Improvement of the optical coating process by cutting layers with sensitive monitoring wavelengths

For costly optical coatings, a precise monitoring method is necessary. A new monitoring method based on the selection of the most sensitive monitor wavelength is proposed. The most sensitive monitor wavelength is easy to find by a numerical analysis. The equation for the thickness compensation when a layer is over-shot or under-shot was derived. Several examples, including narrow-band pass filters, have been given to demonstrate that this new method is superior to the turning point method in the coating process.