Speaker
Description
The development of low-noise optical coatings is a crucial challenge for improving the sensitivity of current and next-generation gravitational-wave detectors. A key aspect in optimizing these materials is the identification of the most effective post-deposition heat treatment, as annealing strongly influences both the structural and mechanical properties of the coatings. Among the most promising materials, TiO₂-doped SiO₂ and TiO₂-doped GeO₂ coatings have attracted significant attention due to their potential for reduced mechanical dissipation. In this contribution, we review the current understanding of mechanical losses in titania-based coating materials, with particular focus on the role of heat treatment. We then present recent experimental results obtained at the University of Urbino, where the mechanical loss of TiO₂:SiO₂ and TiO₂:GeO₂ coatings for selected concentrations were investigated using a Gentle Nodal Suspension (GeNS) system.