Diffraction and Interference Double Slit Diffraction Diffraction is
Diffraction and Interference
Double Slit Diffraction • Diffraction is the bending of waves around barriers • English Physicist Thomas Young discovered that light bends around barriers as a wave. • Using the double slit experiment and monochromatic light, Young found evidence for the “wavenature” of light
Double Slit Diffraction • Interference fringes are the dark and bright bands created by the double slit experiment. • Dark bands are where the light is “out of phase”, cancelling each other out • Light bands are where the light is “in phase”, adding to each other
Double Slit Diffraction • Demo first, then lets draw a picture of the set up to derive the wavelength of light using the double slit pattern
Double Slit Diffraction • Example 1: pg 395: Red light falls on two narrow slits 0. 0190 mm apart. A first-order bright line is 21. 1 mm from the central bright line on a screen 0. 600 m from the slits. What is the wavelength of the red light?
Single Slit Diffraction •
Diffraction • There are two ways to break up white light into colors: diffraction and reflection. • Diffraction gratings have multiple slits that are able to break up a white light source into multiple colors. • The instrument used to measure light wavelengths with a diffraction grating is called a grating spectrometer
Diffraction • Watch a video • Do the worksheet • Homework: DUE 3/17 pg 395: 1, 2 and pg 398: 5, 7
- Slides: 8