SPONTANEOUS PARAMETRIC DOWN-CONVERSION FOR AN ARBITRARY MONOCHROMATICPUMP BEAM

Signal-idler photon-pairs generated in spontaneous parametric down-con version are considered for the case of an arbitrary monochromatic pump beam. It is shown that the quantum correlations between the signal an d idler photons allow them to be mirror images of each other. A simple and very intuitive imaging formula is derived to describe this effect . In contrast to a conventional mirror, the down-conversion crystal ac ts as a volume reflector whose characteristics can be controlled by th e spatial profile of the pump beam. For a very narrow pump beam the si gnal-idler photon-pairs suffer an effective aperture effect that reduc es their momentum correlations in a prescribed manner. (C) 1998 Elsevi er Science B.V. All rights reserved.