| 1. |
- Vuong, L. T., et al.
(författare)
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Optimal pulse compression via sequential filamentation
- 2007
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Ingår i: Quantum Electronics and Laser Science Conference, QELS 2007. - 1557528349 - 9781557528346
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Konferensbidrag (refereegranskat)abstract
- We demonstrate theoretically and experimentally a robust method based on sequential filamentation to optimize compression of high-energy pulses in gases. We gain insight into this process by comparing compression dynamics for linear- and circularly-polarized pulses.
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| 2. |
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Zaïr, A., et al.
(författare)
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Confinement of attosecond train pulses by using a modulated polarization IR pulse
- 2005
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Ingår i: 2005 Conference on Lasers and Electro-Optics Europe. - 0780389743 - 9780780389748
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Konferensbidrag (refereegranskat)abstract
- We study the temporal and spectral behaviour of high order harmonics generated by pulses with temporally modulated polarization. We observe a harmonic temporal confinement and a harmonic spectral broadening, compatible with 1 -or-2 attosecond pulse emission.
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| 7. |
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| 8. |
- Carré, B., et al.
(författare)
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Characterization of attosecond pulse trains
- 2007
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Ingår i: Ultrafast Optics V. - New York, NY : Springer New York. - 1556-1534 .- 0342-4111. - 9780387491172 ; 132, s. 45-56
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Konferensbidrag (refereegranskat)abstract
- Ultrashort light pulses, as short as 100 as, can be produced from high harmonic generation (HHG) in an atomic gas medium. This major achievement of the last 6 years in high field physics has now been demonstrated in different conditions of medium-field interaction [1].
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| 9. |
- Hauri, C. P., et al.
(författare)
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Attosecond pulse trains generated in a filament
- 2006
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Ingår i: Quantum Electronics and Laser Science Conference, QELS 2006. - 1557528136 - 9781557528131
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Konferensbidrag (refereegranskat)abstract
- We present temporal characterization of attosecond pulse trains generated during selfguided propagation of intense pulses in a long gas target. Spectral phase jumps are observed, affecting the temporal shape of the attosecond pulse train.
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| 10. |
- Hauri, C. P., et al.
(författare)
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Self-compression of ultrashort pulses in filaments
- 2006
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Ingår i: Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006. - 1557528136 - 9781557528131
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Konferensbidrag (refereegranskat)abstract
- We report the self-compression of linearly and circularly polarized light pulses down to the few-cycle regime by self-guided beam propagation of intense 38-fs pulses in different gases with uniform density and with a pressure gradient.
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| 11. |
- Kelkensberg, F., et al.
(författare)
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Molecular Dissociative Ionization and Wave-Packet Dynamics Studied Using Two-Color XUV and IR Pump-Probe Spectroscopy
- 2009
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Ingår i: Physical Review Letters. - 1079-7114. ; 103:12
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined theoretical and experimental study of ultrafast wave-packet dynamics in the dissociative ionization of H-2 molecules as a result of irradiation with an extreme-ultraviolet (XUV) pulse followed by an infrared (IR) pulse. In experiments where the duration of both the XUV and IR pulses are shorter than the vibrational period of H-2+, dephasing and rephasing of the vibrational wave packet that is formed in H-2+ upon ionization of the neutral molecule by the XUV pulse is observed. In experiments where the duration of the IR pulse exceeds the vibrational period of H-2+ (15 fs), a pronounced dependence of the H+ kinetic energy distribution on XUV-IR delay is observed that can be explained in terms of the adiabatic propagation of the H-2+ wave packet on field-dressed potential energy curves.
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| 12. |
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| 13. |
- L'Huillier, A., et al.
(författare)
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Atomic physics with attosecond pulses
- 2006
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Ingår i: International Conference on Ultrafast Phenomena, UP 2006. - 1557528101 - 9781557528100
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Konferensbidrag (refereegranskat)
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| 14. |
- Mansten, Erik, et al.
(författare)
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Spectral signature of short attosecond pulse trains.
