1
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Komatsu K, Pápa Z, Jauk T, Bernecker F, Tóth L, Lackner F, Ernst WE, Ditlbacher H, Krenn JR, Ossiander M, Dombi P, Schultze M. Few-Cycle Surface Plasmon Polaritons. Nano Lett 2024; 24:2637-2642. [PMID: 38345784 PMCID: PMC10906073 DOI: 10.1021/acs.nanolett.3c04991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 02/29/2024]
Abstract
Surface plasmon polaritons (SPPs) can confine and guide light in nanometer volumes and are ideal tools for achieving electric field enhancement and the construction of nanophotonic circuitry. The realization of the highest field strengths and fastest switching requires confinement also in the temporal domain. Here, we demonstrate a tapered plasmonic waveguide with an optimized grating structure that supports few-cycle surface plasmon polaritons with >70 THz bandwidth while achieving >50% light-field-to-plasmon coupling efficiency. This enables us to observe the─to our knowledge─shortest reported SPP wavepackets. Using time-resolved photoelectron microscopy with suboptical-wavelength spatial and sub-10 fs temporal resolution, we provide full spatiotemporal imaging of co- and counter-propagating few-cycle SPP wavepackets along tapered plasmonic waveguides. By comparing their propagation, we track the evolution of the laser-plasmon phase, which can be controlled via the coupling conditions.
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Affiliation(s)
- Kazma Komatsu
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
| | - Zsuzsanna Pápa
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
| | - Thomas Jauk
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
| | - Felix Bernecker
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
| | - Lázár Tóth
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
| | - Florian Lackner
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
| | - Wolfgang E. Ernst
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
| | | | | | - Marcus Ossiander
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
- Harvard
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Péter Dombi
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
| | - Martin Schultze
- Institute
of Experimental Physics, Graz University
of Technology, 8010 Graz, Austria
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2
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Belitsch M, Dirin DN, Kovalenko MV, Pichler K, Rotter S, Ghalgaoui A, Ditlbacher H, Hohenau A, Krenn JR. Gain and lasing from CdSe/CdS nanoplatelet stripe waveguides. Micro and Nano Engineering 2022. [DOI: 10.1016/j.mne.2022.100167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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Schwarzl R, Heim P, Schiek M, Grimaldi D, Hohenau A, Krenn JR, Koch M. Transient absorption microscopy setup with multi-ten-kilohertz shot-to-shot subtraction and discrete Fourier analysis. Opt Express 2022; 30:34385-34395. [PMID: 36242451 DOI: 10.1364/oe.466272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/18/2022] [Indexed: 06/16/2023]
Abstract
Recording of transient absorption microscopy images requires fast detection of minute optical density changes, which is typically achieved with high-repetition-rate laser sources and lock-in detection. Here, we present a highly flexible and cost-efficient detection scheme based on a conventional photodiode and an USB oscilloscope with MHz bandwidth, that deviates from the commonly used lock-in setup and achieves benchmark sensitivity. Our scheme combines shot-to-shot evaluation of pump-probe and probe-only measurements, a home-built photodetector circuit optimized for low pulse energies applying low-pass amplification, and a custom evaluation algorithm based on Fourier transformation. Advantages of this approach include abilities to simultaneously monitor multiple pulse modulation frequencies, implement the detection of additional pulse sequences (e.g., pump-only), and expand to multiple parallel detection channels for wavelength-dispersive probing. With a 40 kHz repetition-rate laser system powering two non-collinear optical parametric amplifiers for wide tuneability, we find that laser pulse fluctuations limit the sensitivity of the setup, while the detection scheme has negligible contribution. We demonstrate the 2-D imaging performance of our transient absorption microscope with studies on micro-crystalline molecular thin films.
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4
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Grimaldi D, Kelderer E, Dirin DN, Kovalenko MV, Hohenau A, Ditlbacher H, Krenn JR. Photoconductivity of PbS/perovskite quantum dots in gold nanogaps. Nanoscale Adv 2022; 4:3566-3572. [PMID: 36134347 PMCID: PMC9400517 DOI: 10.1039/d2na00284a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Abstract
We demonstrate that the photoconductance of colloidal PbS/MAPbI3 quantum dots in nanoscale gold electrode gaps shows a consistent power law dependence of the photocurrent on the light intensity with an exponent slightly below 0.7. The gap sizes are between 25 and 800 nm and by scanning photocurrent microscopy we evidence the strong localization and high reproducibility of photocurrent generation. We probe different flat-faced and pointed electrodes for excitation light in the red and near infrared spectral range and laser irradiances from 10-2 to 102 W cm-2. Our material combination provides practically identical photocurrent response for a wide range of gap sizes and geometries, highlighting its generic potential for nanoscale light coupling and detection.
