Tunable two-photon quantum interference of structured light

Abstract

Structured photons are nowadays an interesting resource in classical and quantum optics due to the richness of properties they show under propagation, focusing and in their interaction with matter. Vectorial modes of light in particular, a class of modes where the polarization varies across the beam profile, have already been used in several areas ranging from microscopy to quantum information. One of the key ingredients needed to exploit the full potential of complex light in quantum domain is the control of quantum interference, a crucial resource in fields like quantum communication, sensing and metrology. Here we report a tunable photon-photon interference between vectorial modes of light. We demonstrate how a properly designed spin-orbit device can be used to control quantum interference between vectorial modes of light by simply adjusting the device parameters and no need of interferometric setups. We believe our result can find applications in fundamental research and quantum technologies based on structured light by providing a new tool to control quantum interference in a compact, efficient and robust way.

Experimental implementation of fully controlled dephasing dynamics and synthetic spectral densities

“…Moreover, it is also possible to include coherent operations to the existing set-up allowing for the exploitation of the combination of sequences of coherent operations and controllable decoherent operations, in a many-body scenario, for quantum control and simulation purposes (see also [6,7]). Lastly, activities using structured light have increased significantly during the recent years [32] including also photonic experiments [33]. Here, our results open the possibility to combine interferometry with fully con-trollable noise and structured photons.…”

Vectorial light-matter interaction -- exploring spatially structured complex light fields

“…70 The flexibility of this approach has recently been beautifully demonstrated by generating tunable two-photon quantum interference of vector light, measured by observing the Hong-Ou-Mandel dip. 71 Atoms are not naturally anisotropic, but they can become polarization sensitive in external fields, most notably by magneto-optical effects and by optical pumping in strong probe light. These effects are well understood and utilised in atomic magnetometry [72][73][74][75] and polarization selective absorption spectroscopy.…”