Od-3 Diffraction (Fraunhaufer)
Aim
To demonstrate the diffraction pattern of various objects subject to the Fraunhaufer conditions (far field diffraction).
Apparatus
- Laser
- Optical bench
- Spatial filter
- Collimator
- Ground glass screen
- Video camera and monitor
- Various objects
Fraunhaufer Diffraction Diagram.
Description
As long as both the incoming and outgoing waves approach being planar (differing therefrom by a small fraction of a wavelength over the extent of the diffracting object), we obtain Fraunhaufer diffraction. The experimental setup to achieve these conditions is displayed above. Diffracting objects are inserted after the collimator.