The diffraction patterns in case of light sources of finite extension have been investigated. Depending on the size of the light source the edges of a slit are illuminated by either coherent or incoherent or partially coherent beams. Considering that according to the YoungRubinovicz theory the diffraction pattern is produced by secondary waves emerging from the edges of the slit and interfering with each other as well as with the incident waves, it is shown that depending on the degree of coherence, the interference fringes of the diffraction pattern show more or less contrast. The places of the maxima except for the main peak, also depend on the size of the light source. In order to verify the theory the calculated curves were compared with those obtained in the experiments and a good quantitative agreement was found.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Astronomy and Astrophysics