Off-Normal\nPolarized Single-Photon Emission with Anisotropic\nHolography Metasurfaces

Solid-state quantum emitters (QEs) with arbitrary direction\nemission\nand well-defined polarization are critical for scalable single-photon\nsources and quantum information processing. However, the design strategy\nfor on-chip generation of off-normal photon emission with high-purity\npolarization characteristics has so far remained elusive. Here, we\nintroduce the anisotropic holography metasurfaces for efficiently\nmanipulating the emission direction and polarization of QE. The proposed\nmethod offers a flexible way to realize phase matching in surface\nplasmon scattering with spatially varying filling factors and provides\nan efficient route for designing advanced QE-coupled metasurfaces.\nBy nonradiatively coupling nanodiamonds with metasurfaces, we experimentally\ndemonstrate on-chip generation of well-collimated single-photon emission\npropagating along off-normal directions (i.e., 20° and 30°)\nfeaturing a divergence angle lower than 2.5°. The experimental\naverage degree of linear polarization attains up to >0.98, thereby\nrevealing markedly high polarization purity. This study facilitates\napplications of QEs in the deployment of integrated quantum networks.