Sökning: "coherent harmonic generation"

Visar resultat 11 - 15 av 22 avhandlingar innehållade orden coherent harmonic generation.

1. 11. Towards ultrafast imaging with extreme ultraviolet light sources

   Författare :Jörg Schwenke; Lunds universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photo emission electron microscopy; Focusing of X-ray radiation; Digital holography; High-order harmonic generation; Free-electron laser seeding; Secondary electron cascades; Fysicumarkivet A:2012:Schwenke;

   Sammanfattning : This thesis reports experimental studies performed with two advanced coherent XUV sources with ultrashort pulse duration, high-order harmonic generation and seeded-free electron laser. High-order harmonic generation (HHG) is the generation of overtones of a fundamental laser pulse in a medium, e.g. noble gases. LÄS MER

3. 12. Attosecond interferometry: techniques and spectroscopy

   Författare :David Kroon; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2016:Kroon; Electron wave packet; Attosecond Pulse trains; Photoionization; Photoemission time delay; High-order harmonic generation; Interferometry; Electron dynamics;

   Sammanfattning : The interaction between an intense laser pulse and a gas medium leads to the emission of coherent bursts of light in the extreme ultraviolet range. This process, known as high-order harmonic generation, has today, almost three decades after its discovery, developed into a reliable source of extremely short (on the order of 100 as) pulses of electromagnetic radiation, with a wide range of applications in the atomic, molecular and optical sciences. LÄS MER

4. 13. Ultrafast opto-optical control of extreme ultraviolet light pulses

   Författare :Samuel Bengtsson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; extreme ultraviolet; controlled emission; Free induction; time-dependent spectroscopy; noble; High order harmonic generation; phase-control; Fysicumarkivet A:2017:Bengtsson;

   Sammanfattning : Extreme ultraviolet (XUV) light is a valuable frequency range for ultrafast optics experiments. The short wavelength is a requirement for ultrashort pulses, which are widely used to characterize fast dynamics. Additionally, the high photon energy enables quantum control of high frequency transitions in atoms. LÄS MER

5. 14. Time-resolved plasmonics in designed nanostructures

   Författare :Eleonora Lorek; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasmon; Nanostructure fabrication; High-order harmonic generation; Photoemission electron microscopy; Focused ion beam; Fysicumarkivet A:2016:Lorek;

   Sammanfattning : A metal nanoparticle can be considered as consisting of a base of positive ion cores and a sea of free electrons. When the free electrons are displaced, for example, by an incident electric field, a restoring force acts on the electrons. The electrons may then oscillate back and forth until equilibrium is reached. LÄS MER

7. 15. Optical Parametric Devices in Periodically Poled LiTaO3

   Författare :Martin Levenius; Katia Gallo; Valdas Pasiskevicius; Giuseppe Leo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; parametric processes; frequency downconver-sion; quasi-phase matching; LiTaO3; broadband downconversion; quadratic cascading; nonlinear photonic crystals; twin-beam generation;

   Sammanfattning : Optical parametric frequency conversion based on quasi phase matching (QPM) in nonlinear optical crystals is a powerful technique for generating coherent radiation in wavelength ranges spanning from the mid-infrared (mid-IR) to the blue, displaying low thermal load and high efficiency.This thesis shows how QPM in one- (1D) or two-dimensional (2D) lattices can be employed to engineer novel devices for parametric downconversion in the IR, af-fording freedom in designing both spectral and angular properties of the parametric output. LÄS MER