Feasibility study on broadband transmittance monitoring for thickness control during double-sided coating

Optical interference coatings are often applied on both sides of a substrate. We show a concept for an adaptation of broadband monitoring of layer thickness for coating machines that allow simultaneous stack deposition. The underlying algorithm can be used to calculate the optical response of a single substrate with coating stacks on both sides, as well as two substrates mounted on top of each other with a coating stack on one side each.