Beyond the diffraction limit via optical amplification
  In a previous article we suggested a method to overcome the diffraction limit behind a telescope. We refer to theory and recent numerical simulations, and test whether it is indeed possible to use photon amplification to enhance the angular resolution of a telescope or a microscope beyond the diffraction limit. An essential addition is the proposal to select events with above-average ratio of stimulated to spontaneous photons. We find that the diffraction limit of a telescope is surpassed by a factor ten for an amplifier gain of 200, if the analysis is restricted to a tenth of the incoming astronomical photons. A gain of 70 is sufficient with a hundredth of the photons. 
Aglae N. Kellerer, Erez N. Ribak
astro-ph.IM physics.optics