| SM ISO690:2012|
FILIPESCU, Mihaela; BERCEA, Adrian; NISTOR, L.; NISTOR, S.; COLCEAG, D.; ION, Valentin; MOLDOVAN, Antoniu; DINESCU, Maria. Antireflective coatings for high power laser optics produced by RF-PLD: the influence of the substrate temperature. In: Central and Eastern European Conferenceon Thermal Analysis and Calorimetry. Editia 4, 28-31 august 2017, Chişinău. Germany: Academica Greifswald, 2017, p. 368. ISBN 978-3-940237-47-7.
|Central and Eastern European Conference
Editia 4, 2017
Conferința "Central and Eastern European Conference" |
4, Chişinău, Moldova, 28-31 august 2017
The aim of this work is to report our progress on the obtaining and characterization of antireflective (AR) coatings from dielectric oxides for high power laser systems. For these reason, thin films of tantalum, hafnium, aluminum and silicon oxides were grown as mono / double/ triplelayers by pulsed laser deposition assisted by a radio-frequency discharge beam (RF-PLD). The samples consisting of two / three layers (SiO2 / HfO2, SiO2 / Al2O3, SiO2 / Ta2O5, HfO2 / SiO2 / HfO2) were deposited on quartz substrates, substrates heated at different temperatures and placed in a controllable oxygen atmosphere. In order to asses our results and furthermore improve them, we employed: Atomic force microscopy, Scanning electron microscopy, Transmission electron microscopy, Secondary ion mass spectrometry, X-ray diffraction and spectro-ellipsometry techniques to investigate the resulting samples. Our results highlight the fact that structures based on HfO2 and SiO2 layers have a lower roughness than the structures with Al2O3 or Ta2O5 as bottom layer. Moreover, using HfO2 as bottom layer induces a nanostructured growth of the top layer. Also, on the triple-layer AR coating, we observed that despite the fact that the value of the refractive index “n” of the HfO2 bottom layer is a standard value for this material, the refractive index of the HfO2 top layer is much lower. This decrease is likely due to the fact that the top layer of material probably contains some voids.