Yu.S. Kivshara,b aSt. Petersburg National Research University of Information Technologies, Mechanics and Optics, ul. Sablinskaya 14, St. Petersburg, 197101, Russian Federation bNonlinear Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, Mlls Road, Bldng 59, Canberra, 0200, Australia cSchool of Electrical Engineering, Aalto University, PO Box 11000, Aalto, FI-00076, Finland
The review is devoted to one of the most rapidly developing area of modern optics — optical nanoantennas. Been formulated a general concept of optical nanoantennas and main characteristics that are relevant to this science direction. Accordingly to our classification two main groups of nanoantennas — metal and dielectric (including semiconductors) — are defined. For both groups a literature review is performed. An overview of non-linear optical nanoantennas is provides. Main practical application of nanoantennas and their perspectives are discussed.