max

Figure 37.4 (a) Constructive interference occurs at point P when the waves combine. (b) Constructive interference also occurs at point Q. (c) Destructive interference occurs at R when the two waves combine because the upper wave falls half a wavelength behind the lower wave. (All figures not to scale.) Fig 37-4, p.1179

Figure 38. 7 Fraunhofer diffraction pattern for a single slit Figure 38.7 Fraunhofer diffraction pattern for a single slit. The light intensity at a distant screen is the resultant of all the incremental electric field magnitudes from zones of width Dy. Fig 38-7, p.1210

Figure 38.10 (a) A plot of light intensity I versus b/2 for the single-slit Fraunhofer diffraction pattern. (b) Photograph of a single-slit Fraunhofer diffraction pattern. Fig 38-10, p.1212

Active Figure 38.11 The combined effects of two-slit and single-slit interference. This is the pattern produced when 650-nm light waves pass through two 3.0- mm slits that are 18 mm apart. Notice how the diffraction pattern acts as an “envelope” and controls the intensity of the regularly spaced interference maxima. Fig 38-11, p.1213

Resolved Angle?

Figure 38.13 Individual diffraction patterns of two point sources (solid curves) and the resultant patterns (dashed curves) for various angular separations of the sources. In each case, the dashed curve is the sum of the two solid curves. (a) The sources are far apart, and the patterns are well resolved. (b) The sources are closer together such that the angular separation just satisfies Rayleigh’s criterion, and the patterns are just resolved. (c) The sources are so close together that the patterns are not resolved. Fig 38-13, p.1215

Bragg’s Law

(a) When unpolarized light is incident on a reflecting surface, the reflected and refracted beams are partially polarized. (b) The reflected beam is completely polarized when the angle of incidence equals the polarizing angle qp, which satisfies the equation n tan qp. At this incident angle, the reflected and refracted rays are perpendicular to each other.

Let’s find out the thickness of the film… How come there are many color? Let’s find out the thickness of the film…

Newton’s Ring At the center: Destructive interference Why?