Chromatic ghost interference using supercontinuum pseudothermal light

Optical intensity correlation offers a promising pathway for achieving spatial interference and coherent diffraction using quasi-monochromatic incoherent radiation. However, the inherent ultrashort coherence time of broadband incoherent sources fundamentally restricts spectral-resolved capability in such correlation-based methodologies. Here, we overcome this limitation by engineering a supercontinuum pseudothermal light source, exhibiting pronounced spatial-spectral intensity correlations. This work endows Hanbury Brown–Twiss (HBT) intensity interferometer and ghost interference experiments with colors. To our best knowledge, we present the first experimental demonstration of multispectral ghost interference, yielding a polychromatic interference pattern via intensity correlation. Furthermore, nondegenerate ghost interference and novel non-local spectral filtering are well demonstrated. The proposed supercontinuum pseudothermal light shows promising spatial-spectral random encoding capabilities and is in good shape for diverse intensity correlation-aided applications, such as correlation hyperspectral imaging.