Advanced characterization of IBAD deposited MgF2, Al2O3, Si, YF3, and Ge thin films in ultra-broadband spectral region of 300-5000 nm

Multilayer optical coatings operating across broad spectral ranges from visible to mid-infrared play a crucial role in numerous industrial and scientific applications. MgF₂, YF₃, and Al₂O₃ are promising low-index materials within this range, Ge and Si can be harnessed as high-index materials. One of the key prerequisites to producing high-quality optical components is accurate knowledge of optical constants of thin-film materials as well as their environmental properties, which are dependent on deposition technology and process parameters. The present study reports characterization of monolayer samples of Ge, Si, YF₃, Al₂O₃, and MgF₂ on Silicon and Fused Silica substrates produced by e-beam evaporation with ion assistance technology. Deposition of the samples was performed at ORTUS-700 vacuum coater (IPhotonics). Reflectance and transmittance were measured using Photon RT spectrophotometer (Essent Optics) in the range 300-5000 nm. The samples were numerically characterized using advanced algorithms of OTF Studio software; layer optical constants were reliably determined.