13.8. Shown in figure 13.39 are 4 diffraction patterns such as might be produced by shining laser light (nearly a plane wave) through a slit or slits, and projecting the pattern onto a photographic plate far away. The patterns are each produced by about 500 individual photons striking the plate with a probability density proportional to the intensity of the diffracted wave.
A:
B:
C:
D:
Figure 13.39: Four diffraction patterns.
The four objects that produced these patterns were, in a random order,
i. A single slit, 1 mm wide;
ii. A single slit, 0.6 mm wide;
iii. Two slits, each 0.6 mm wide, with centers 1.5 mm apart;
iv. Six slits, each 0.6 mm wide, with adjacent centers 1.5 mm apart.
a. Which is which?
b. How do you know?