Announcements 3/19/12 Prayer Office hours: next two weeks only 3-3:30 pm MWF There are substantial typos in problem P10.2. a. a.In the equation in part (c), the first two “phi”s should be “theta”s. b. b.In the sentence on the next page, it should say “Describe how this wave behaves as a function of r and theta”. (Also: you don’t have to give a detailed description of how it varies with r and theta, just a couple of general observations.) Please make the changes right now in your books.

Daily Comic In the Bleachers

Reading Quiz is called the __________ equation: a. a.Arago b. b.Fraunhofer c. c.Fresnel d. d.Helmholtz e. e.Kirchhoff

Reading Quiz Huygen’s principle involves: a. a.convolutions b. b.paraxial light c. c.ray methods d. d.wavelets

Reading Quiz Babinet’s principle relies on: a. a.calculus of variations b. b.linear superposition c. c.scalar approximation d. d.small angle approximation

Helmholtz equation vector vs. scalar

Goal: Huygens’ Principle r r R “Fresnel’s diffraction formula”

Deriving “Fresnel Approximation” formula

The Four Complicated Integral Formulas “The Fresnel approximation” “Fresnel’s diffraction formula” “The Fresnel-Kirchhoff diffraction formula” “The Fraunhofer approximation” (next time!) (10.13)  

HW problem P10.6, due Tues 3/27/12 Fresnel approx., with cylindrical symmetry x=0, y=0 Fraunhofer approx., with cylindrical symm. “Fresnel-Kirchoff”, but really just original Fresnel’s diffraction formula

Babinet’s Principle