  Rapid progress in the development of metasurfaces allowed to replace bulky
optical assemblies with thin nanostructured films, often called metasurfaces,
opening a broad range of novel and superior applications to the generation,
manipulation, and detection of light in classical optics. Recently, these
developments started making a headway in quantum photonics, where novel
opportunities arose for the control of nonclassical nature of light, including
photon statistics, quantum state superposition, quantum entanglement, and
single-photon detection. In this Perspective, we review recent progress in the
field of quantum-photonics applications of metasurfaces, focusing on innovative
and promising approaches to create, manipulate, and detect nonclassical light.
