PURPOSE: To demonstrate laser diffraction by opaque discs.
DESCRIPTION: A set of opaque discs is mounted on a slides which can be moved across the laser beam on a cross-carriage. Two sets of opaque discs are available: (1) 0.25mm, 0.50mm, and 1.00mm, and (2) 0.50mm, 1.00mm, and 1.50mm. The smaller discs allow more laser light to pass around them and therefore produce a brighter pattern. The pattern can generally be seen in the lecture hall without aid of a magnifying lens by backing the cart as far as possible away from the screen in front of the hall. For display on the small screen on the cart optical rail a spherical lens can be used if necessary.
REFERENCES: (PIRA 6C20.30)
EQUIPMENT: Laser cart with mounted opaque discs.
SETUP TIME: None.
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