2002/02/28 by Pieter Kok, Hwang Lee, Jonathan P. Dowling · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.66.063814
published as Phys. Rev. A, Vol. 66, 063814 (2002) · 9 pages, 7 figures, REVTeX
arxiv created 2003/01/23 · arxiv updated 2009/12/01
Optical quantum nondemolition devices can provide essential tools for quantum information processing. Here, we describe several optical interferometers that signal the presence of a single photon in a particular input state without destroying it. We discuss both entanglement-assisted and non-entanglement-assisted interferometers, with ideal and realistic detectors. We found that existing detectors with 88% quantum efficiency and single-photon resolution can yield output fidelities of up to 89%, depending on the input state. Furthermore, we construct expanded protocols to perform QND detections of single photons that leave the polarization invariant. For detectors with 88% efficiency we found polarization-preserving output fidelities of up to 98.5%.