Ghost imaging using homodyne detection

The homodyne detection, which can be used to get access to both modulus and phase information in ghost-imaging schemes based on parametric down-conversion (PDC) in the high-gain regime, was investigated. It was found that the signal-idler correlations contain the full amplitude and phase information about an object located in the signal path, both in the near-field and the far-field case. The near-field image resolution was inherently linked to the far-field bandwidth of the image and determined by the bandwidth of the source of the correlated beams. A spatial averaging technique which improves the imaging bandwidth of the far-field correlations as well as speeds up the convergence rate was also shown.