Metasurface interferometry toward quantum sensors

摘要

Optical metasurfaces open new avenues for the precise wavefront control of light for integrated quantum technology.Here,we demonstrate a hybrid integrated quantum photonic system that is capable of entangling and disentangling two-photon spin states at a dielectric metasufface.Via the interference of single-photon pairs at a nanostructured dielectric metasurface,a path-entangled two-photon NOON state with circular polarization that exhibits a quantum HOM interference visibility of 86 ± 4％ is generated.Furthermore,we demonstrate nonclassicality andphase sensitivity in a metasurface-based interferometer with a fringe visibility of 86.8 ± 1.1％ in the coincidence counts.This high visibility proves the metasurface-induced path entanglement inside the interferometer.Our findings provide a promising way to develop hybrid-integrated quantum technology operating in the high-dimensional mode space in various applications,such as imaging,sensing,and computing.