Principle

If circular apertures are illuminated with coherent light, concentric bright and dark circles alternate behind them due to diffraction and interference. The intensity of the interference maxima decreases rapidly with increasing distance from the center.If the circular apertures are exchanged for circular apertures, similar interference patterns appear. Brightness is always observed at any location on the center axis of the geometric shadow area.

Benefits

• Curriculum-relevant DEMO Experiment in optics
• Equivalence to the corresponding student experiment
• Stable optical bench
• Compact, simple construction

Tasks

• Diffraction at circular apertures and circular apertures - Poisson's spot