Search for dissertations about: "Fourier transform"

Showing result 1 - 5 of 278 swedish dissertations containing the words Fourier transform.

  2. 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

    Author : Joachim A. Terschlüsen; Johan Söderström; Margaret Murnane; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Optical Frequency Comb Fourier Transform Spectroscopy

    Author : Alexandra C. Johansson; Aleksandra Foltynowicz; Ove Axner; Jürgen Röpcke; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Optical frequency comb spectroscopy; Fourier transform; molecular absorption dispersion; fysik; Physics;

    Abstract : Fourier transform spectroscopy (FTS) based on optical frequency combs is an excellent spectroscopic tool as it provides broadband molecular spectra with high spectral resolution and an absolutely calibrated frequency scale. Moreover, the equidistant comb mode structure enables efficient coupling of the comb to enhancement cavities, yielding high detection sensitivity. READ MORE

  5. 3. Leveraging Intermediate Representations for High-Performance Portable Discrete Fourier Transform Frameworks : with Application to Molecular Dynamics

    Author : Måns Andersson; Stefano Markidis; Artur Podobas; Niclas Jansson; Ivy Bo Peng; Hartwig Anzt; KTH; []
    Keywords : Intermediate Representation; Discrete Fourier Transform; Fast Fourier Transform; Molecular Dynamics; Mellankod; diskret Fouriertransform; snabb Fouriertransform; Molekyldynamik;

    Abstract : The Discrete Fourier Transform (DFT) and its improved formulations, the Fast Fourier Transforms (FFTs), are vital for scientists and engineers in a range of domains from signal processing to the solution of partial differential equations.  A growing trend in Scientific Computing is heterogeneous computing, where accelerators are used instead or together with CPUs. READ MORE

  6. 4. Fourier transform and Vernier spectroscopy using optical frequency combs

    Author : Amir Khodabakhsh; Aleksandra Foltynowicz; Ove Axner; Frans Harren; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; optical frequency comb spectroscopy; molecular absorption; resonant cavity; Fourier transform spectroscopy; Vernier spectroscopy; fysik; Physics;

    Abstract : Optical frequency comb spectroscopy (OFCS) combines two previously exclusive features, i.e., wide optical bandwidth and high spectral resolution, enabling precise measurements of entire molecular bands and simultaneous monitoring of multiple gas species in a short measurement time. READ MORE

  7. 5. High Resolution Spectroscopy of Singly Charged Ions : Applications of Laser and Fourier Transform Techniques

    Author : Jonas Gurell; Sven Mannervik; Richard Holt; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Atomic physics; Atomfysik; fysik; Physics;

    Abstract : This thesis presents measurements of fundamental properties of singly charged ionic systems including spectral wavelengths, lifetimes of excited states and branching fractions with the main focus on time resolved laser spectroscopy of stored ions providing lifetime measurements of metastable states. The results of these measurements have been used to determine energy levels and transition probabilities of the studied systems. READ MORE