Thermal light two-photon imaging: magic mirrors

Abstract

We show an experimental study of two-photon imaging using thermal light sources. It is interesting to see that the thermal source behaves like a mirror producing an equal size reproduction of a chosen object. We refer to such mirror as "magic" because the ghost image produced by the mirror is real in the sense that it lies in the real space and can be further imaged by a camera or an equivalent optical system. We also show that it is possible to overcome the main limitation towards the actual implementation of thermal light two-photon imaging, i.e. the poor contrast of the imaging pattern, by designing an appropriate correlation measurement scheme that is insensitive to the uncorrelated background noise.