Sökning: "Laser excitation"

Visar resultat 1 - 5 av 111 avhandlingar innehållade orden Laser excitation.

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

    Författare :Maria Ruchkina; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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;

    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

  2. 2. Quantum computing with naturally trapped sub-nanometre-spaced ions

    Författare :Lars Rippe; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Laserteknik; Laser technology; Atom- och molekylärfysik; Atomic and molecular physics; akustik; optik; Elektromagnetism; optics; acoustics; Electromagnetism; Fysik; Physics; entanglement; spectroscopy; rare-earth-metal-ion-doped crystals spectral hole-burning; inversion; excitation; laser stabilization; quantum computation; quantum gate;

    Sammanfattning : The main aim of this work, was to lay the foundations for the experimental realisation of a quantum mechanical controlled NOT gate in rare-earth-metal-ion-doped crystals. Small amounts of rare-earth elements, added during the growth of some inorganic crystals, will become substituted into the crystal lattice as trivalent ions. LÄS MER

  3. 3. Controlled Trapping in Laser Wakefield Accelerators

    Författare :Martin Hansson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Laser; Wakefield; Acceleration; Trapping; Fysicumarkivet A:2016:Hansson;

    Sammanfattning : Experimental studies of laser-driven acceleration of charged particles, in particular electrons and protons, are described in this dissertation. Tightly focused femtosecond laser pulses with intensities exceeding 1018 W/cm2 were used to accelerate charged particles to high energies over distances of a few millimeters. LÄS MER

  4. 4. Development and Application of Rotational Coherent Anti-Stokes Raman Spectroscopy and Laser-induced Fluorescence for Combustion Diagnostics

    Författare :Christian Brackmann; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Laser-induced Fluorescence; Formaldehyde; Biofuel; Laser technology; Laserteknik; Energy research; Energiforskning; Coherent Anti-Stokes Raman Spectroscopy; Combustion; Laser diagnostics; Fysicumarkivet A:2004:Brackmann;

    Sammanfattning : The thesis concerns the development and application of two laser-based methods for combustion diagnostics: dual broadband rotational coherent anti-Stokes Raman spectroscopy (CARS) and laser-induced fluorescence (LIF). In efforts to increase the usefulness of the CARS technique, the applicability of a method involving a combination of the rotational CARS technique and the closely related vibrational CARS technique was investigated. LÄS MER

  5. 5. Photoelectron Spectroscopy on Atoms, Molecules and Clusters : The Geometric and Electronic Structure Studied by Synchrotron Radiation and Lasers

    Författare :Torbjörn Rander; Olle Björneholm; Gunnar Öhrwall; Maxim Tchaplyguine; Matthias Neeb; Uppsala universitet; []
    Nyckelord :Atomic and molecular physics; Free clusters; Electron spectroscopy; Doped clusters; Laser excitation; Alkali metals; Electronic structure; Geometric structure; X-ray photoelectron spectroscopy XPS ; Resonant Auger spectroscopy RAS ; Near-threshold x-ray absorption fine structure NEXAFS ; Ultraviolet photoelectron spectroscopy UPS ; Detuning; Ultra-fast dissociation UFD ; Sodium; Potassium; Oxygen; Bromomethane; Argon; Xenon; Krypton; Molecular field splitting; Core hole lifetime; Core excitation; Atom- och molekylfysik;

    Sammanfattning : Atoms, molecules and clusters all constitute building blocks of macroscopic matter. Therefore, understanding the electronic and geometrical properties of such systems is the key to understanding the properties of solid state objects. LÄS MER