Diffraction and Interference Combined. Consider the interference pattern produced by two parallel slits of width a and separation d, in which d = 3a. The slits are illuminated by normally incident light of wavelength λ.
(a) First we ignore diffraction effects due to the slit width. At what angles θ from the central maximum will the next four maxima in the two-slit interference pattern occur? Your answer will be in terms of d and λ.
(b) Now we include the effects of diffraction. If the intensity at θ = 0 is I0, what is the intensity at each of the angles in part (a)?
(c) Which double-slit interference rnaxima are missing in the pattern?
(d) Compare your results to those illustrated in Fig. 36.12c. In what ways is your result different?