Question:9 A thin film of refractive index 1.Five is illuminated with light of wavelength 600 m. If the film thickness is a hundred and fifty nm, what's the phase distinction between he light contemplated from the top and bottom surfaces? Question:10 A laser emits light with a wavelength of 633 nm. If a diffraction grating produces a 3rd-order maximum at an perspective of forty five ranges, what's the slit spacing of the grating?