title: Critical coupling in plasmonic resonator arrays.
abstract: We report critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moiré surfaces. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. The critical coupling conditions depend on the superperiod of the Moiré surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have a relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Analytical and finite difference time domain calculations support the experimental observations.
authors.affiliation: Department of Physics, Advanced Research Laboratories and Turk Telekom Laboratory, Bilkent University, 06800 Ankara, Turkey. balci@fen.bilkent.edu.tr
authors.forename: Sinan
authors.initials: S
authors.lastname: Balci
authors.forename: Coskun
authors.initials: C
authors.lastname: Kocabas
authors.forename: Atilla
authors.initials: A
authors.lastname: Aydinli