Quantum microscopy based on Hong–Ou–Mandel interference

Hong–Ou–Mandel (HOM) interference—the bunching of indistinguishable photons at a beamsplitter—is staple quantum optics and lies the heart many sensing approaches recent optical computers. Here we report full-field, scan-free imaging technique that exploits HOM interference to reconstruct surface depth profile transparent samples. We demonstrate ability retrieve images with micrometre-scale features photon flux as small seven pairs per frame. Using single-photon avalanche diode camera, measure both bunched anti-bunched photon-pair distributions output an interferometer, which are combined provide lower-noise image sample. This approach demonstrates possibility microscopy tool for label-free samples in very low regime. enables depth-resolved light levels.