M-ary-state phase-shift-keying discrimination below the homodyne limit

F. E. Becerra,1,* J. Fan,1 G. Baumgartner,2 S. V. Polyakov,1 J. Goldhar,3 J. T. Kosloski,4 and A. Migdall1 1Joint Quantum Institute, Department of Physics, University of Maryland, and National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA 2Laboratory for Telecommunications Sciences, 8080 Greenmead Drive, College Park, Maryland 20740, USA 3Department of Electrical and Computer Engineering, 2410 A.V. Williams Building, University of Maryland, College Park, Maryland 20742, USA 4Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA (Received 1 September 2011; published 22 December 2011)