title: Tunable silicon photonics directional coupler driven by a transverse temperature gradient.
abstract: A compact directional coupler fabricated on a silicon photonic platform is presented, with a power-splitting ratio that can be tuned through a transverse temperature gradient induced by a laterally shifted integrated heater. The tuning mechanism exploits the thermally induced phase velocity mismatch between the coupled modes of the silicon waveguides. The positions of the integrated heater and the waveguide design are optimized to maximize the tuning range and to reduce electric power consumption. Asynchronous devices with an intrinsic phase mismatch are demonstrated to be more efficient, providing a tunable coupled power from 0.7 to 0.01 with 36 mW maximum power dissipation.
authors.affiliation: Dipartimento di Ingegneria dell'Energia Elettrica e dell'Informazione, Università di Bologna, Bologna, Italy. piero.orlandi@unibo.it
authors.forename: Piero
authors.initials: P
authors.lastname: Orlandi
authors.forename: Francesco
authors.initials: F
authors.lastname: Morichetti
authors.forename: Michael John
authors.initials: MJ
authors.lastname: Strain
authors.forename: Marc
authors.initials: M
authors.lastname: Sorel
authors.forename: Andrea
authors.initials: A
authors.lastname: Melloni
authors.forename: Paolo
authors.initials: P
authors.lastname: Bassi