Computational ghost imaging

Ghost-imaging experiments correlate the outputs from two photodetectors: a high spatial-resolution (scanning pinhole or charge-coupled-device camera) detector that measures a field which has not interacted with the object to be imaged and a bucket (single-pixel) detector that collects a field that has interacted with the object. We describe a computational ghost-imaging arrangement that uses only a single-pixel detector. This configuration affords background-free imagery in the narrow-band limit and a three-dimensional sectioning capability. It clearly indicates the classical nature of ghost-image formation.