Antireflective coatings with high damage threshold prepared by laser ablation

• Published in: Applied physics. A, Materials science & processing Vol. 125; no. 12; pp. 1 - 12
• Main Authors: Filipescu, M., Palla-Papavlu, A., Bercea, A., Rusen, L., Cernaianu, M. O., Ion, V., Calugar, A., Nistor, L. C., Dinescu, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2019; Springer Nature B.V
• Subjects: Aluminum oxide; Antireflection coatings; Applied physics; Atomic force microscopy; Characterization and Evaluation of Materials; Condensed Matter Physics; Hafnium oxide; Heterostructures; High power lasers; Laser ablation; Laser damage; Lasers; Machines; Manufacturing; Materials science; Metal oxides; Morphology; Nanotechnology; Optical and Electronic Materials; Optical properties; Parameter modification; Physics; Physics and Astronomy; Processes; Pulsed laser deposition; Pulsed lasers; Room temperature; Sapphire; Silicon dioxide; Spectroellipsometry; Stability; Surfaces and Interfaces; T.C.: Dedicated to Maria Dinescu; Thin Films; Titanium; Yield point
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-019-3110-y

Latest developments in the field of high power ultra-short pulse lasers have led to intensive studies dedicated to the fabrication possibility of new antireflective coatings which exhibit high damage threshold. Therefore, this study is focused on the deposition and characterization of metal oxide heterostructures followed by laser-induced damage threshold tests which evidence their application in high power laser optics. Al 2 O 3 , SiO 2 , and HfO 2 layers are combined to obtain different heterostructures, i.e. HfO 2 /Al 2 O 3 /HfO 2 /Al 2 O 3 /HfO 2 and HfO 2 /SiO 2 /HfO 2 /SiO 2 /HfO 2 . The metal oxide heterostructures are deposited in a controllable oxygen atmosphere, either at room temperature or high temperatures (600 °C) by pulsed laser deposition (PLD). The morphological, structural and optical properties of the as-deposited heterostructures are first investigated. Atomic force microscopy and spectroscopic ellipsometry investigations reveal a lower roughness of the heterostructures based on HfO 2 /Al 2 O 3 layers grown at 600 °C as compared to those grown at room temperature. Furthermore, following the laser-induced damage threshold (LIDT) tests carried out with a Ti–Sapphire laser, higher LIDT values are obtained for the HfO 2 /Al 2 O 3 -based heterostructures than for the HfO 2 /SiO 2 -based heterostructures. The ability to control the morphological and structural properties of the antireflective coatings by modifying the deposition parameters of the metal oxide heterostructures demonstrates that PLD is a suitable technique for the manufacturing of antireflective coatings for high power ultra-short laser systems.