The influence of atmospheric turbulence on holographic ghost imaging using orbital angular momentum entanglement: Simulation and experimental studies

The holographic ghost imaging is a novel ghost imaging scheme, where orbital angular momentum (OAM) entanglement is used to encode object information. OAM state is associated with the spatial distribution of the wave-functions. Hence, atmosphere turbulence (AT), in principle, will reduce the corresponding image resolutions. In this paper, we quantitatively investigate the influences of AT on such imaging scheme with a two-gray-scale and a eight-gray-scale phase object by both numerical simulations and experiments, where the AT-induced phase perturbations are introduced by simulated random phase screens inserting propagation paths. The numerical simulation and experimental results show that with the increase of the constant of index refraction, the peak signal-to-noise ratio (PSNR) of the reconstructed image goes down quickly. For a two-gray-scale ‘NUPT’ character, PSNR degrades from 102 at An2=1×10−16m−2/3 weak turbulence to 20 at An2=1×10−12m−2/3 strong turbulence by simulations, while the PSNR decreases from 20 at An2=1×10−16m−2/3 to 12 at An2=1×10−12m−2/3 by experiment. When the object is turned to eight-gray-scale ‘Lena’ image, the PSNR values show that AT has the degraded effects on HGI, even at An2=5×10−16m−2/3 weak turbulence. All these results show that the holographic ghost imaging is influenced by atmospheric turbulence, the methods to mitigate the influence should be developed in the implementation of ghost imaging using OAM states.