Od-4 Diffraction (Fresnel)
Published: Wednesday 15 March 2006 - Updated: Monday 28 March 2011
To demonstrate the diffraction pattern of various objects subject to the Fresnel conditions (near field diffraction).
- Optical bench
- Spatial filter
- ground glass screen
- T.V. camera and monitor
Click on pictures to enlarge.
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.