1. Physics 52 - Heat and Optics Dr. Joseph F. Becker Physics Department San Jose State University © 2003 J. F. Becker

2. Chapter 38 Diffraction

3. Fig. 38-1 Geometric optics predicts that a straight edge should give a shadow with a sharp boundary.

4. Fig. 38-4 (a) Geometric shadow of a horizontal slit. (b) Diffraction pattern of a horizontal slit actually observed.

5. Fig. 38-5 Diffraction be a single rectangular (horizontal) slit. (a) Huygen’s Principle. (b) Fresnel (near field) diffraction. (c) Fraunhofer diffraction. (d) Use of a converging lens to get Fraunhofer diffraction.

6. Fig. 38-6 (a) Side view of a horizontal slit of width a. (b) Enlarged view of half the slit. The ray from the middle of the slit travels a distance a/2 sin  farther to the point P than does the ray from the top edge of the slit.