Antireflection coatings can be used on the inner surfaces of

Antireflection coatings can be used on the inner surfaces of eyeglasses to reduce the reflection of stray light into the eye. This reduces eyestrain. If the index of refraction of the coating is 1.38, what thickness should the coating lie ho as to be most effective at 480 nm? Find the thinnest possible coating.

Solution

index of refraction of coating, n = 1.38 and wavelength, = 480nm

thus, the thicness of the coating is,

                t = /4n = 480 /4*1.38 = 86.9 nm