An intuitive introduction to the concept of spatial coherence
  The concept of spatial coherence is usually hard to be understood the first time that it is studied. We propose here a fully intuitive geometric description that does not contain mathematical difficulties and permits to understand how a Young Fringes system is obtained with a source not spatially coherent. It is based in a very simple experiment that permits the detection of spatial coherence in a scene. Experimental results are shown. 
H\'ector Rabal, Nelly L. Cap, Eduardo Grumel, Marcelo Trivi
physics.optics physics.ed-ph