ERC Project Launch: COINED – Control over Interfaces in Metal Oxide Optical Coatings

As of July 1, 2025, we have launched a five-year research project titled COINED – Control over Interfaces in Metal Oxide Optical Coatings: the Missing Piece of the Puzzle (Project No. 101171288), funded by the European Research Council (ERC).

Multilayer thin-film coatings grant optical elements their unique functionality, such as high-reflective mirrors or dichroic filters. However, these coatings are often the first to degrade under intense laser light, corrosion, or mechanical stress. A critical weak point lies in the interfaces—both between the substrate and the coating, and between individual layers. While the bulk properties of coating materials are well understood, control over the interfaces remains highly limited.

The COINED project aims to overcome this barrier. By employing a structured laser pulse to generate acoustic waves and simultaneously induce second-harmonic generation (SHG), the project will enable nanometer-scale longitudinal resolution in interface characterization. This novel approach will allow researchers to reveal the morphology of individual interfaces in multilayer coatings and examine how deposition processes, post-treatment, or aging contribute to the formation of unwanted interlayers, defects, or structural changes.

This breakthrough in interface control is expected to have a transformative impact on the development of space-grade optics, increase the achievable laser power, and extend the operational lifetime of UV optics. The project’s outcomes will further reach into other domains such as photovoltaics and nanotechnology.

Project duration: 60 months
Total budget: €1,957,125

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon Europe research and innovation programme (Grant Agreement No. 101171288).