This book covers the current key challenges of the research in the area, including: exploiting new material platforms, fully extending the device operation into the nonlinear regime, adding re-configurability to the envisaged devices and proposing new modeling tools to help in conceiving new functionalities.

Costantino De Angelis received the Laurea Degree summa cum laude in Electronic Engineering and the Ph.D. in Telecommunications from the University of Padova, in 1989 and 1993, respectively. Since 1998 he has been at the University of Brescia where he is a Full Professor of Electromagnetic Fields. He is an OSA Fellow and has been responsible for several University research contracts in the last 20 years within Europe, United States of America, and Italy. His technical interests are in optical antennas and nanophotonics; he is author of over 150 peer-reviewed scientific journal articles.

Giuseppe Leo received his Laurea degree summa cum laude in Electronic Engineering at La Sapienza University (Rome) in 1990 and his Ph.D. degree in Physics at Orsay University (Paris) in 2001. After being with Rome-3 University from 1992 to 2004. He has been a full professor in Physics at Paris Diderot University since 2004, and in charge of the Nonlinear Devices group of MPQ Laboratory since 2006. His research areas include nonlinear optics, micro- and nano-photonics and optoelectronics, with a focus on AlGaAs platform. He has coordinated several research programs and co-authored 100 peer-reviewed journal articles, 200 conference papers, 10 book chapters and also has 4 patents.

Dragomir N. Neshev is a Professor in physics and the leader of the Experimental Photonics Group at the Nonlinear Physics Centre, at Australian National University (ANU). He received his Ph.D. degree from Sofia University, Bulgaria in 1999. Since then he has worked in the field of nonlinear optics at several research centres around the world and joined ANU in 2002. He is the recipient of several awards, including a Queen Elizabeth II Fellowship; an Australian Research Fellowship; a Marie-Curie Individual Fellowship; and the Academic award for best young scientist of Sofia University. His activities span over several branches of optics, including nonlinear periodic structures, singular optics, plasmonics, and photonic metamaterials. He has co-authored 200 publications in international peer-reviewed scientific journals.

1. Metasurfaces, then and now. 2. Semiconductor-Loaded Nonlinear Metasurfaces. 3. Technological challenges and material platforms. 4. Nonlinear Plasmonic Metasurfaces. 5. Quantum nonlinear metasurfaces. 6. Ultrafast responses of Mie-resonant semiconductor nanostructures. 7. Nonlinear Photonic Crystals. 8. Nonlinear and quantum effects in integrated microcavities. 9. Harmonic generation with Mie resonant nanostructures. 10. Future Perspectives