Femtosecond laser-induced periodic surface structures formation on thin films
In the present work, we develop a theoretical and experimental study on the formation of Laser Induced Periodic Surface Structures (LIPSS) on the surface of bismuth and titanium thin films. The light source that we used to produce such structures is an Ytterbium fiber laser (Satsuma HP2, Amplitude S...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | México |
| Institución: | Centro de Investigación Científica y de Educación Superior de Ensenada |
| Repositorio: | Repositorio Institucional CICESE |
| Idioma: | inglés |
| OAI Identifier: | oai:cicese.repositorioinstitucional.mx:1007/3579 |
| Acceso en línea: | http://cicese.repositorioinstitucional.mx/jspui/handle/1007/3579 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Autor/Pulsed Laser, femto-seconds, nano-structures, LIPSS, oxides, titanium, bismuth, Fourier transform, Plasmons, Surface plasmon-polaritons, FDTD info:eu-repo/classification/Autor/Laser pulsado, femtosegundos, nanoestructuras, LIPSS, oxidos, titanio, bismuto, transformada de fourier, plasmones, FDTD info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2209 info:eu-repo/classification/cti/220919 |
| Sumario: | In the present work, we develop a theoretical and experimental study on the formation of Laser Induced Periodic Surface Structures (LIPSS) on the surface of bismuth and titanium thin films. The light source that we used to produce such structures is an Ytterbium fiber laser (Satsuma HP2, Amplitude Systems) producing 270 femto-second pulses at a central wavelength of 1030 nm, frequency repetition rates of 1 kHz and 5 kHz. To determine the required irradiation parameter for producing this LIPSS, we carried out a characterization on the ablation threshold fluence on each film. Furthermore, we proposed to modify a well-known phenomenological model which treats the pulse laser ablation as a cumulative process. Once we have produced the patterns, we use a simple image processing technique based on the Fourier transform of optical and SEM micrographs of the structures. This technique gives us the periodicity, orientation ans dispersion of the LIPSS orientation angle among other significant values. The analysis of the experimental results, shows that the current electromagnetic-based models are adequate to predict the occurrence of LIPSS on both materials as well as their evolution when varying the angle on incidence. Nevertheless, such models are not effective to explain the change on the LIPSS periodicity as the number of pulses is increased. Additionally, we demonstrated the laser-induced oxidation of both materials and the formation of LIPSS on those oxides. Finally, we developed a numerical model based on the Finite Difference Time-Domain method as an attempt to predict the formation and evolution of the patterns that the theoretical models can not. To build the numerical model it is necessary to take into account the actual dielectric properties of the substrate as the characteristics of the pulsed laser. The results are shown at the end of this thesis. |
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