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@PHDTHESIS{Kalupka:760909,
author = {Kalupka, Christian},
othercontributors = {Poprawe, Reinhart and Nolte, Stefan},
title = {{E}nergiedeposition von ultrakurz gepulster
{L}aserstrahlung in {G}läsern; 1. {A}uflage},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Aachen},
publisher = {Apprimus Verlag},
reportid = {RWTH-2019-04495},
isbn = {978-3-86359-713-9},
series = {Ergebnisse aus der Lasertechnik},
pages = {1 Online-Ressource (III, 141 Seiten) : Illustrationen},
year = {2019},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, RWTH Aachen University, 2019},
abstract = {Processing glasses with laser radiation can be achieved by
the application of high intensities for focused ultrashort
pulsed laser radiation even for wavelengths for which the
glass is intrinsically transparent. Absorption of the laser
pulse is realized by nonlinear ionization mechanisms, which
subsequently can lead to a permanent modification of the
glass for a specific local energy deposition. The spatial
distribution of the energy deposition is strongly influenced
by nonlinear and linear interaction and propagation effects,
which are subject of current research. In this dissertation
fundamental correlations of the energy deposition of
ultrashort pulsed laser radiation with the spatial and
temporal intensity distribution of the laser radiation are
elaborated to increase the energy deposition while the
spatial localization is as high as possible. Initially, a
fundamental understanding of the correlation of the temporal
intensity distribution, which is characterized by the pulse
duration and the peak intensity, with the underlying
ionization and interaction processes is developed. In
dependency on the used pulse duration, intensity regimes are
identified for which a dense free electron densityis mainly
induced due to Photo and Avalanche ionization, respectively.
The underlying ionization mechanisms Photo and Avalanche
ionization have a direct impact on the
pulse-plasma-interaction, which is a central measure of the
energy deposition. In the next step the spatial energy
deposition of ultrashort pulsed laser radiation in the
volume of glass is evaluated for the use of a Gaussian
intensity profile by time-resolved investigations of the
dynamics of the induced free electron density. To quantify
the energy deposition, the amplitude and the localization of
the energy deposition are introduced. The amplitude
corresponds to the spatially integrated free electron
density and the localizationis correlated to the spatial
dimension of the free electron density with regard to the
spatial intensity distribution. An increase of the amplitude
of the energy deposition by an increase of the applied
intensity leads to a decrease of the localization due to the
caustic of the Gaussian beam profile. For a nearly
independent adjustment of amplitude and localization of the
energy deposition in glasses, a non-diffracting Bessel beam
profile is generated by spatial beam shaping. In dependency
on the pulse-plasma-interaction, different intensity regimes
are identified. By an precise adjustment of the
pulse-plasma-interaction, a homogenous energy deposition is
achieved with a transverse dimension ∼ 1 μm and a
longitudinal dimension ∼ 700 μm. Finally, on the basis of
the developed fundamental understanding, a cutting process
for glasses is realized by a precisely controlled and
homogenous energy deposition in the glass volume. With this
process, cutting speeds in the order of ∼ 10 mm/s can be
achieved.},
cin = {418710},
ddc = {620},
cid = {$I:(DE-82)418710_20140620$},
typ = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
doi = {10.18154/RWTH-2019-04495},
url = {https://publications.rwth-aachen.de/record/760909},
}
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