Spectrally-resolved Hong-Ou-Mandel interferometry for Quantum-Optical Coherence Tomography

Abstract: In this paper, we revisit the well-known Hong-Ou-Mandel (HOM) effect in which two photons, which meet at a beamsplitter, can interfere destructively, leading to null in coincidence counts. In a standard HOM measurement, the coincidence counts across the two output ports of the beamsplitter are monitored as the temporal delay between the two photons prior to the beamsplitter is varied, resulting in the well-known HOM dip. We show, both theoretically and experimentally, that by leaving the delay fixed at a particular value while relying on spectrally-resolved coincidence photon-counting, we can reconstruct the HOM dip, which would have been obtained through a standard delay-scanning, non-spectrally-resolved HOM measurement. We show that our numerical reconstruction procedure exhibits a novel dispersion cancellation effects, to all orders. We discuss how our present work can lead to a drastic reduction in the time required to acquire a HOM interferogram, and specifically discuss how this could be of particular importance for the implementation of efficient quantum-optical coherence tomography devices.