title: Graphene-assisted control of coupling between optical waveguides.
abstract: The unique properties of optical waveguides electrically controlled by means of graphene layers are investigated. We demonstrate that, thanks to tunable losses induced by graphene layers, a careful design of silicon on silica ridge waveguides can be used to explore passive PT-symmetry breaking in directional couplers. We prove that the exceptional point of the system can be probed by varying the applied voltage and we thus propose very compact photonic structures which can be exploited to control coupling between waveguides and to tailor discrete diffraction in arrays.
authors.affiliation: Dipartimento di Ingegneria dell’Informazione, Universit`a degli Studi di Brescia, Brescia 25123, Italy. andrea.locatelli@ing.unibs.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Locatelli
authors.forename: Antonio-Daniele
authors.initials: AD
authors.lastname: Capobianco
authors.forename: Michele
authors.initials: M
authors.lastname: Midrio
authors.forename: Stefano
authors.initials: S
authors.lastname: Boscolo
authors.forename: Costantino
authors.initials: C
authors.lastname: De Angelis
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry* / Q000528:radiation effects*; D012031:Refractometry / Q000295:instrumentation*; D014159:Transducers
chemical_list: D006108:Graphite