Sökning: "ultrashort"
Visar resultat 1 - 5 av 57 avhandlingar innehållade ordet ultrashort.
1. Generation and metrology of ultrashort pulses and their application in attosecond science
Sammanfattning : This thesis deals with the dynamical processes in atoms and small molecules initiated by the absorption of ultrashort, coherent light pulses. The studied phenomena takeplace on the femtosecond (1 fs = 10−15 s) and attosecond (1 as = 10−18 s) timescales and critically depend on the properties of the light fields that drive them. LÄS MER
2. Characterisation and Applications of Ultrashort Extreme Ultraviolet Pulses
Sammanfattning : When a strong laser field interacts with free atoms, harmonics up to very high orders are created. This extreme ultraviolet (XUV) radiation has interesting properties, such as spatial and temporal coherence, short pulse duration and high brightness. This thesis concentrates on the temporal aspects of this radiation. LÄS MER
3. Sources and Diagnostics for Attosecond Science
Sammanfattning : Ultrafast science refers to physical events that happen on the femtosecond (1 fs=10^-15 s) and attosecond (1 as=10^-18 s) timescales. Generation of attosecond pulses is usually achieved by interacting high-intensity femtosecond pulses with matter (typically gases), in a process called high-order harmonic generation (HHG). LÄS MER
4. An Intense Attosecond Light Source - Towards Extreme Ultraviolet Pump-Probe Experiments
Sammanfattning : This thesis presents important steps towards performing high-intensity attosecond pump-probe experiments at the Lund high-intensity extreme ultraviolet (XUV) beamline, which followed two complementary paths: maximization of the XUV intensity available in the interaction region with a gas target, and providing attosecond temporal resolution.To maximize the energy of the XUV pulses generated via high-order harmonicgeneration (HHG), the macroscopic response of atoms to the driving infrared field was optimized. LÄS MER
5. Generation of Ultrashort Pulses – From Femtoseconds to Attoseconds
Sammanfattning : Electronic dynamics takes place on the attosecond timescale and can thus only be studied using a tool with attosecond temporal resolution. High harmonic generation (HHG) provides coherent attosecond pulses in the extreme ultraviolet spectral region. LÄS MER