Now we have a camera lens with n = 1.50. We want to coat its surface with a thin film of magnesium fluoride (MgF2, n = 1.38), so that it hardly reflects any yellow-green light, which the human visual system is most sensitive to. Our goal is to find the smallest non-zero thickness (tmin) of the film that will produce completely destructive interference for the yellow-green light (λ= 550 nm in vacuum). Assume the light is traveling in air before encountering the film, and that the light strikes the film at normal incidence.

What is the minimum non-zero thickness of the coating that will produce destructive interference for the yellow-green light?

_______ nm

If the coating layer is t = 3/4⋅λ_film (λ_film is the wavelength of yellow-green light in the coating), what is the wavelength of the light that is enhanced among the reflected light and is within the range of visible spectrum (380-750 nm)?

_____nm