Linnik interferometers for local spectroscopy in the UV, visible and near infrared wavelengths

Abstract Interference microscopy is a powerful optical metrology technique for surface topography and depth characterization of opaque, transparent and semi-transparent materials. This work presents the development of white-light interference microscopes optimized for multimodal measurements, encompassing spectroscopy, colorimetry, and topography. The systems employ a Linnik configuration and are implemented on a breadboard platform, referred to as the "Breadboard-Linnik" (BL). Two configurations are evaluated: a visible-near IR range setup (Visible-NIR BL) covering 460-780 nm and a UV-extended setup (UV-Visible-NIR BL) with hyperspectral coverage spanning 300-900 nm. Quantitative reflectance data are acquired as spectral cubes, enabling detailed spectral and spatial analysis. System's performance is validated using thin films of gold (Au), neodymium-doped tin dioxide (Nd:SnO₂), zirconium dioxide (ZrO2), silicon dioxide (SiO2) or indium tin oxide (ITO) deposited on silicon wafers. The results demonstrate the systems' capability for comprehensive UV-visible analysis, with spectral reflectance maps and high-resolution imaging confirming its suitability for advanced materials characterization.