Evaluation of the potentialities of the micro-roughness characterization via replica approach

In the development of next generation telescopes, the quality of optical surfaces in terms of micro-roughness is an important parameter for determining their performance and it is constantly monitored during the manufacturing process. While portable instruments are commonly employed for on-surface monitoring, their feasibility diminishes with large or immobile optics in case of complex geometry. In such scenarios, the replica approach emerges as a highly efficient alternative, involving the acquisition of imprints on surfaces with specialized pastes. This paper aims to systematically characterize the measurement process by comparing standard methods with the replica approach. Samples of diverse materials and surface qualities will be measured at various manufacturing stages. The goal is to optimize the process, providing a comprehensive insight into its advantages and effectiveness.