Lattice modes mediate radiative coupling in metamaterial arrays.
We show that a resonant response with very high quality factors can be achieved in periodic metamaterials by radiatively coupling their structural elements. The coupling is mediated by lattice modes and can be efficiently controlled by tuning the lattice periodicity. Using a recently developed terahertz (THz) near-field imaging technique and conventional far-field spectroscopy together with numerical simulations we pinpoint the underlying mechanisms. In the strong coupling regimes we identify avoided crossings between the plasmonic eigenmodes and the diffractive lattice modes.
Bitzer
Andreas
A
Freiburg Materials Research Center, University of Freiburg, Freiburg, Germany. andreas.bitzer@gmail.com
Wallauer
Jan
J
Helm
Hanspeter
H
Merbold
Hannes
H
Feurer
Thomas
T
Walther
Markus
M
D003198:Computer Simulation; D004867:Equipment Design; D008422:Materials Testing; D008962:Models, Theoretical; D055095:Optics and Photonics; D020349:Surface Plasmon Resonance; D055053:Terahertz Radiation; D055068:Terahertz Spectroscopy / Q000295:instrumentation / Q000379:methods*