This is an interesting idea:
http://physicsworld.com/cws/article/news/2014/apr/29/quantum-telescope-could-make-giant-mirrors-obsolete
However, I’m having a hard time figuring out how it is supposed to work. I understand the resolution limit of telescopes in classical terms: Given a wavefront that gets windowed by an aperture, you’ve cut out the longest wavelengths in the fourier transform of the wavefront passing through the apeture, or reflecting off the primary mirror which limits the spot size that it can focus down to at the focal plane.
The same sort of logic should apply to single photons. If you have a photon from a distant star, it’s spread out into a giant wavefront by the time it gets to your primary mirror, the portion of the photon that reflects of the primary mirror is windowed, and can only focus down to a spot of a finite size on your detector (which pixels/entangled superposition of pixels it ends up exciting then becomes a matter of $INTERPRETATION), but N such photons will light up some airy disc of finite size on your detector.
So if you pass the photons through a gain medium (such as for a laser) prior to them hitting your primary mirror, you get N photons with the same wavefront description as the classical case passing through your detector. I can understand why you would get a brighter image from this (more photon counts hitting the detector within the airy disc), but not why the image should have a finer resolution.
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