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

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.