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 30 for “"Ultrashort Laser"”.
-
Damages in Transparent Materials by Ultrashort Laser Pulse
Ultrashort lasers that generate laser pulses down to picosecond and femtosecond range have advanced over the past decade from delicate lab systems to robust industry machines. The availability of stable ultrashort laser systems opens up a wide range of exciting applications from transparent …
-
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 …
-
Ultrashort laser pulse-matter interaction: Fundamentals and early stage plasma dynamics
… for many years, the detailed mechanisms of ultrashort laser pulse (USLP)-matter interaction are still not fully understood and further fundamental investigation is required. This study seeks to provide an improved understanding of the USLP-material interaction by both theoretical and …
-
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
… with metal carbonyls and diazomethane. Only ultrashort laser pulses allow for excitation and subsequent reaction on a time scale faster than the statistical energy redistribution (IVR).
-
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. …
-
Modeling of nonlinear ultrashort optical pulse propagation
… scripting interface for simulating a host of ultrashort pulse propagation phenomena. With the proliferation of ultrashort laser technologies, the demand for efficient and accurate simulations has grown significantly. Here I introduce a linear-operator-based formalism for nonlinear pulse …
-
SPATIAL CHARACTERIZATION OF LASER FILAMENTS BY DETECTION OF SIGNATURES OF IONIZATION
Laser filamentation is a phenomenon currently being widely studied in which an ultrashort laser pulse self focuses as a result of the nonliner Kerr effect. Lim- ited data is available in terms of spatial characterization of the filament. We study the spatial distribution of molecular and atomic …
-
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, …
-
Kollektive Energieabsorption von Mikroplasmen in starken Laserfeldern
The interaction of strong ultrashort laser pulses with atomic clusters is characterized by an efficient absorption of laser energy and unique features of energy conversion into x-rays, electrons, ions and fusion neutrons. In the present work, absorption of laser light by atomic clusters is studied …
-
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 …
-
Table-top XUV nanoscope
… imaging (CDI). Intense spatially coherent ultrashort XUV and X-ray pulses are desired for nanoscale biological and material imaging. Such radiation can be produced via high harmonic generation (HHG) by focusing a highly intense ultrashort laser pulse into gas. In order to obtain high flux …
-
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 …
Page 1 of 2