Sökning: "Picosecond and femtosecond spectroscopy"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Picosecond and femtosecond spectroscopy.

  1. 1. Fundamental interactions in transition metal reactions

    Författare :Michael R. Coates; Michael Odelius; Markus Kowalewski; Abhik Ghosh; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; electronic structure; multiconfigurational; density functional theory; molecular dynamics; excited state molecular dynamics; non-adiabatic dynamics; solvation; organometallic complexes; x-ray absorption spectroscopy; photoelectron spectroscopy; time-resolved spectroscopy; femtosecond; picosecond; kemisk fysik; Chemical Physics;

    Sammanfattning : Transition metal complexes that participate in homogeneous reactions often perform the role of a catalyst, facilitating novel reaction pathways. When these complexes are pushed away from their equilibrium, the arrangement of the coordinating ligands around the metal center is perturbed and new reaction pathways are opened. LÄS MER

  3. 2. Molecular Trees for Collecting Sunshine -Monitoring and Controlling Energy Transfer in Dendrimers

    Författare :Jane Larsen; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetiska och optiska ; supraledare; magnetisk resonans; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; supraconductors; magnetic resonance; relaxation; spectroscopy; Condensed matter:electronic structure; electrical; magnetic and optical properties; Kemi; Chemistry; Femtosecond transient absorption; Os-Ru metal ligand complexes; Cu-porphyrin-appended dendrimers; Zn-porphyrin-appended dendrimers; Annihilation; Energy transfer; Solar energy conversion; Artificial photosynthesis; Antenna systems; spektroskopi; Physical chemistry; Fysikalisk kemi; Photochemistry; Fotokemi; Femtosecond fluorescence anisotropy;

    Sammanfattning : A continuing use of fossil fuels will accelerate global warning and result in severe consequences for the environment and thereby also us. Development of alternative, sustainable and environmentally friendly energy sources is therefore crucial. One approach is to create an artificial photosynthetic system that converts sunshine into fuel (e.g. LÄS MER

  4. 3. 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

  5. 4. High-Order Harmonics- Characterisation, Optimisation and Applications

    Författare :Claire Lyngå; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-harmonic generation; VUV spectroscopy; high-power lasers; Atomic and molecular physics; radiative lifetimes; XUV spectroscopy; Atom- och molekylärfysik; Fysicumarkivet A:1999:Lyngå;

    Sammanfattning : Recent advances in laser technology, with the development of extremely short-pulse, high-intensity lasers, have opened doors to new areas in atomic physics. By focusing light from an intense, short-pulse laser into a gas jet, the emission of high-order harmonics of the laser frequency has been studied. LÄS MER

  7. 5. Applications of Short Extreme Ultraviolet Pulses to the Spectroscopy of Atoms and Molecules

    Författare :Allan Johansson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-order harmonics; short pulses; pulse characterisation; sidebands; lifetime measurements; time domain spectroscopy; frequency domain spectroscopy; He; N2; CO; XUV; Atomic and molecular physics; relative polarisation; Atom- och molekylärfysik; Fysicumarkivet A:2003:Johansson;

    Sammanfattning : This thesis is devoted to the characterisation in time and frequency, and to spectroscopic application, of extreme ultraviolet (XUV) pulses. High-order harmonic generation or wave mixing processes were used to produce the pulses in the XUV spectral region. LÄS MER