symmetric. These asymmetries occur in helium, krypton, and xenon photoelectron spectra, and depend on the laser intensity and polarization, and the electron energy. Possible mechanisms are discussed.