Efficient single photon emission mediated by quantum plasmonic metasurfaces (Invited Paper)

The generation of quantum light based on the nondeterministic process of spontaneous parametric down-conversion (SPDC) is usually performed by using bulky conventional nonlinear crystals and waveguides. However, these structures require strict momentum conservation for the involved photons, which strongly limits the versatility of the single photon emission they produce. In addition, the entangled state emission can only be obtained with a certain probability that is usually very small due to the inherent extremely weak nature of nonlinear optical processes. Quantum optical metasurfaces help to overcome these constraints due to their subwavelength thickness leading to relaxed momentum conservation (or phase-matching) requirements and increased optical nonlinear efficiencies. In our talk, we demonstrate compact quantum plasmonic metasurfaces to efficiently generate entangled and correlated single-photon pairs with unprecedently high SPDC generation rates.