Ghost imaging with incoherent and partially coherent light radiation.

We theoretically study ghost imaging with incoherent and partially coherent light radiation by using classical optical coherence theory. A Gaussian thin lens equation is derived for the ghost image. The equation depends on both paths. The quality and visibility of the ghost image are influenced by the source's transverse size, coherence width, and object characteristics. The differences between ghost imaging formed with incoherent light radiation and with entangled photon pairs are discussed.