Sökning: "Picosecond laser"

Visar resultat 21 - 25 av 37 avhandlingar innehållade orden Picosecond laser.

1. 21. Generation and Applications of Short-Pulse X-ray Radiation

   Författare :Michael Harbst; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; egenskaper termiska och mekaniska ; Kondenserade materiens egenskaper:struktur; crystallography; phase equilibria; Material science; Condensed matter:stucture; thermal and mechanical properties; time-resolved; X-ray diffraction; kristallografi; fasjämvikt; Material technology; Materiallära; materialteknik;

   Sammanfattning : This thesis summarizes work using hard X-ray radiation on nanosecond and picosecond timescales. The focus is on the experimental part including detailed descriptions of setups for laser pumped - X-ray probe experiments. X-ray diffraction is sensitive to structural properties on the length scale of chemical bonds. LÄS MER

3. 22. 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

4. 23. Development of fluorescence-based techniques for quantitative measurements of combustion species

   Författare :Malin Jonsson; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The work presented in this thesis covers how laser-induced fluorescence (LIF) and photofragmentation laser-induced fluorescence (PF-LIF) can be used to determine quantitative species concentrations in different combustion environments. To attain species concentrations with LIF it is of vital importance to investigate the influence of collisional quenching on the fluorescence signal strength, which can be done by measuring the fluorescence lifetime. LÄS MER

5. 24. Acoustic, Thermal and Non-thermal Dynamics in Condensed Matter Studied by Time-Resolved X-ray Diffraction

   Författare :Carl Ekström; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; X-ray diffraction; Time-resolved; Ultrafast; Non-thermal melting; Thermal conductivity; Pressure wave; Opto-acoustic transducer; Fysicumarkivet A:2020:Ekström;

   Sammanfattning : The method of using short laser and X-ray pulses to investigate dynamics in materials (pump-probe) has been used for several decades. This thesis presents work that was carried out using these sources of light to reveal acoustic, thermal and non-thermal dynamics. LÄS MER

7. 25. 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