Young interferencial experiments with filamentary light sources

MANCEÑIDO, M.E., POZZI, G., ZUNINO, L., & GARAVAGLIA, M.

Delft, Holanda

Congreso; Fifth international Topical Meeting on Education and Training in Optics; 1997

International Commission for Optics (ICO)

The van Cittert-Zernike theorem allows interpreting the coherence distribution of an electromagnetic field from simple interferential experiments, like Young experiments. The visibility of the interferential fringes is equal to the modulus of the complex degree of coherence of the optical field. In the experiments commented in this communications, an electrical bulb linear carbon filament and the focal line of a cylindrical lens illuminated by a collimated expanded He-Ne red laser light, were both assumed to be filamentary light sources in order to observe Young interferential fringes with each of them. The electric lamp is a polychromatic light source, while the laser is a monochromatic one. When a filamentary light source is parallel to the Young slits, the interferential fringes are well defined and highly contrasted. If the source is rotated in a plane parallel to that of the slits, the visibility of the interferential fringes monotonically decreases and reaches zero in case of perpendicularity. Interferential fringes were photographically recorded and the color slides were electronically scanned and processed.