Point sources S1 and S2 radiate in phase at wavelength 400 nm and at the same amplitude. The sources are located on an x axis at x = 6.5μm and x = – 6.0μm, respectively.
(a) Determine the phase difference (in radians) at the origin between the radiation from 51 and the radiation from S2.
(b) Suppose a slab of transparent material with thickness 1.5μm and index of refraction n = 1.5 is placed between x = 0 and x = 1.5μm. What then is the phase difference (in radians) at the origin between the radiation from, S1 and the radiation from S2?