Towards super-resolution quantum astronomy

Heisenberg's uncertainty principle tells us that it's impossible to determine simultaneously the position of a photon crossing a telescope's aperture as well as the angle of its momentum. A new technique suggests to overcome the diffraction limit via optical amplification. A number of entangled photons, created by amplification of a single photon, behaves as a single quantum system with respect to the uncertainty principle. Unfortunately, spontaneous emission contributes noise and negates the possible gain from this stimulated emission. The spontaneous photons guarantee the uncertainty principle.

Thus the problem of low resolution is replaced by the problem of low SNR. The detection of spontaneous photons follows the same Poisson statistics in time and space. However, the stimulated photons are spatially and temporally coherent with the incoming photons. A pixel with additional hidden thermal signal will slightly modify the Poisson statistics, and only within the diffraction pattern of the photon packets.

We characterize the average number of spontaneous photons in all pixels, and subtract it from the stimulated photons. This algorithm is applied on simulated detection events of an amplified signal. The reconstructed image is resolved beyond the limit of the same optical system in the absence of amplification.

In the lab we produced a number of samples of a wide-band solid-state dye (DCM within PMMA), because the expected number of (stellar) photons is small, and a solid-state dye is easier to handle compared to a dye solution. Initial results with a white light source and a laser pump characterize the parameters of the method.