Research Article

UV coatings using Ta₂O₅-SiO₂ quantized nanolaminates

¹ RhySearch, Institute for Optical Coatings and Characterization, Werdenbergstrasse 4, 9470 Buchs, Switzerland
² Evatec Ltd, Hauptstrasse 1a, 9477 Trübbach, Switzerland
³ EMPA, Laboratory for Mechanics of Materials & Nanostructures, Feuerwerkerstrasse 39, 3602 Thun, Switzerland

^* Corresponding author: manuel.baertschi@rhysearch.ch

Received: 31 January 2025
Accepted: 15 April 2025

Abstract

The use of Quantized Nanolaminates (QNL) in optical interference coatings has gained significant attention in recent years. By using a magnetron sputtering tool from Evatec with rotating substrate table and multiple sputtering sources operating simultaneously, we are able to deposit these metamaterials consistently at exceptionally high rates, comparable to and sometimes even exceeding magnetron sputter rates for standard materials. This combination of high deposition rate and precision enables us to treat QNL as a stand-alone material, effectively replacing high-refractive index materials in complex interference filter designs. In our experiments, we used a combination of Ta₂O₅-SiO₂ QNL to produce filters like anti-reflective and shortpass coatings within the UV range of 266–350 nm, which would be not possible with Ta₂O₅ as bulk material in similar designs.