Abstract

The coherence properties of spontaneous parametric downconverted light are governed by the energy and phase-matching conditions. Ideally, this implies a strict one- to-one correspondence between each direction (signal) and a matching direction (idler). In the type-I configuration the light takes the form of concentric rings and is monochromatic everywhere, but the frequency varies with the polar angle. It is spatially incoherent, but the coherence time is infinite.

© 1995 Optical Society of America