Time-resolved polarization decoherence in metal hole arrays with correlated photons

We study the combined polarization decoherence experienced by entangled photons due to time- and space-related dephasing processes in a metal hole array. These processes are implemented when the entangled photons are sent through a birefringent delay and are focused on the array. In particular, we demonstrate that compensating the temporal separation of the two polarizations after passage through the array can only partly recover the original coherence. This, surprisingly, shows a coupling between the temporal and spatial decoherence channels; we ascribe this coupling to transverse propagation of surface plasmons. (c) 2006 Optical Society of America.