Is there a good way to calculate the spectral response of a multilayer coating?  I want to model several different bandpass filters using dielectric multilayers, at various angles of incidence.  I know how to simulate a known filter by adding the spectral characteristics into a coating file, but this assumes I already know the spectral characteristics of the coating.  I’ve tried adding multiple layers in non-sequential mode, both of varying dielectrics and partially reflective layers, but the spacing seems too small to register properly.