Figure 28-1Constructive and Destructive Interference

Figure 28-17Diffraction of Water Waves

Diffraction: the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge.

Figure 28-4Huygens’s Principle

Figure 28-2Two Radio Antennas Transmitting the Same Signal

2 1

2 1

constructive interference

1 destructive interference

2

m

m

Figure 28-3Young’s Two-Slit Experiment

Figure 28-5Path Difference in the Two-Slit

Experiment

sin m=0, 1, 2, 3...

1sin m=0, 1, 2, 3...

2

Condition for bright fringes

d m

Condition for dark fringes

d m

Figure 28-6The Two-Slit Pattern

Figure 28-18Single-Slit Diffraction

Figure 28-19Locating the First Dark Fringe in Single-Slit Diffraction

Figure 28-20Locating the Second Dark

Fringe in Single-Slit Diffraction

Condition for dark fringe

sin m= 1, 2, 3...

W m

Figure 28-26Path-Length Difference in a Diffraction Grating

For a diffraction grating

sin m=0, 1, 2, 3...

Condition for bright fringes

d m