Sökning: "ultrafast lasers"

Visar resultat 21 - 25 av 31 avhandlingar innehållade orden ultrafast lasers.

1. 21. Escape from the cage: Ultrafast structural dynamics of photodissociation reactions observed with X-ray solution scattering

   Författare :Amke Nimmrich; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The environment of a molecule is known to greatly impact the course of a reaction. Such an environment can, for instance, be the solvent in a solution phase reaction or the amino acid residues surrounding a chromophore in photoreceptor proteins. LÄS MER

3. 22. Time-Resolved Attosecond Spectroscopy of He Using COLTRIMS

   Författare :Predrag Ranitovic; Reinhold Schuch; C. L. Cocke; Robert Moshammer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; attosecond spectroscopy; Physics; Fysik; Physics; fysik;

   Sammanfattning : Tunable ultrafast lasers are becoming a standard tool for probing and controlling the dynamics of atoms, molecules and chemical reactions. This thesis is a contribution to a large, ongoing effort to make spectroscopic tools for inducing and controlling, in real time, the natural processes which occur on the femto and attosecond times scales. LÄS MER

4. 23. Time-resolved optical characterisation of defect-rich semiconductors

   Författare :Andreas Gaarder; KTH; []
   Nyckelord :;

   Sammanfattning : This thesis explores carrier trapping and recombination indefect-rich semiconductors, and methods for materialcharacterisation. Optimal manufacturing parameters areestablished for materials to be used in the ultrafast devicesneeded for future telecommunication applications. LÄS MER

5. 24. Spectral Control of Functional Fiber Sources

   Författare :Robert Lindberg; Valdas Pasiskevicius; Stefano Taccheo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optics and Photonics; Optik och fotonik;

   Sammanfattning : This thesis is based on five projects aimed at spectral control of fiber-based laser architectures. Two of these concern electrically wavelength-tunable laser sources, namely a fiber amplifier system for CO2-monitoring and a novel tunable laser design for flexible pulsed operation. LÄS MER

7. 25. Spin dynamics in the terahertz regime

   Författare :Kumar Neeraj; Stefano Bonetti; Markus Kowalewski; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

   Sammanfattning : It is known that the use of conventional optical lasers for the study of ultrafast magnetization dynamics imparts heat to the materials under study, which creates a highly non equilibrium state and masks the fundamental coupling processes leading to ultrafast demagnetization. In order to understand, control and manipulate the dynamics of spins in magnetic systems a new kind of radiation called terahertz (THz) is starting to be used in recent years. LÄS MER