Sökning: "ultrafast laser spectroscopy"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden ultrafast laser spectroscopy.

  1. 1. Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy

    Författare :Joachim A. Terschlüsen; Johan Söderström; Margaret Murnane; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Angle-resolved photoemission spectroscopy; Angle resolved photoemission spectroscopy; Angle-resolved time-of-flight; Angle resolved time of flight; ARTOF; ARPES; tr-ARPES; fs; fs resolution; Fourier transform spectrometer; Fourier-transform spectrometer; Fourier transform spectroscopy; Fourier-transform spectroscopy; FTS; gas cell; high harmonic generation; laser; liquid jet; monochromator; HELIOS; HHG; off-plane mount; off plane mount; OPA; optical parametric amplifier; PCPDTBT; pulse shaping; pump probe; pump-probe measurements; pump-probe measurements; pump-probe spectroscopy; pump-probe spectroscopy; Rowland spectrometer; time-of-flight spectrometer; time of flight spectrometer; TOF; time-resolved spectroscopy; time resolved spectroscopy; time-resolved experiments; time resolved experiments; T-MOKE; tr-PES; PES; photoelectron spectroscopy; transverse magneto optical Kerr effect; transverse magneto-optical Kerr effect; ultrafast; ultra-high vacuum; ultra high vacuum; UHV; XUV; VUV; X-rays; Permalloy; magnetization dynamic; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. LÄS MER

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

    Författare :Maria Ruchkina; Förbränningsfysik; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Ultrafast, Non-Equilibrium Electron Transfer Reactions of Molecular Complexes in Solution

    Författare :Jonas Petersson; Leif Hammarström; Antonín Vlček; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron transfer; laser; spectroscopy; transient absorption; anisortopy; inter ligand electron transfer; dye sensitized solar cell; DSSC; vibrational relaxation; ultrafast dynamics; fs spectroscopy; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

    Sammanfattning : Photoinduced electron transfer is a fundamentally interesting process; it occurs everywhere in the natural world. Studies on electron transfer shed light on questions about the interaction between molecules and how the dynamics of these can be utilized to steer the electron transfer processes to achieve a desired goal. LÄS MER

  5. 4. 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. 5. Shining Light on Molecules : Electron Transfer Processes in Model Systems for Solar Energy Conversion Investigated by Transient Absorption Spectroscopy

    Författare :Jens Föhlinger; Leif Hammarström; Davidsson Jan; Benjamin Dietzek; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photophysics; photoinduced electron transfer; transient absorption spectroscopy; laser spectroscopy; solar energy conversion; p-type DSSCs; Charge separation; recombination; mesoporous NiO;

    Sammanfattning : In the recent years, solar energy conversion has attracted a huge research interest due to the potential application for limiting the greenhouse effect. In many solar cells and solar fuel cells, understanding of charge transfer (CT) and recombination is important for future improvement of the overall efficiency. LÄS MER