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Affiliation(s)
- Dario Grimaldi
- Institute of Physics, University of Graz 8010 Graz Austria
| | - Emil Kelderer
- Institute of Physics, University of Graz 8010 Graz Austria
| | - Dmitry N Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich 8093 Zürich Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics 8600 Dübendorf Switzerland
| | - Maksym V Kovalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich 8093 Zürich Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics 8600 Dübendorf Switzerland
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5
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Lovász B, Sándor P, Kiss GZ, Bánhegyi B, Rácz P, Pápa Z, Budai J, Prietl C, Krenn JR, Dombi P. Nonadiabatic Nano-optical Tunneling of Photoelectrons in Plasmonic Near-Fields. Nano Lett 2022; 22:2303-2308. [PMID: 35240778 PMCID: PMC8949759 DOI: 10.1021/acs.nanolett.1c04651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Nonadiabatic nano-optical electron tunneling in the transition region between multiphoton-induced emission and adiabatic tunnel emission is explored in the near-field of plasmonic nanostructures. For Keldysh γ values between ∼1.3 and ∼2.2, measured photoemission spectra show strong-field recollision driven by the nanoscale near-field. At the same time, the photoemission yield shows an intensity scaling with a constant nonlinearity, which is characteristic for multiphoton-induced emission. Our observations in this transition region were well reproduced with the numerical solution of Schrödinger's equation, mimicking the nanoscale geometry of the field. This way, we determined the boundaries and nature of nonadiabatic tunneling photoemission, building on a key advantage of a nanoplasmonic system, namely, that high-field-driven recollision events and their signature in the photoemission spectrum can be observed more efficiently due to significant nanoplasmonic field enhancement factors.
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Affiliation(s)
- Béla Lovász
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
| | - Péter Sándor
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
| | | | | | - Péter Rácz
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
| | - Zsuzsanna Pápa
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
| | - Judit Budai
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
| | | | | | - Péter Dombi
- Wigner
Research Centre for Physics, 1121 Budapest, Hungary
- ELI-ALPS
Research Institute, 6728 Szeged, Hungary
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6
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Schmidt FP, Losquin A, Horák M, Hohenester U, Stöger-Pollach M, Krenn JR. Fundamental Limit of Plasmonic Cathodoluminescence. Nano Lett 2021; 21:590-596. [PMID: 33336569 PMCID: PMC7809694 DOI: 10.1021/acs.nanolett.0c04084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/27/2020] [Indexed: 06/12/2023]
Abstract
We use cathodoluminescence (CL) spectroscopy in a transmission electron microscope to probe the radial breathing mode of plasmonic silver nanodisks. A two-mirror detection system sandwiching the sample collects the CL emission in both directions, that is, backward and forward with respect to the electron beam trajectory. We unambiguously identify a spectral shift of about 8 nm in the CL spectra acquired from both sides and show that this asymmetry is induced by the electron beam itself. By numerical simulations, we confirm the observations and identify the underlying physical effect due to the interference of the CL emission patterns of an electron-beam-induced dipole and the breathing mode. This effect can ultimately limit the achievable fidelity in CL measurements on any system involving multiple excitations and should therefore be considered with care in high-precision experiments.
