Time-to-space ghost imaging

Temporal ghost imaging is based on the temporal correlations of two optical beams and aims at forming a temporal image of a temporal object with a resolution, fundamentally limited by the photodetector resolution time and reaching 55 ps in a recent experiment. For further improvement of the temporal resolution, it is suggested to form a spatial ghost image of a temporal object relying on strong temporal-spatial correlations of two optical beams. Such correlations are known to exist between two entangled beams generated in type-I parametric downconversion. It is shown that a sub-picosecond-scale temporal resolution is accessible with a realistic source of entangled photons.