Bounds on entangled imaging

We present a detailed theoretical analysis of quantum imaging intended to reveal under what conditions it is superior to imaging with non-entangled photons in order to determine practical bounds on quantum imaging systems. Our analysis includes a description of the propagation and detection of entangled light signals taking into account attenuation, diffraction, and event statistics. Each of these three are significant roadblocks on the path towards practical quantum imaging and we rate how severe each of these is in three imaging regimes (exo-atmospheric, short distance endo-atmospheric, and long distance endo-atmospheric) and three detection regimes (high signal-to-background, low signal-to-background, and saturated). In an attempt to overcome these roadblocks we briefly speculate about the possible role of nonlinear propagation phenomena which may enable entangled light propagation without diffraction, and of X-waves, which may provide for the possibility of overcoming all of the above mentioned roadblocks.