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Affiliation(s)
| | - Arthur Losquin
- Thales
Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767, France
| | - Michal Horák
- Central
European Institute of Technology, Brno University
of Technology, Brno Purkynǒva 123, 612 00, Czech Republic
| | - Ulrich Hohenester
- Institute
of Physics, University of Graz, Universitätsplatz 5, Graz 8010, Austria
| | - Michael Stöger-Pollach
- University
Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, Wien 1040, Austria
| | - Joachim R. Krenn
- Institute
of Physics, University of Graz, Universitätsplatz 5, Graz 8010, Austria
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7
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Schaffernak G, Krug MK, Belitsch M, Gašparić M, Ditlbacher H, Hohenester U, Krenn JR, Hohenau A. Plasmonic Dispersion Relations and Intensity Enhancement of Metal-Insulator-Metal Nanodisks. ACS Photonics 2018; 5:4823-4827. [PMID: 30591924 PMCID: PMC6302311 DOI: 10.1021/acsphotonics.8b00938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Indexed: 05/15/2023]
Abstract
We show that the plasmon modes of vertically stacked Ag-SiO2-Ag nanodisks can be understood and classified as hybridized surface and edge modes. We describe their universal dispersion relations and demonstrate that coupling-induced spectral shifts are significantly stronger for surface modes than for edge modes. The experimental data correspond well to numerical simulations. In addition, we estimate optical intensity enhancements of the stacked nanodisks in the range of 1000.
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8
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Schmidt FP, Losquin A, Hofer F, Hohenau A, Krenn JR, Kociak M. How Dark Are Radial Breathing Modes in Plasmonic Nanodisks? ACS Photonics 2018; 5:861-866. [PMID: 29607350 PMCID: PMC5871341 DOI: 10.1021/acsphotonics.7b01060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Indexed: 05/06/2023]
Abstract
Due to a vanishing dipole moment, radial breathing modes in small flat plasmonic nanoparticles do not couple to light and have to be probed with a near-field source, as in electron energy loss spectroscopy (EELS). With increasing particle size, retardation gives rise to light coupling, enabling probing breathing modes optically or by cathodoluminescence (CL). Here, we investigate single silver nanodisks with diameters of 150-500 nm by EELS and CL in an electron microscope and quantify the EELS/CL ratio, which corresponds to the ratio of full to radiative damping of the breathing mode. For the investigated diameter range, we find the CL signal to increase by about 1 order of magnitude, in agreement with numerical simulations. Due to reciprocity, our findings corroborate former optical experiments and enable a quantitative understanding of the light coupling of dark plasmonic modes.
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Affiliation(s)
- Franz-Philipp Schmidt
- Institute
of Physics, University of Graz, Graz 8010, Austria
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Graz 8010, Austria
- E-mail:
| | - Arthur Losquin
- Department
of Physics, Lund University, Lund 221 00, Sweden
- Laboratoire
Ondes et Matière d’Aquitaine, UMR 5798, CNRS-University of Bordeaux, F-33405 Talence Cedex, France
| | - Ferdinand Hofer
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Graz 8010, Austria
| | - Andreas Hohenau
- Institute
of Physics, University of Graz, Graz 8010, Austria
| | | | - Mathieu Kociak
- Laboratoire
de Physique des Solides, CNRS UMR 8502,
Université Paris-Sud, 91405 Orsay, France
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9
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Haberfehlner G, Schmidt FP, Schaffernak G, Hörl A, Trügler A, Hohenau A, Hofer F, Krenn JR, Hohenester U, Kothleitner G. 3D Imaging of Gap Plasmons in Vertically Coupled Nanoparticles by EELS Tomography. Nano Lett 2017; 17:6773-6777. [PMID: 28981295 PMCID: PMC5683695 DOI: 10.1021/acs.nanolett.7b02979] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Plasmonic gap modes provide the ultimate confinement of optical fields. Demanding high spatial resolution, the direct imaging of these modes was only recently achieved by electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). However, conventional 2D STEM-EELS is only sensitive to components of the photonic local density of states (LDOS) parallel to the electron trajectory. It is thus insensitive to specific gap modes, a restriction that was lifted with the introduction of tomographic 3D EELS imaging. Here, we show that by 3D EELS tomography the gap mode LDOS of a vertically stacked nanotriangle dimer can be fully imaged. Besides probing the complete mode spectrum, we demonstrate that the tomographic approach allows disentangling the signal contributions from the two nanotriangles that superimpose in a single measurement with a fixed electron trajectory. Generally, vertically coupled nanoparticles enable the tailoring of 3D plasmonic fields, and their full characterization will thus aid the development of complex nanophotonic devices.
