Wedge Waveguides and Resonators for Quantum Plasmonics.
Plasmonic structures can provide deep-subwavelength electromagnetic fields that are useful for enhancing light-matter interactions. However, because these localized modes are also dissipative, structures that offer the best compromise between field confinement and loss have been sought. Metallic wedge waveguides were initially identified as an ideal candidate but have been largely abandoned because to date their experimental performance has been limited. We combine state-of-the-art metallic wedges with integrated reflectors and precisely placed colloidal quantum dots (down to the single-emitter level) and demonstrate quantum-plasmonic waveguides and resonators with performance approaching theoretical limits. By exploiting a nearly 10-fold improvement in wedge-plasmon propagation (19 μm at a vacuum wavelength, λvac, of 630 nm), efficient reflectors (93%), and effective coupling (estimated to be >70%) to highly emissive (~90%) quantum dots, we obtain Ag plasmonic resonators at visible wavelengths with quality factors approaching 200 (3.3 nm line widths). As our structures offer modal volumes down to ~0.004λvac(3) in an exposed single-mode waveguide-resonator geometry, they provide advantages over both traditional photonic microcavities and localized-plasmonic resonators for enhancing light-matter interactions. Our results confirm the promise of wedges for creating plasmonic devices and for studying coherent quantum-plasmonic effects such as long-distance plasmon-mediated entanglement and strong plasmon-matter coupling.
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Stephan J P
SJ
Kress
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Felipe V
FV
Antolinez
Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich , 8092 Zurich, Switzerland.
Patrizia
P
Richner
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.|Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Sriharsha V
SV
Jayanti
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
David K
DK
Kim
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Ferry
F
Prins
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Andreas
A
Riedinger
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Maximilian P C
MP
Fischer
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Stefan
S
Meyer
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
Kevin M
KM
McPeak
Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich , 8092 Zurich, Switzerland.
Dimos
D
Poulikakos
Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
David J
DJ
Norris
Plasmonic waveguides; colloidal quantum dots; nanophotonics; plasmonic resonators; quantum plasmonics; semiconductor nanocrystals