We investigate the tuning of the coupling of surface plasmon polaritons between two spatially separated graphene layers. We demonstrate that by slightly changing the chemical potential, a graphene coupler can switch from the bar to the cross state; as a consequence, the coupling coefficient in such structures can be easily controlled by means of an applied electrical signal.
© 2013 Optical Society of America
Original Manuscript: July 22, 2013
Revised Manuscript: September 6, 2013
Manuscript Accepted: September 6, 2013
Published: October 14, 2013
Aldo Auditore, Costantino de Angelis, Andrea Locatelli, and Alejandro B. Aceves, "Tuning of surface plasmon polaritons beat length in graphene directional couplers," Opt. Lett. 38, 4228-4231 (2013)