Spectrally resolved Hong-Ou-Mandel interferometry for quantum-optical coherence tomography

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 be-tween 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 effect,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 fficient quantum optical coherence tomog-raphy devices.

Experimental demonstration of full-field quantum optical coherence tomography

We present,to the best of our knowledge,the first implementation of full-field quantum optical coherence tomography(FF-QOCT).In our system,we are able to obtain full three-dimensional(3D)information about the internal structure of a sample under study by relying on transversely resolved Hong–Ou–Mandel(HOM)interferometry with the help of an intensified CCD(ICCD)camera.Our system requires a single axial scan,obtaining full-field transverse single-photon intensity in coincidence with the detection of the sibling photon for each value of the signal-idler temporal delay.We believe that this capability constitutes a significant step forward toward the implementation of QOCT as a practical biomedical imaging technique.