title: Metasurfaces for general transformations of electromagnetic fields.
abstract: In this review paper I discuss electrically thin composite layers, designed to perform desired operations on applied electromagnetic fields. Starting from a historical overview and based on a general classification of metasurfaces, I give an overview of possible functionalities of the most general linear metasurfaces. The review is concluded with a short research outlook discussion.
authors.affiliation: Department of Radio Science and Engineering, Aalto University, Aalto 00076, Finland sergei.tretyakov@aalto.fi.
authors.forename: S A
authors.initials: SA
authors.lastname: Tretyakov
keywords: metasurface; reflection; transmission