All-purpose spatial correlations in holographic thermal light

Two landmark photon correlation effects, the Einstein-Podolsky-Rosen (EPR) correlation in a quantum entangled source and the Hanbury-Brown-Twiss (HBT) correlation in a thermal light source, have long attracted great attention from the physics community. Here, we report the experimental generation of an all-purpose photon-correlation source called holographic thermal light, including both HBT-type and EPR-like correlations, with thermal photons over a wide spectral range (from UV to IR) and a typical polarization combination. All two-photon correlations are established in the framework of linear optics. Interestingly, the topological structures of the diffraction patterns of the sources are very similar to those in type-I and type-II spontaneous parametric down-conversion (SPDC) processes. Holographic thermal light with multiple degrees of freedom will establish a quantum-inspired, high-brightness, low-cost classical demonstration platform capable of facilitating various quantum imaging applications at the single-photon level.