Abstract: An optical disk records digital information in optically-reflective layers that each vary in thickness between constructive interference of a monochromatic light and destructive interference of the said monochromatic light. The difference in the intensity of a reflected light beam subjected to interferometric constructive and destructive interference is used to communicate digital data from the optically-reflective layers and a detector. The optical disk provides for multiple layers of digital information that are tuned for interferometric response at correspondingly different monochromatic wavelengths of light. Another embodiment of the present invention is a mass-production process for making such an interferometric optical disk. Another embodiment of the present invention is a variation that includes layers that are emitting or absorbing depending on dopants.