2 (30 points). A glass window with an index of refraction of 1.58 is to be coated with a cryolite

film (n = 1.30) to decrease the reflection of normally incident green light (500 nm). What should

be the minimal thickness of the film? What are the reflection coefficients without and with the

coating? You only need to consider two reflection beams from the front and back surfaces of the

cryolite film.