Sub-Rayleigh Quantum Imaging Using Single Photon Sources
  We propose a technique capable of imaging a distinct physical object with sub-Rayleigh resolution in an ordinary far-field imaging setup using single-photon sources and linear optical tools only. We exemplify our method for the case of a rectangular aperture and two or four single-photon emitters obtaining a resolution enhanced by a factor of two or four, respectively. 
C. Thiel, T. Bastin, J. von Zanthier, G. S. Agarwal