Abstract

Many optical filtering problems require the use of assemblies of layers having thicknesses which bear no obvious relationship to each other. After a brief review and comparison of some numerical techniques of synthesis which are used to obtain specific designs with given properties, we discuss the problems connected with production. The stacks are realized by Ion Assisted Deposition and Ion Plating techniques. For each technique we have reached a good knowledge of the refractive indices of the layers that we can produce starting from different materials (TiO₂, Ta₂O₅, SiO₂, ..) and we can demonstrate that conditions of deposition are correctly adjusted in order to prevent any shift of refractive index between vacuum (during growth of the film) and air (after deposition).

© 1992 Optical Society of America