Nonlinear interferometry via Fock-state projection.

G Khoury, H S Eisenberg, E J S Fonseca, D Bouwmeester
Author Information
  1. G Khoury: Department of Physics, University of California, Santa Barbara, California 93106, USA. khoury@physics.ucsb.edu

Abstract

We use a photon-number-resolving detector to monitor the photon-number distribution of the output of an interferometer, as a function of phase delay. As inputs we use coherent states with mean photon number up to seven. The postselection of a specific Fock (photon-number) state effectively induces high-order optical nonlinearities. Following a scheme by Bentley and Boyd [Opt. Express 12, 5735 (2004).10.1364/OPEX.12.005735], we explore this effect to demonstrate interference patterns a factor of 5 smaller than the Rayleigh limit.