Тему тонких пленок для просветления проходят в средней школе по физике, если мне память не изменятет.
Вот что нашел в Википедии
From Wikipedia, the free encyclopedia.
Thin-film optics is the branch of optics which deals with very thin structured layers of different materials. In order to exhibit thin-film optics, the thickness of the layers of material must be on the order of the wavelengths of visible light (about 500 nm). Layers at this scale can have remarkable reflective properties due to light wave interference and the difference in refractive index between the layers, the air, and the substrate. These effects alter the way the optic reflects and transmits light. You can observe these effects every day in soap bubbles and oil slicks.