Position-correlated biphoton wavefront sensing for quantum adaptive imaging

Quantum imaging with spatially entangled photons offers advantages such as enhanced spatial resolution, robustness against noise, and counter-intuitive phenomena. In quantum adaptive optics, biphoton spatial aberration correction has been achieved by using classical beams to detect the aberration source or scanning the correction phase on biphotons when the source is unreachable. Here, a new method named position-correlated biphoton Shack-Hartmann wavefront sensing is introduced, where the phase pattern added on photon pairs with a strong position correlation is reconstructed from their position centroid distribution at the back focal plane of a microlens array. Experimentally, biphoton phase measurement and adaptive imaging against the disturbance of a plastic film are demonstrated. This single-shot method is a more direct and efficient approach to biphoton phase measurement, suitable for integration into quantum microscopy, remote imaging, and communication.