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Showing result 1 - 5 of 55 swedish dissertations matching the above criteria.

  2. 1. Nonlinear optical techniques for ultrafast laser diagnostics : Development of femtosecond LIF, LIGS, CARS and backward lasing

    Author : Maria Ruchkina; Förbränningsfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; laser diagnostics; femtosecond laser; nonlinear interactions; ultrafast spectroscopy; multi-photon excitation; laser-induced fluorescence; rotational coherent anti-Stokes Raman spectroscopy; laser-induced grating spectroscopy; lasing; backward lasing technique; Fysicumarkivet A:2021:Ruchkina;

    Abstract : The thesis work concerns development and application of four versatile nonlinear optical techniques, based on exploiting ultrashort laser pulses, for diagnostic purposes in gases and flames. The four techniques, all laser-based, are two-photon laser-induced fluorescence (TPLIF), hybrid femtosecond/nanosecond (fs/ns) rotational coherent anti-Stokes Raman scattering (fs/ns RCARS), fs-laser-induced grating spectroscopy (fs-LIGS), and backward lasing. READ MORE

  4. 2. Generation of Ultrashort Pulses – From Femtoseconds to Attoseconds

    Author : Maite Louisy; Atomfysik; []
    Keywords : Attosecond; Femtosecond; Ultrashort laser pulses; Ultrafast optics; High-order harmonic generation; extreme ultraviolet; Post-compression; Hollow-core capillary; d-scan; Optical gating; Fysicumarkivet A:2017:Louisy;

    Abstract : Electronic dynamics takes place on the attosecond timescale and can thus only be studied using a tool with attosecond temporal resolution. High harmonic generation (HHG) provides coherent attosecond pulses in the extreme ultraviolet spectral region. READ MORE

  5. 3. Ionization of large molecules with short laser pulses

    Author : Mikael Kjellberg; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysik; Photoelectron spectroscopy; Momentum mapping imaging; thermal ionization; above threshold ionization; molecular fusion; fullerenes; polyaromatic hydrocarbons; femtosecond-laser.;

    Abstract : The decay dynamics of fullerenes and polyaromatic hydrocarbons (PAH) after femtosecond-laser excitation have been studied experimentally by electron momentum mapping and mass spectrometry. The electron spectra of fullerenes and large PAH-molecules were found to be exponentially decreasing with energy without any distinct peaks outside the photon energy. READ MORE

  6. 4. Ultra-intense laser-plasma interaction for applied and fundamental physics

    Author : Arkady Gonoskov; Mattias Marklund; Gert Brodin; Vladimir Tikhonchuk; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ultra-intense laser; femtosecond pulse; plasma; relativistic phenomena; laser-driven acceleration; attosecond pulse generation; radiation reaction; fysik; Physics;

    Abstract : Rapid progress in ultra-intense laser technology has resulted in intensity levels surpassing 1022 W/cm2, reaching the highest possible density of electromagnetic energy amongst all controlled sources available in the laboratory. During recent decades, fast growth in available intensity has stimulated numerous studies based on the use of high intensity lasers as a unique tool for the initiation of nonlinear behavior in various basic systems: first molecules and atoms, then plasma resulting from the ionization of gases and solids, and, finally, pure vacuum. READ MORE

  7. 5. Spatial and temporal metrology of intense attosecond pulses

    Author : Helene Coudert-Alteirac; Atomfysik; []
    Keywords : 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;

    Abstract : 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. READ MORE