Single-Photon-Level Nonlinear Optics Through Quantum Interference
Jeff S. Lundeen, K. J. Resch, Aephraim M. Steinberg · Optical Fiber Communication Conference and International Conference on Quantum Information · 2001
We demonstrate suppression of spontaneous parametric down-conversion via quantum interference with two weak coherent states. Pairs of photons upconvert with high efficiency exhibiting a nonlinearity enhanced by 10 orders of magnitude. This constitutes a two-photon switch.