Graphene, a single-layer of carbon atoms arranged in a two-dimensional honeycomb lattice is nowadays attracting considerable attention for a variety of photonic applications, including fast photodetectors, transparent electrodes in displays and photovoltaic modules, and saturable absorbers. Owing to its high carrier mobility, gapless spectrum, and frequency-independent absorption coefficient, it has been precognized as a very promising element for the development of detectors and modulators operating in the Terahertz (THz) region of the electromagnetic spectrum, which is still severely lacking in terms of solid-state devices. I will illustrate the realization of THz detectors based on antenna-coupled graphene field-effect transistors (FETs), and discuss the development and applications of electrically switchable metamaterial devices. Prospects for the use of graphene in a new generation of THz sources, both directly and as saturable absorber for laser mode-locking, will be analyzed. Finally, coherent perfect absorption processes and possible applications will be presented.
Alessandro Tredicucci was born in Chiavari, Italy, in 1968. He received the Ph.D. degree in physics from the Scuola Normale Superiore of Pisa in 1997, focusing on exciton-polariton propagation in confined systems and modifications of light-matter interaction in microcavities. From 1997 to 2000, he was at Bell Laboratories, Lucent Technologies, Murray Hill, NJ, where he worked on the development of novel quantum cascade lasers with superlattice active regions. He moved then back to Pisa, first at the NEST center of Istituto Nanoscienze - CNR and Scuola Normale Superiore till 2014, and now, as Full Professor of Condensed Matter Physics, at the University of Pisa. His activity is mainly concerned with devices for the generation and detection of THz radiation and with the investigation of new regimes of light-matter interaction. The first demonstration of a THz quantum cascade laser, the first observation of intersubband polaritons, and the implementation of the first THz detector in graphene are among his best-known achievements. Dr. Tredicucci was the recipient of several awards, among which the 2003 S. Panizza award for opto-electronics of the Italian Physical Society, the 2005 S. Campisano prize for condensed matter physics of the CNR, the 2013 Nick Holonyak Jr. award for semiconductor optics of the Optical Society of America, and the 2014 Occhialini prize of the Institute of Physics. He is a Fellow of the Optical Society of America since 2014.