Accessing properties of electron wave packets generated by attosecond pulse trains through time-dependent calculations
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States)
We present a time-dependent method for calculating the energy-dependent atomic dipole phase that an electron acquires when it is ionized by the absorption of a single ultraviolet photon. Our approach exactly mirrors the method used to experimentally characterize a train of attosecond pulses. In both methods the total electron phase is measured (calculated) via a two-photon interference involving the absorption or emission of an additional infrared photon in the continuum. In our calculation we use a perfect (zero spectral phase) light field and so extract the atomic dipole phase directly from the electron wave packet. We calculate the atomic phase for argon, neon, and helium at low infrared intensities and compare them to previous perturbative calculations. At moderate infrared probe intensities, we find that that the dipole phase can still be reliably determined using two-photon interference, even when higher-order processes are non-negligible. We also show that a continuum structure, in this case a Cooper minimum in argon, significantly affects the probability for infrared absorption and emission over a range of energies around the minimum, even at low infrared intensities. We conclude that well-characterized attosecond pulse trains can be used to examine continuum structures in atoms and molecules.
- OSTI ID:
- 20718382
- Journal Information:
- Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electron choreography at the attosecond time scale
Related Subjects
ABSORPTION
ARGON
ATOMS
COMPARATIVE EVALUATIONS
DIPOLES
ELECTRONS
ENERGY DEPENDENCE
HARMONIC GENERATION
HELIUM
INFRARED SPECTRA
INTERFERENCE
IONIZATION
MOLECULES
NEON
PHOTON EMISSION
PHOTONS
PROBABILITY
PULSES
TIME DEPENDENCE
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
WAVE PACKETS