Understanding optical coating on micro- and macro-scale via metal-layer-amplified second-harmonic generation Project ID: GA25-17822S Provider: Czech Science Foundation Period: Jan 01, 2025 - Dec 31, 2027 Principal Investigator: doc. RNDr. Karel Žídek, Ph.D. Co-investigators M. Hlubučková, P. Elsner, M. Guesmi, K. Hlinomaz, J. Lukeš, J. Budasz, P. Veselá, V. Kanclíř Aims of the project: Optical elements require durable coatings for specific applications such as space missions and high-power lasers. The process of depositing these coatings is complex due to the many factors that affect the layers' microstructure. Furthermore, our understanding of the connection between the microscale structure and the macroscopic coating properties is limited, as microscopic analysis is confined to a few spots and does not represent the larger scale. This project aims to bridge this knowledge gap by developing a metal-layer-enhanced second harmonic generation (MESH) technique. The enhanced nonlinear signal will pave the way for macroscopic scanning of sample inhomogeneities, stress distribution, microstructure variations, and contamination. The project's goal is to optimize the coating process to reduce stress and enhance functional performance. This approach holds promise for broader applications across various fields, enhancing optical coatings for high-power lasers, low-scattering systems, and optics suited for harsh environments.