M. Swoboda - Academia.edu (original) (raw)
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Papers by M. Swoboda
We present experiments on the control over spectral amplitude and phase of attosecond pulses, usi... more We present experiments on the control over spectral amplitude and phase of attosecond pulses, using metallic and semiconductor thin-film dispersive filters. A pulse duration as short as 130 as is obtained.
Physical Review Letters, 2010
We present an interferometric pump-probe technique for the characterization of attosecond electro... more We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultaneously. After a variable delay, the bound WP is ionized by a few-cycle infrared laser precisely synchronized to the original attosecond pulse. By measuring the delay-dependent photoelectron spectrum we obtain an interferogram that contains both quantum beats as well as multi-path interference. Analysis of the interferogram allows us to determine the bound WP components with a spectral resolution much better than the inverse of the attosecond pulse duration.
Physical Review Letters, 2011
We study photoionization of argon atoms excited by attosecond pulses using an interferometric mea... more We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the 3s 2 and from the 3p 6 shell, at different excitation energies ranging from 32 to 42 eV. The determination of single photoemission time delays requires to take into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using an universal formula and is found to account for a substantial fraction of the measured delay.
Physical Review A, 2009
We characterize attosecond pulses in a train using both the well established "reconstruction of a... more We characterize attosecond pulses in a train using both the well established "reconstruction of attosecond beating by interference of two-photon transitions" ͑RABITT͒ technique and the recently demonstrated in situ method, which is based on a weak perturbation of the harmonic generation process by the second harmonic of the laser field. The latter technique determines the characteristics of the single atom emission, while RABITT allows one to measure attosecond pulses "on target." By comparing the results of the two methods, the influence of propagation and filtering on the attosecond pulses can be extracted.
Commercial and Biomedical Applications of Ultrafast Lasers VII, 2007
We analyse recent experiments on momentum shearing interferometry of electron wave packets by usi... more We analyse recent experiments on momentum shearing interferometry of electron wave packets by using an optical analogy with shearing interferometry for optical waves. This analogy offers a convenient point of view to discuss the capabilities and difficulties of this technique used to access the phase of electron wave packets.
We present experiments on the control over spectral amplitude and phase of attosecond pulses, usi... more We present experiments on the control over spectral amplitude and phase of attosecond pulses, using metallic and semiconductor thin-film dispersive filters. A pulse duration as short as 130 as is obtained.
Physical Review Letters, 2010
We present an interferometric pump-probe technique for the characterization of attosecond electro... more We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultaneously. After a variable delay, the bound WP is ionized by a few-cycle infrared laser precisely synchronized to the original attosecond pulse. By measuring the delay-dependent photoelectron spectrum we obtain an interferogram that contains both quantum beats as well as multi-path interference. Analysis of the interferogram allows us to determine the bound WP components with a spectral resolution much better than the inverse of the attosecond pulse duration.
Physical Review Letters, 2011
We study photoionization of argon atoms excited by attosecond pulses using an interferometric mea... more We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the 3s 2 and from the 3p 6 shell, at different excitation energies ranging from 32 to 42 eV. The determination of single photoemission time delays requires to take into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using an universal formula and is found to account for a substantial fraction of the measured delay.
Physical Review A, 2009
We characterize attosecond pulses in a train using both the well established "reconstruction of a... more We characterize attosecond pulses in a train using both the well established "reconstruction of attosecond beating by interference of two-photon transitions" ͑RABITT͒ technique and the recently demonstrated in situ method, which is based on a weak perturbation of the harmonic generation process by the second harmonic of the laser field. The latter technique determines the characteristics of the single atom emission, while RABITT allows one to measure attosecond pulses "on target." By comparing the results of the two methods, the influence of propagation and filtering on the attosecond pulses can be extracted.
Commercial and Biomedical Applications of Ultrafast Lasers VII, 2007
We analyse recent experiments on momentum shearing interferometry of electron wave packets by usi... more We analyse recent experiments on momentum shearing interferometry of electron wave packets by using an optical analogy with shearing interferometry for optical waves. This analogy offers a convenient point of view to discuss the capabilities and difficulties of this technique used to access the phase of electron wave packets.