Od-4 Diffraction (Fresnel)

Aim

To demonstrate the diffraction pattern of various objects subject to the Fresnel conditions (near field diffraction).

Apparatus

  • Laser
  • Optical bench
  • Spatial filter
  • Collimator
  • Ground glass screen
  • Video camera and monitor

Fresnel Diffraction 1 Fresnel Diffraction 4

Fresnel Diffraction 2 Fresnel Diffraction 3

Fresnel Diffraction Diagram

Fresnel Diffraction Setup, Patterns and Diagram.

Description

When the source or the image plane are too near the diffracting object for the curvature of the wavefronts to be negligible Fresnel diffraction prevails. The experimental setup above produces these conditions. Diffracting objects are placed at O.