filmsinterferens
Filmsinterferens, or thin-film interference, is the optical phenomenon in which light waves reflected from the two boundaries of a thin film interfere with each other. The result is patterns of bright and dark fringes or, more commonly, vivid colors that depend on the film’s thickness, refractive index, the light’s wavelength, and the angle of observation.
Mechanism: When light encounters a thin film, part is reflected at the top surface and part enters
Mathematical note: For normal incidence, a common simplified condition is 2 n t ≈ (m + 1/2) λ for
Occurrences and applications: The colorful appearance of oil films on water or soap bubbles is a familiar
Limitations and notes: The observed colors depend on viewing angle and lighting, making the effect often iridescent