Sökning: "Fourier transform"
Visar resultat 1 - 5 av 279 avhandlingar innehållade orden Fourier transform.
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
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
2. Optical Frequency Comb Fourier Transform Spectroscopy
Sammanfattning : 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. LÄS MER
3. Leveraging Intermediate Representations for High-Performance Portable Discrete Fourier Transform Frameworks : with Application to Molecular Dynamics
Sammanfattning : 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. LÄS MER
4. Fourier transform and Vernier spectroscopy using optical frequency combs
Sammanfattning : 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. LÄS MER
5. High Resolution Spectroscopy of Singly Charged Ions : Applications of Laser and Fourier Transform Techniques
Sammanfattning : 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. LÄS MER