A coating of MgF2 (n = 1.38) is deposited on a glass plate (n = 1.50). Light is incident (from air)
onto the plate at angle 60¡ã degrees from the normal to the surface. (Note that this is not nearnormal
incidence and you will have to adjust the equations to allow for the angle)
What is the thinnest MgF2 coating that will minimise reflection of the light at a wavelength
(in air) of 500 nm?