Investigation of MgF_(2) optical thin films with ultralow refractive indices prepared from autoclaved sols

摘要

We have successfully developed a process to form high quality MgF_(2) thin films with ultralow refractive indices from autoclaved sols prepared from magnesium acetate and hydrofluoric acid. And we have confirmed that our porous MgF_(2) coatings have not only high transmittance in the UV region but also high uniformity of film thickness. They can be uniformly formed on phi 300 mm substrates as a single coating and as a hybrid coating with sublayers formed by physical vapor deposition. They are expected to be applied to various optics that need high transmittance in the UV region.