Quantum ghost imaging of a transparent polarisation sensitive phase pattern

Abstract

A transparent polarisation sensitive phase pattern exhibits a position and polarisation dependent phase shift of transmitted light and it represents a unitary transformation. A quantum ghost image of this pattern is produced with hyper-entangled photons consisting of Einstein-Podolsky-Rosen (EPR) and polarisation entanglement. In quantum ghost imaging, a single photon interacts with the pattern and is detected by a stationary detector and a non-interacting photon is imaged on a coincidence camera. EPR entanglement manifests spatial correlations between an object plane and a ghost image plane, whereas a polarisation dependent phase shift exhibited by the pattern is detected with polarisation entanglement. In this quantum ghost imaging, the which-position-polarisation information of a photon interacting with the pattern is not present in the experiment. A quantum ghost image is constructed by measuring correlations of the polarisation-momentum of an interacting photon with polarisation-position of a non-interacting photon. The experiment is performed with a coincidence single photon detection camera, where a non-interacting photon travels a long optical path length of 17.83 m from source to camera and a pattern is positioned at an optical distance of 19.16 m from the camera.

Quantum imaging of biological organisms through spatial and polarization entanglement

“…In contrast, other techniques distribute the spatial modes of SPDC beams across multipixel cameras, yielding fewer spatial modes per pixel and lower SNRs. Compared with existing quantum birefringence imaging techniques that provide either polarizationsensitive coincidence counts (38)(39)(40)(41) or birefringence phase retardation images (10,42,43), ICE's ghost birefringence quantification offers full birefringence properties, including not only the birefringence phase retardation but also the principal refractive index axis angle, both of which are important for biomedical imaging (fig. S17).…”

“…6B), and the phase retardation between the two refractive index axes (Fig. 6C) of the zebrafish, providing full birefringence properties that are biologically relevant but have not been obtained with existing quantum imaging techniques (10,(38)(39)(40)(41)(42)(43). Furthermore, because of polarization entanglement, measuring the idler photon's polarization state instantly determines the incident signal photons, thus allowing instant quantification of the object's full birefringence properties, regardless of its distance.…”

“…Therefore, they are unsuitable for practical biological studies, which often demand systematic investigation of multiple parts in a biological system with an FOV across a whole organism. Last, while existing quantum imaging techniques have the capacity to measure transmittance (absorption) and birefringence phase retardation, the comprehensive quantification of birefringence properties through quantum imaging remains unachieved (10,(38)(39)(40)(41)(42)(43).…”