Ghost imaging: from quantum to classical to computational

Ghost-imaging experiments correlate the outputs from two photodetectors: a high spatial-resolution (scanning pinhole or CCD 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 review the Gaussian-state framework for ghost imaging setups that rely on biphoton states or pseudothermal states. The understanding derived therefrom leads to two new ghost imaging configurations, employing spatial light modulators to impose controlled spatial incoherence at the source, one of which uses only a single-pixel detector.