Question

Plane coherent light waves with wavelength 565 nm are incident on two narrow parallel slits positioned a distance d = 1 mm apart in a plane parallel to the incoming wavefronts. The interference pattern is observed on a screen parallel to the original wavefronts at 1 m from the two slits.

One of the slits is covered on the illuminated side by a glass slide of 0.1 mm thickness with refractive index 1.5.

a/ What is the phase difference ∆φ between light waves emerging from one slit compared to light waves emerging from the other slit? Give the phase difference in radians in the range 0 ≤ ∆φ ≤ 2π. [5 pts] [Hint: For one slit the light must travel through 0.1 mm of glass, whereas for the other slit the light must travel through 0.1 mm of air instead.]

Answer 1