White light is sent downward onto a horizontal thin film that is sandwiched between two materials. The indexes of refraction are 1.80 for the top material, 1.65 for the thin film, and 1.50 for the bottom material. The film thickness is 5.02 x 10-7 m.
(a) Of the visible wavelengths (400 to 700 nm) that result in fully constructive interference at an observer above the film, which is the longer wavelength?
(b) Which is the shorter wavelength?