Chapter 38: Diffraction

Diffraction is the result of interference when a wave passes through an opening or edge.  Diffraction effects are easier or harder to see depending on the wavelength of the wave and the size of a given opening.  The physical principle behind diffraction is the same as that of interference (see Chapter 37): the superposition of waves.  In order to observe the effects of diffraction, slits or gratings must be of a size comparable to the wavelength of the light.

Table of Contents

Illustrations

• Illustration 38.1: Single Slit Diffraction.
• Illustration 38.2: Application of Diffraction Gratings.

Explorations

• Exploration 38.1: Modeling Diffraction from a Slit.
• Exploration 38.2: Diffraction Grating.

Problems

• Problem 38.1: Rank waves in ripple tanks by slit width.
• Problem 38.2: Rank waves in ripple tanks by slit width.
• Problem 38.3: Determine the slit width.
• Problem 38.4: Wavelength of light through a single slit.
• Problem 38.5: Wavelength of light through a diffraction grating.
• Problem 38.6: Number of slits per millimeter in diffraction grating.