An optical company coats a glass lens (nglass=1.52) with a single layer of magnesium fluoride (nMgF2=1.38) to reduce reflections of green light (λ0=550nm in air). Light strikes the lens at 25∘ from the normal in air.
(a) Determine the internal angle in the MgF2 layer.
(b) Calculate the minimum coating thickness that minimizes reflection of λ0=550nm light.