| dc.contributor.advisor | Ihlemann, Jürgen Dr. | |
| dc.contributor.author | Richter, Lukas Janos | |
| dc.date.accessioned | 2023-04-28T13:15:30Z | |
| dc.date.available | 2023-05-05T00:50:09Z | |
| dc.date.issued | 2023-04-28 | |
| dc.identifier.uri | http://resolver.sub.uni-goettingen.de/purl?ediss-11858/14649 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-9862 | |
| dc.format.extent | XXX Seiten | de |
| dc.language.iso | eng | de |
| dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 International | * |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | * |
| dc.subject.ddc | 530 | de |
| dc.title | UV laser modification of transparent materials for photonic applications | de |
| dc.type | cumulativeThesis | de |
| dc.contributor.referee | Hofsäss, Hans Christian Prof. Dr. | |
| dc.date.examination | 2023-04-21 | de |
| dc.subject.gok | Physik (PPN621336750) | de |
| dc.description.abstracteng | Photonic applications have experienced strong growth in recent years. Due to increasing
digitalization and automation in all areas of life, further growth of photonics is expected in the
future. The broad range of photonic applications supports this statement. While photonic
applications used to be dominated by telecommunication through optical fibers, the use of
photonic processes today is manifold. For example, new light sources have been developed in
the form of LEDs (light-emitting diodes) or OLEDs (organic light-emitting diodes). Due to the
ability to emit coherent and intense light, lasers (light amplification by stimulated emission of
radiation) play a key role as a light source in photonics. In materials processing, for example,
lasers enable the structuring or surface modification of materials. Lasers are also used in other
areas of photonics. For all these applications, optically transparent materials are
indispensable. From the design of a laser up to the optics for beam shaping, transparent
materials are required. These are usually glasses, but can also be crystals, ceramics or
polymers. In this thesis the modification of transparent materials by lasers is addressed.
Glasses and amorphous thin films are structured and functionalized with UV lasers. Single
pulse or repetitive laser heating with high spatial resolution enables processes which cannot
easily be accomplished by other methods.
In the first part of the thesis an introduction to the relevant parts of photonics is provided.
The basics of laser materials processing, e. g. laser ablation, are explained in section 1.1.
Examples of laser materials processing are introduced and important experimental
parameters for these applications are explained. In section 1.2, aspects of laser
functionalization of surfaces are discussed. To that end an introduction to relevant physical
properties of transparent materials is given. Subsequently an overview of laser-based
implantation of metal nanoparticles in glass and laser marking of glass surfaces by several
methods is presented. The last part of the introduction, section 1.3, deals with silicon
photonics. The band structures of bulk silicon and silicon nanocrystals are explained and the
resulting optical properties are discussed. A literature review on this topic is provided. At the
end of this chapter, the references of the introduction are provided.
In chapter 2, the manuscripts of this cumulative dissertation are presented. In the first
manuscript (section 2.1), the generation of a black marking on titanium oxide containing glass
by ultraviolet (UV) excimer laser irradiation is presented. The black marking is partly caused
by strong scattering by a microstructure on the glass surface. The laser-induced
microstructure is accompanied by the formation of a titanium-rich and a silicon-rich phase on
the glass surface. A further contribution to the black marking can be attributed to an increased
absorption caused by an oxygen reduction of the titanium oxide. By this technique, for
example, informative markings such as QR codes can be applied to the glass surface. The
process of the fabrication of the marking as well as material analyses are presented. The other
two manuscripts deal with silicon photonics. In section 2.2, a method for photoluminescence
enhancement of silicon nanocrystals inside a silicon suboxide matrix by laser-based
implantation of gold nanoparticles is presented. The results of photoluminescence
measurements are discussed with the help of absorption, Raman and scanning electron microscopy measurements. A coupling of the silicon nanocrystals to the plasmonically active
gold nanoparticles leads to an enhancement of the photoluminescence. The third manuscript
in section 2.3 also deals with the enhancement of photoluminescence of silicon nanocrystals
by UV excimer laser-based methods. Laser irradiation of a silicon suboxide surface leads to an
enhancement of the photoluminescence. The effects of laser irradiation on the silicon
nanocrystals in the silicon suboxide matrix are analyzed by Raman spectroscopy and
transmission electron microscopy, among others. Besides a slight photoluminescence
enhancement due to structural changes of the silicon nanocrystals, there is an enhancement
of the photoluminescence due to a reduction of losses caused by total internal reflection in
the highly refractive silicon suboxide layer.
A summary and a discussion of the presented results is given in chapter 3. The chapter is
divided into the two main topics of laser-based glass marking (section 3.1) and silicon
photonics (section 3.2). For this section, the relevant literature is again provided at the end of
the section. | de |
| dc.contributor.coReferee | Ihlemann, Jürgen Dr. | |
| dc.contributor.thirdReferee | Egner, Alexander Prof. Dr. | |
| dc.contributor.thirdReferee | Moshnyaga, Vasily Prof. Dr. | |
| dc.contributor.thirdReferee | Rizzi, Angela Prof. Dr. | |
| dc.contributor.thirdReferee | Seibt, Michael Prof. Dr. | |
| dc.subject.eng | Laser | de |
| dc.subject.eng | Photonic | de |
| dc.subject.eng | Silicon | de |
| dc.subject.eng | Nanocrystal | de |
| dc.subject.eng | Marking | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-ediss-14649-5 | |
| dc.affiliation.institute | Fakultät für Physik | de |
| dc.description.embargoed | 2023-05-05 | de |
| dc.identifier.ppn | 1843954044 | |
| dc.notes.confirmationsent | Confirmation sent 2023-04-28T13:45:02 | de |