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Visar resultat 11 - 15 av 37 avhandlingar som matchar ovanstående sökkriterier.

  1. 11. Towards ultrafast imaging with extreme ultraviolet light sources

    Författare :Jörg Schwenke; Lunds universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photo emission electron microscopy; Focusing of X-ray radiation; Digital holography; High-order harmonic generation; Free-electron laser seeding; Secondary electron cascades; Fysicumarkivet A:2012:Schwenke;

    Sammanfattning : This thesis reports experimental studies performed with two advanced coherent XUV sources with ultrashort pulse duration, high-order harmonic generation and seeded-free electron laser. High-order harmonic generation (HHG) is the generation of overtones of a fundamental laser pulse in a medium, e.g. noble gases. LÄS MER

  3. 12. Spatial and temporal metrology of intense attosecond pulses

    Författare :Helene Coudert-Alteirac; Atomfysik; []
    Nyckelord :Ultrafast optics; High-order harmonic generation; Filamentation; Attosecond; Femtosecond; Extreme ultraviolet; Wavefront measurement; Optical metrology; XUV optics; interferometry; Pump-probe; Fysicumarkivet A:2018:Coudert-Alteirac;

    Sammanfattning : Attosecond pulses are short enough to capture the electronic dynamics in atoms and molecules. The work presented in this thesis deals with the generation and optimization of attosecond extreme-ultraviolet (XUV) pulses. LÄS MER

  4. 13. Sub-Cycle Control of Strong-Field Processes on the Attosecond Timescale

    Författare :Stefanos Carlström; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-order harmonic generation; Quantum path interference; Coherence; Fysicumarkivet A:2017:Carlström;

    Sammanfattning : This PhD thesis deals with the sub-cycle nature of ultrafast phenomena that occur in strong-field light–matter interactions. As it is of interest to control these phenomena, we must understand them in order to manipulate them. The tools at our disposal are intense laser pulses of short duration, and the systems we study are atoms. LÄS MER

  5. 14. Time-Frequency Analysis in Attosecond Spectroscopy

    Författare :Marcus Isinger; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond; Spectroscopy; Time-Frequency; High-order harmonic generation; Rabitt; Interferometry;

    Sammanfattning : This thesis deals with ultrafast dynamics of electronic processes in rare gas atoms. The processes we explore include photoemission, where we time the emission of electrons moving away from the atomic core following ionization by a photon; and auto-ionization, where the atom spontaneously releases an electron wave-packet following photo-excitation. LÄS MER

  7. 15. Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources

    Författare :Jan Lahl; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Covariance; Ultrafast; High-order harmonic generation; Extreme Ultraviolet; Pump probe; FLASH; Velocity map imaging; wavefront; FEL; photodissociation; Coulomb explosion; Fysicumarkivet A:2019:Lahl;

    Sammanfattning : The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. LÄS MER