- 2009
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Ingår i: Physical Review Letters. - 1079-7114. ; 102:8
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Tidskriftsartikel (refereegranskat)abstract
- We report experimental measurements of high-order harmonic spectra generated in Ar using a carrier-envelope-offset (CEO) stabilized 12 fs, 800 nm laser field and a fraction (less than 10%) of its second harmonic. Additional spectral peaks are observed between the harmonic peaks, which are due to interferences between multiple pulses in the train. The position of these peaks varies with the CEO and their number is directly related to the number of pulses in the train. An analytical model, as well as numerical simulations, support our interpretation.
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| 15. |
- Power, E., et al.
(författare)
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Dispersion-free interferometric autocorrelator for measurement of ultra-broadband pulses
- 2006
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Ingår i: Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006. - 1557528136 - 9781557528131
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a dispersion-free split mirror interferometric autocorrelator suitable for measuring pulses with durations from hundreds of attoseconds to tens of femtoseconds and spectral content from the near-UV to near-IR.
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| 16. |
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| 17. |
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| 18. |
- Sansone, G., et al.
(författare)
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Attosecond excitation of electron wavepackets
- 2008
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Ingår i: Quantum Electronics and Laser Science Conference, QELS 2008. - 9781557528599
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Konferensbidrag (refereegranskat)abstract
- We present experiments, supported by time-dependent Schrödinger simulations, on the dynamics of Helium bound states after an attosecond excitation in the presence of a strong infrared laser field.
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| 19. |
- Schwenke, Jörg, et al.
(författare)
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Single-shot holography using high-order harmonics
- 2008
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Ingår i: Journal of Modern Optics. - : Informa UK Limited. - 0950-0340 .- 1362-3044. ; 55:16, s. 2723-2730
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Tidskriftsartikel (refereegranskat)abstract
- This work demonstrates single-shot holography with ultrashort XUV pulses. The pulses are generated by high-harmonic generation in an Ar gas cell and focused to produce a strongly divergent reference beam suitable for in-line holography of micrometer size objects. The achieved intensity of the high-order harmonics in the XUV regime is sufficient for single-shot holography with good signal-to-noise ratio. A numerical algorithm is applied to reconstruct real images from the recorded holograms, which also includes an iterative process to reduce the twin-image blurring. Holograms and reconstructed images of microscope tips are presented and a description of the algorithm is given.
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| 20. |
- Sola, I. J., et al.
(författare)
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Temporal and spectral studies of high-order harmonics generated by polarization-modulated infrared fields
- 2006
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 74:1
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Tidskriftsartikel (refereegranskat)abstract
- The temporal confinement of high harmonic generation (HHG) via modulation of the polarization of the fundamental pulse is studied in both temporal and spectral domains. In the temporal domain, a collinear cross-correlation setup using a 40 fs IR pump for the HHG and a 9 fs IR pulse to probe the generated emission is used to measure the XUV pulse duration. The observed temporal confinement is found to be consistent with theoretical predictions. An increased confinement is observed when a 9 fs pulse is used to generate the harmonics. An important spectral broadening, including a continuum background, is also measured. Theoretical calculations show that with 10 fs driving pulses, either one or two main attosecond pulses are created depending on the value of the carrier envelope phase.
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| 21. |
- Varju, Katalin, et al.
(författare)
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Experimental studies of attosecond pulse trains
- 2005
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Ingår i: Laser Physics. - 1054-660X. ; 15:6, s. 888-898
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Tidskriftsartikel (refereegranskat)abstract
- We present experimental measurements of attosecond pulse trains. The characterization of the pulses uses a spectral interferometry technique that is implemented with a Mach-Zehnder interferometer. This allows us to manipulate independently the pump and probe pulses for a wide range of applications. By letting the attosecond pulses pass through metallic films, we can in particular compensate for the intrinsic chirp of the attosecond pulses corresponding to the plateau spectral region, thus getting pulses as short as 170 attoseconds-only 1.2 optical cycles at the central frequency. The measurement technique is also applicable for determination of the group delay of thin XUV-transparent films and relative delay in the photoionization process. Our experimental method is applied to attosecond pulse trains created by 35- and 9-fs laser pulses, and the shortest train observed consists of three or four pulses.
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| 22. |
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