Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 20 for “"Ultrashort Laser Pulses"”.
-
Atoms in intense ultrashort laser pulses and the absolute phase
… atomarer Prozesse in intensiven ultrakurzen Laserpulsen. Der Schwerpunkt liegt hierbei bei den Zwillingseffekten der Erzeugung hoher Harmonischer (``high-order harmonic generation'', HHG) und der Ionisation über Zustände im Kontinuum (``above-threshold ionization'', ATI). Besonders letzterer …
-
Nanometer scale observation of magnetization textures induced by ultrashort laser pulses
The manipulation of magnetic order with ultrashort laser pulses has become a vivid field in modern magnetism research. Laser pulses have been found to not only demagnetize magnetic materials on a femtosecond timescale, but even reverse the magnetization in certain (anti-)ferromagnetically coupled …
-
COMPLETE TEMPORAL MEASUREMENT OF LOW-INTENSITY AND HIGH-FREQUENCY ULTRASHORT LASER PULSES
Two important frontiers in the field of ultrashort pulse measurement are the complete temporal measurement of low-intensity picosecond pulses in the near-infrared (NIR) and intense ultrashort pulses in the ultraviolet (UV) and extreme ultraviolet (EUV). The former are projected to find great use in …
-
Photoelectron Spectroscopy of highly oriented pyrolytic graphite using intense ultrashort laser pulses
… Highly Oriented Pyrolytic Graphite (HOPG) using ultrashort laser pulses. It concentrates on the observation and understanding of a new phenomenon whereby infrared laser pulses of just 1.5eV photon energy can be used to generate photoelectrons with kinetic energies of up to 80eV. Intensity …
-
Molekulare Dissoziation im elektronischen Grundzustand induziert durch Femtosekundenpulse im mittleren Infrarot
… exciting molecular vibrations with femtosecond pulses in the mid-infrared. Vibrational ladder-climbing to high excitation levels (v=7-8) provides the necessary energy for bond scission. This excitation scheme was demonstrated with metal carbonyls and diazomethane. Only ultrashort laser pulses …
-
Optical Filaments and Gas Dynamics in Air
Until now, the propagation dynamics of intense ultrashort laser pulses leading to optical filamentation in air has only been investigated in the frame of a dynamic balance between linear diffraction, Kerr self-focusing and plasma defocusing. This has led to the development of different theories …
-
Modeling phonon-polariton generation and control in ferroelectric crystals
… nonlinear electro-optic interactions with ultrashort laser pulses. This direct space-time monitoring platform is used to investigate the nature of the excitation mechanism, the science of propagation in patterned structure, and the waveform control via multi-dimensional pulse shaping. …
-
Lūžio rodiklio modifikavimas stikluose ir kristaluose veikiant ultratrumpaisiais lazerio impulsais /
… index modification of transparent materials with ultrashort laser pulses is presented in this dissertation. Based on experimental data it was demonstrated, that using ultrashort pulses, generated with Yb:KGW laser system, it is possible to produce modified refractive index zones in the fused …
-
Controlling molecules with lasers and lasers with molecules
… of spin in molecules using shaped ultrafast lasers and the dynamics of those lasers when their cavities are modified to include programmable molecular masks. The ability to control quantum phenomena has had several large successes over the last decade. This field, known as Quantum Control, …
-
Two-dimensional ultrafast pulse shaping and its application to coherent control and spectroscopy
… powerful new methods for shaping femtosecond laser pulses in two dimensions and explores their application to coherent control of propagating lattice excitations and degenerate four-wave mixing spectroscopy. Pulse shaping in two dimensions is achieved by manipulating the spectral components of …
-
Femtosecond Pulse Compression via Self-Phase Modulation in 1-Decanol
… in and outside the realm of physics. Ultrashort laser pulses on the order of femtoseconds (1 fs = 1 × 10−15 s) are widely used for ultrafast science. Many lasers can produce pulses on the order of 100 fs, with state of the art, high end lasers being capable of producing pulses around …
-
Ultrafast Atomic Dynamics in Arbitrary Light Fields
… atomic processes in arbitrarily polarised laser fields is described. The theory is applicable to multielectron atoms and atomic ions subject to ultrashort laser pulses with any given ellipticity, and generalises previous time-dependent R-matrix techniques restricted to linearly polarised …
-
Plonasluoksnių galio nitrido dangų modifikavimas lazerine femtosekundine UV spinduliuote /
… these devices effectively. Advancements in ultrashort pulse laser technology have enabled high-precision micro-processing of materials. Ultrashort laser pulses, compared to longer pulses, offer better control in the ablation process and enhance the resolution of micro-processing due to …
-
Laserstrukturierung von Mikroprägewerkzeugen und Abformung beugungsoptisch wirksamer Gitterstrukturen
… Arbeit werden Ergebnisse der Untersuchungen zur Laserstrukturierung von Prägewerkezeugen sowie zur Abformung von Gitterstrukturen mit Gitterperioden von kleiner gleich 2 µm in verschiedene Folien und Werkstoffverbunde präsentiert und diskutiert. Die hierfür entwickelte Kombination von …
-
Characterization of Organic and Inorganic Optoelectronic Semiconductor Devices Using Advanced Spectroscopic Methods
… and vertical cavity surface emitting lasers (VCSEL). Experiments include single photon and two-photon excitation with lasers, with subsequent measurements of the absorption and photoluminescence, as well as photocurrent measurements using tungsten and xenon lamps, measuring the direct …
-
Coherent Control of Molecular Dynamics with Shaped Femtosecond Pulses
… quantum mechanical systems with suitably shaped ultrashort laser fields. The coherence properties of the laser field are exploited to achieve constructive interference for a predefined target wave function via a phasecorrect superposition of wave functions. The goal of coherent control, the …
-
Konzeption und Umsetzung neuer Technologien zur biaxialen Winkelmessung und elektrooptischen Pseudostreckenmessung
… aufgehängte Etalon, die temperaturstabilisierte Laseroptik und die temperaturkalibrierte CCD der Winkelmesseinheit (Reflexgoniometer), die Systeme zur Erzeugung und Detektion ultrakurzer Laserpulse, eine elastische Optik, Möglichkeiten zur Formung des transversalen Strahlprofils, das TCSPC-System …