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Affiliation(s)
- Georg Haberfehlner
- Graz
Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz, Austria
- Institute
of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
- E-mail:
| | - Franz-Philipp Schmidt
- Institute
of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Gernot Schaffernak
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Anton Hörl
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Andreas Trügler
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Andreas Hohenau
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Ferdinand Hofer
- Graz
Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz, Austria
- Institute
of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Joachim R. Krenn
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Ulrich Hohenester
- Institute
of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Gerald Kothleitner
- Graz
Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz, Austria
- Institute
of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
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10
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Rácz P, Pápa Z, Márton I, Budai J, Wróbel P, Stefaniuk T, Prietl C, Krenn JR, Dombi P. Measurement of Nanoplasmonic Field Enhancement with Ultrafast Photoemission. Nano Lett 2017; 17:1181-1186. [PMID: 28094992 DOI: 10.1021/acs.nanolett.6b04893] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Probing nanooptical near-fields is a major challenge in plasmonics. Here, we demonstrate an experimental method utilizing ultrafast photoemission from plasmonic nanostructures that is capable of probing the maximum nanoplasmonic field enhancement in any metallic surface environment. Directly measured field enhancement values for various samples are in good agreement with detailed finite-difference time-domain simulations. These results establish ultrafast plasmonic photoelectrons as versatile probes for nanoplasmonic near-fields.
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Affiliation(s)
- Péter Rácz
- MTA "Lendület" Ultrafast Nanooptics Group, Wigner Research Centre for Physics , 1121 Budapest, Hungary
| | - Zsuzsanna Pápa
- ELI-ALPS Research Institute , ELI-HU Nonprofit Kft., 6720 Szeged, Hungary
- Department of Optics and Quantum Electronics, University of Szeged , 6720 Szeged, Hungary
| | - István Márton
- MTA "Lendület" Ultrafast Nanooptics Group, Wigner Research Centre for Physics , 1121 Budapest, Hungary
| | - Judit Budai
- ELI-ALPS Research Institute , ELI-HU Nonprofit Kft., 6720 Szeged, Hungary
- Department of Optics and Quantum Electronics, University of Szeged , 6720 Szeged, Hungary
| | - Piotr Wróbel
- Faculty of Physics, University of Warsaw , 02-093 Warsaw, Poland
| | - Tomasz Stefaniuk
- Faculty of Physics, University of Warsaw , 02-093 Warsaw, Poland
| | - Christine Prietl
- Institut für Physik, Karl-Franzens Universität Graz , 8010 Graz, Austria
| | - Joachim R Krenn
- Institut für Physik, Karl-Franzens Universität Graz , 8010 Graz, Austria
| | - Péter Dombi
- MTA "Lendület" Ultrafast Nanooptics Group, Wigner Research Centre for Physics , 1121 Budapest, Hungary
- ELI-ALPS Research Institute , ELI-HU Nonprofit Kft., 6720 Szeged, Hungary
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11
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Schmidt FP, Hofer F, Krenn JR. Spectrum image analysis tool – A flexible MATLAB solution to analyze EEL and CL spectrum images. Micron 2017; 93:43-51. [DOI: 10.1016/j.micron.2016.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 11/25/2022]
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12
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Krug MK, Schaffernak G, Belitsch M, Gašparić M, Leitgeb V, Trügler A, Hohenester U, Krenn JR, Hohenau A. Mapping the local particle plasmon sensitivity with a scanning probe. Nanoscale 2016; 8:16449-16454. [PMID: 27603414 PMCID: PMC5048393 DOI: 10.1039/c6nr05800k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 08/29/2016] [Indexed: 05/31/2023]
Abstract
We probe the local sensitivity of an optically excited plasmonic nanoparticle by changing the local dielectric environment through a scanning glass fiber tip. Recording the particle plasmon scattering spectrum for each tip position allows us to observe spectral resonance shifts concurrent with changes in scattering intensity and plasmon damping. For the tip-induced spectral shifts we find the strongest sensitivity at the particle edges, in accordance with the spatial plasmonic field profile. In contrast, the strongest sensitivity occurs at the center of the particle if the scattering intensity is probed at the short wavelength slope of the plasmon resonance instead of the resonance position. This bears important implications for plasmonic sensing, in particular when done at a single light wavelength.
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Affiliation(s)
- Markus K. Krug
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | | | - Martin Belitsch
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | - Marija Gašparić
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | - Verena Leitgeb
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | - Andreas Trügler
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | | | - Joachim R. Krenn
- Institute of Physics , University of Graz , 8010 Graz , Austria .
| | - Andreas Hohenau
- Institute of Physics , University of Graz , 8010 Graz , Austria .
