Isoréflectance des dépôts optiques en couches minces

With the addition of some particular layers, characterized in this note, a periodic non-absorbing optical multilayer allows us to keep the reflectance (or the transmittance) unchanged whatever the number of sequences in the coating. This invariant property, called isoreflectance (or isotransmittance) can be obtained only for a wavelength located inside the passband of the filter. Isoreflectance stretches the buffer single layer concept to multilayer and can be useful in the design of optical coatings.