Demonstration of van Cittert-Zernike Theorem

Young's double-slit experiment was carried out with a spatially extended, partially coherent source. In this document, we use the Multiple Light Source to set up the extended source so that the disturbances at the slits are a mixture of incoherent and coherent radiation, and the vibrations are therefore partially correlated. The characteristic blurred interference fringe is obtained, and the van Cittert-Zernike theorem, which studies how the complex degree of coherence varies with propagation distance, is demonstrated.