Diffraction at an edge

Principle

When a narrow pencil of light strikes the edge of an obstacle, it undergoes partial diffraction. The diffracted section is superposed on the light passing the edge and, due to the coherence of the two sections of light, interference occurs in the border area between light and shadow behind the edge.

Benefits

• Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench
• Extension with others sets at anytime, no additional light sources needed, recognition value for students

Tasks

Is a sharply outlined shadow created when light is incident upon the edge of a wide obstacle? Direct a narrow pencil of light onto the edge of an obstacle (half-plane) so that some of the light shines past the edge, and investigate the border area between light and shadow behind the obstacle.