Incoherent Coincidence Imaging and Its Applicability in X-ray Diffraction

Entangled-photon coincidence imaging is a method to nonlocally image an object by transmitting a pair of entangled photons through the object and a reference optical system, respectively. The image of the object can be extracted from the coincidence rate of these two photons. From a classical perspective, the image is proportional to the fourth-order correlation function of the wave field. Using classical statistical optics, we study a particular aspect of coincidence imaging with incoherent sources. As an application, we give a proposal to realize lensless Fourier-transform imaging, and discuss its applicability in x-ray diffraction.

Figure 1

A setup of entangled-photon coincidence imaging. The source $S$ emits pairs of entangled photons. One of the photons transmits through the test system $h_t(x,x_t)$ which contains an unknown object, and the other photon transmits through a known reference system $h_r(x,x_r)$. Two detectors $D_t$ and $D_r$ record the intensity distribution. The coincidence rate $G^{(2,2)}(x_r,x_t)$ is measured to give an image of the object.