Fraunhofer & Fresnel diffraction in one-dimension

Fraunhofer diffraction is "far-field" diffraction from a single slit and from equally spaced multiple slits. The patterns observed can be interpreted in terms of the Fourier transform of an aperture function.

Fresnel Diffraction is "near-field" diffraction. We study the pattern from an adjustable-width slit and a half plane, and explore the transition from Fresnel diffraction to the Fraunhofer limit.

A linear photodetector array is used to acquire a digitized output of the light intensity in the diffraction patterns. This allows a quantitative comparison with the theory.

Experiment Information