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The theory of thin film optics is well developed for the spectral analysis of a given optical coating.
The inverse synthesis - designing an optical coating for a certain spectral performance - is more
complicated. Usually a multitude of theoretical designs is feasible because most design problems
are over-determined with the number of layers possible with three variables each (n, k, t). The
expertise of a good thin film designer comes in at this point with a mostly intuitive selection of
certain designs based on previous experience and current manufacturing capabilities.
Manufacturing a designed coating poses yet another subset of multiple solutions, as thin if in
deposition technology has evolved over the years with a vast variety of different processes. The
abundance of published literature may often be more confusing than helpful to the practicing thin
film engineer, even if he has time and opportunity to read it. The choice of the right process is
also severely limited by the given manufacturing hardware and cost considerations which may not
easily allow for the adaption of a new manufacturing approach, even if it promises to be better
technically (it ought to be also cheaper). On the user end of the thin film coating business, the
typical optical designer or engineer who needs an optical coating may have limited or no knowledge
at all about the theoretical and manufacturing criteria for the optimum selection of what he needs.
This can be sensed frequently by overly tight tolerances and requirements for optical performance
which sometimes stretch the limits of mother nature. We introduce here a know1edge-based system
(KBS) intended to assist expert designers and manufacturers in their task of maximizing results and
minimizing errors, trial runs, and unproductive time. It will help the experts to manipulate
parameters which are largely determined through heuristic reasoning by employing artificial
intelligence techniques. In a later state, the KBS will include a module allowing the layman user
of coatings to make the right choice.
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