Direct observation of photon pairs at a single output port of a beam-splitter interferometer

Giovanni Di Giuseppe,* Mete Atatüre, Matthew D. Shaw, Alexander V. Sergienko, Bahaa E. A. Saleh, Malvin C. Teich, Aaron J. Miller, Sae Woo Nam, and John Martinis Department of Electrical & Computer Engineering, Quantum Imaging Laboratory, Boston University, 8 Saint Mary’s Street, Boston, Massachusetts 02215, USA Department of Physics, Quantum Imaging Laboratory, Boston University, 8 Saint Mary’s Street, Boston, Massachusetts 02215, USA National Institute of Standards and Technology, Mail Code 814, 325 Broadway, Boulder, Colorado 80395, USA ~Received 22 May 2003; published 16 December 2003!