Question

A thin film having refractive index` mu" = 1.5"` has air on both sides. It is illuminated by white light falling normally on it. Analysis of the reflected light shows that the wavelengths 450 nm and 540 nm are the only missing wavelengths in the visible portion of the spectrum. Assume that visible range is 400 nm to 780 nm.
(a) Find thickness of the film.
(b) Which wavelengths are brightest in the interference pattern of the reflected light?

Answer 1

Correct Answer - (a)900 nm (b)415nm ,491nm,600nm,771nm