title: Individual nanoantennas loaded with three-dimensional optical nanocircuits.
abstract: Nanoantennas are key optical components that bridge nanometer-scale optical signals to far-field, free-space radiation. In analogy to radio frequency antennas where tuning and impedance-matching are accomplished with lumped circuit elements, one could envision nanoantenna properties controlled by nanoscale, optical frequency circuit elements in which circuit operations are based on photons rather than electrons. A recent investigation of the infrared nanocircuits has demonstrated the filtering functionality using dielectric gratings. However, these two-dimensional prototypes have limited applicability in real-life devices. Here we experimentally demonstrate the first optical nanoscale circuits with fully three-dimensional lumped elements, which we use to tune and impedance-match a single optical dimer nanoantenna. We control the antenna resonance and impedance bandwidth using suitably designed loads with combinations of basic circuit elements: nanoscale capacitors, inductors, and resistors. Our results pave the way toward extending conventional circuit concepts into the visible domain for applications in data storage, wireless optical links, and related venues.
authors.affiliation: Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Fangfang
authors.initials: F
authors.lastname: Wen
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yumin
authors.initials: Y
authors.lastname: Wang
authors.forename: Peter
authors.initials: P
authors.lastname: Nordlander
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas
authors.forename: Andrea
authors.initials: A
authors.lastname: Alù