Optical multicoating using low-refractive-index SiO2 optical thin films deposited by sputtering and electron beam evaporation

Controlling the refractive index of optical thin-films can improve the optical characteristics of materials. We have developed a combination deposition system that can perform sputtering and electron beam evaporation either separately or simultaneously. The combination deposition system can produce silicon dioxide (SiO2) optical films with refractive indices ranging from 1.26 to 1.47. Using the developed system, we fabricated a monomaterial multilayer coating with 51 layers of SiO2 on a SiO2 substrate, i.e., same material. The wavelength of the as-prepared bandstop was consistent with the designed wavelength. In addition, the light-scattering intensity ratio of the fabricated optical filter was similar to that of conventional filters.