Polychromatic 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.