Purpose: To demonstrate single- and multiple-slit interference/diffraction patterns in two or three dimensions.

*Demonstration currently not available

If you need this demo sooner rather than later let me know and I'll move its priority up.

1. Two dimensional patterns: Display single and multiple slit patterns on a screen placed several meters from slits.
2. Three dimensional patterns: Place the laser and slits in the rear of the classroom and the mirror and smoke-filled box in front. Aim the beam over the heads of the students so that it strikes the mirror and reflects downward through the smoke box at an angle below the line of sight of class members. (The mirror is needed to allow placement of the box several meters from the slits and the class to view the pattern from near the forward beam direction. The back-scattered light is not intense enough to be seen clearly.) The class can see distinct three-dimensional beams in the smoke-filled region. The photograph below is a sample 4-slit pattern. The table can be rotated about an axis through the center of the mirror so that viewers near the sides of the classroom can see the pattern. In both parts 1 and 2, the observed pattern can be compared quantitatively with theoretical predictions.

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