HIgh-Noon States with High Flux of Photons Using coherent Beam   Stimulated Non-Collinear Parametric Down Conversion
  We show how to reach high fidelity NOON states with a high count rate inside optical interferometers. Recently it has been shown that by mixing squeezed and coherent light at a beamsplitter it is possible to generate NOON states of arbitrary N with a fidelity as high as 94%. (Afek I. et al. Science 328, 879 (2010)). The scheme is based on higher order interference between "quantum" down-converted light and "classical" coherent light. However, this requires optimizing the amplitude ratio of classical to quantum light thereby limiting the overall count rate for the interferometric super-resolution signal. We propose using coherent-beam-stimulated non-collinear down converted light as input to the interferometer. Our scheme is based on stimulation of non-collinear parametric down conversion by two-mode coherent light. We have somehow a better flexibility of choosing the amplitude ratio in generating NOON states. This enables super-resolution intensity exceeding the previous scheme by many orders of magnitude. Therefore we hope to improve the magnitude of N-fold super-resolution in quantum interferometry for arbitrary N by using bright light sources. We give some results for N=4 and 5. 
Aziz Kolkiran
quant-ph