Optical coating process simulation and reverse engineering

摘要

We often want to determine the structure of manufactured optical coatins. This is typically performed by measuring the coating is a spectrometer and using refinement-based approaches to derive optical constant information and layer thicknesses. The measurement process introduces errors into the measured parameters. The effect of simple errors is often to introduce complex structures into the reverse engineered design such as inhomogeneith. These structures are, in general, plausible as they are complatible with known film behavior. We must be careful to ensure that all measuring equipment is properly maintained and calibrated to minimize these effects and be aware when looking at reverse engineering results that such effects exist.