  In the last decades unprecedented progress in the manipulation of spin
angular momentum (SAM) and orbital angular momentum (OAM) of light has been
achieved, enabling a number of applications ranging from classical and quantum
communication, to optical microscopy and super-resolution imaging. Metasurfaces
are artificially engineered 2D metamaterials with designed subwavelength-size
building blocks, which allow precise control of optical fields with
unparalleled flexibility and performance. The reduced dimensionality of optical
metasurfaces enables new physics and leads to functionalities and applications
that are remarkably different from those achievable with bulk materials. In
this review, we present an overview of the progress in optical metasurfaces for
manipultation of SAM and OAM of light, for applications in integrated
spin-orbit conversion (SOC) devices.
