Plasma-ion-assisted deposition: a powerful technology for the production of optical coatings

Plasma-IAD with the APS (advanced plasma source) has been introduced into the market in 1992. Up to now this technique is used worldwide in almost 100 coating systems. A large number of different layer systems has been investigated in R&D and applied in production. For ophthalmic applications plasma-IAD with the APS is used for antireflection systems as well as for wear resistant coatings onto organic substrates. New processes which combine the AR coating and the hardcoating on ophthalmic lenses have been successfully introduced into mass production. Plasma-IAD is also used for laser protection coatings onto plastic substrates. The ability for the production of shift free multilayer coatings is utilized in manufacture for many applications such as steep edge filters for color separation, rugate filters for laser protection, narrow-bandpass filters in the NIR region for wavelength multiplexing in the field of fiber optic communication or for radiometers in the UV-B region. A review of the development of some important APS based coating processes and applications shows the flexibility of plasma-IAD with the APS. Actual evaluations of the optical constants of Ta2O5 layers deposited with APS assistance show a low extinction coefficient and a stable refractive index. New results of the performance, temperature behavior and long term stability of some interference filters confirm high packing density and low absorption of the films produced with plasma-IAD. The result of a reproducibility experiment demonstrates high process stability and high monitoring accuracy.