2 nm-thick germanium film deposited directly on SiO2 substrate
A. Ciesielski, L. Skowronski, W.Pacuski, T. Szoplik. Permittivity of Ge, Te and Se thin films in the 200–1500 nm spectral range. Predicting the segregation effects in silver, Mat. Sci. Semicond. Process.81, 64-67 (2018) (Numerical data kindly provided by Arkadiusz Ciesielski)
Germanium is a popular optical material for infrared wavelengths. Ge optical components (lenses, filters, beamsplitters etc.) are used in thermal imaging, CO2 lasers, night vision systems and other applications in mid-wave infrared (MWIR) and long-wave infrared (LWIR).