Problem 5.82

Diffused monochromatic light with wavelength \(\lambda=0.60 \mu \mathrm{m}\) falls on a thin film with refractive index \(n=1.5\). Determine the film thickness if the angular separation of neighbouring maxima observed in reflected light at the angles close to \(\theta=45^{\circ}\) to the normal is equal to \(\delta \theta=3.0^{\circ}\).