| Autor: |
Kress SJP; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Cui J; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Rohner P; Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland., Kim DK; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Antolinez FV; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Zaininger KA; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Jayanti SV; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Richner P; Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland., McPeak KM; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland., Poulikakos D; Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland., Norris DJ; Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland. |
| Abstrakt: |
Colloidal quantum dots are robust, efficient, and tunable emitters now used in lighting, displays, and lasers. Consequently, when the spaser-a laser-like source of high-intensity, narrow-band surface plasmons-was first proposed, quantum dots were specified as the ideal plasmonic gain medium for overcoming the significant intrinsic losses of plasmons. Many subsequent spasers, however, have required a single material to simultaneously provide gain and define the plasmonic cavity, a design unable to accommodate quantum dots and other colloidal nanomaterials. In addition, these and other designs have been ill suited for integration with other elements in a larger plasmonic circuit, limiting their use. We develop a more open architecture that decouples the gain medium from the cavity, leading to a versatile class of quantum dot-based spasers that allow controlled generation, extraction, and manipulation of plasmons. We first create aberration-corrected plasmonic cavities with high quality factors at desired locations on an ultrasmooth silver substrate. We then incorporate quantum dots into these cavities via electrohydrodynamic printing or drop-casting. Photoexcitation under ambient conditions generates monochromatic plasmons (0.65-nm linewidth at 630 nm, Q ~ 1000) above threshold. This signal is extracted, directed through an integrated amplifier, and focused at a nearby nanoscale tip, generating intense electromagnetic fields. More generally, our device platform can be straightforwardly deployed at different wavelengths, size scales, and geometries on large-area plasmonic chips for fundamental studies and applications. |