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13
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Schmidt FP, Ditlbacher H, Hohenau A, Hohenester U, Hofer F, Krenn JR. Edge Mode Coupling within a Plasmonic Nanoparticle. Nano Lett 2016; 16:5152-5. [PMID: 27427962 PMCID: PMC5058635 DOI: 10.1021/acs.nanolett.6b02097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/15/2016] [Indexed: 05/07/2023]
Abstract
The coupling of plasmonic nanoparticles can strongly modify their optical properties. Here, we show that the coupling of the edges within a single rectangular particle leads to mode splitting and the formation of bonding and antibonding edge modes. We are able to unambiguously designate the modes due to the high spatial resolution of electron microscopy-based electron energy loss spectroscopy and the comparison with numerical simulations. Our results provide simple guidelines for the interpretation and the design of plasmonic mode spectra.
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Affiliation(s)
- Franz-Philipp Schmidt
- Institute of Physics, University of Graz, 8010 Graz, Austria
- Institute for Electron
Microscopy and Nanoanalysis, Graz University
of Technology, 8010 Graz, Austria
| | | | - Andreas Hohenau
- Institute of Physics, University of Graz, 8010 Graz, Austria
| | | | - Ferdinand Hofer
- Institute for Electron
Microscopy and Nanoanalysis, Graz University
of Technology, 8010 Graz, Austria
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14
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Leitgeb V, Trügler A, Köstler S, Krug MK, Hohenester U, Hohenau A, Leitner A, Krenn JR. Three dimensional sensitivity characterization of plasmonic nanorods for refractometric biosensors. Nanoscale 2016; 8:2974-2981. [PMID: 26781940 DOI: 10.1039/c5nr06401e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An experimental three dimensional characterization of the local refractive index sensitivity of plasmonic gold nanorods is performed by controlled apposition of lithographic nanostructures. We show up to seven times higher sensitivity values to local changes in the refractive index at the particle tip than center. In addition, successive deposition of defined nm-thin dielectric layers on nanorods covered with stripe masks allows us to study the sensitivity decrease normal to the particle surface separately for different particle sites. Clear trends to a stronger sensitivity decay at sites of higher local sensitivity are demonstrated experimentally and theoretically. Our sensitivity characterization provides an important tool to find the most suitable particle type and particle site for specific bio-sensing applications.
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Affiliation(s)
- V Leitgeb
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - A Trügler
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - S Köstler
- JOANNEUM RESEARCH Forschungsgesellschaft mbH, MATERIALS-Institut für Oberflächentechnologien und Photonik, Leonhardstraße 59, 8010 Graz, Austria
| | - M K Krug
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - U Hohenester
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - A Hohenau
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - A Leitner
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
| | - J R Krenn
- Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.
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15
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Schmidt FP, Ditlbacher H, Trügler A, Hohenester U, Hohenau A, Hofer F, Krenn JR. Plasmon modes of a silver thin film taper probed with STEM-EELS. Opt Lett 2015; 40:5670-5673. [PMID: 26625078 DOI: 10.1364/ol.40.005670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
By focusing propagating surface plasmons, electromagnetic energy can be delivered to nanoscale volumes. In this context, we employ electron energy loss spectroscopy in a scanning transmission electron microscope to characterize the full plasmonic mode spectrum of a silver thin film tapered to a sharp tip. We show that the plasmon modes can be ordered in film and edge modes and corroborate our assignment through supplementary numerical simulations. In particular, we find that the focused plasmon field at the taper tip is fueled by edge modes.
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16
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Häfele V, Trügler A, Hohenester U, Hohenau A, Leitner A, Krenn JR. Local refractive index sensitivity of gold nanodisks. Opt Express 2015; 23:10293-10300. [PMID: 25969071 DOI: 10.1364/oe.23.010293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We experimentally investigate the local refractive index sensitivity of plasmonic gold nanodisks by applying small polymer dots to selected disk sites by means of two-step lithography. Measured sensitivity profiles obtained from tracking the polymer-induced spectral shift of the plasmon modes are in excellent agreement with numerical simulation of both spectral sensitivity and the electric near field of the nanodisks. Based on the nanodisk sensitivity profile we tailor a sensitive and spatially uniform plasmonic sensor by capping the disk with a dielectric layer, thus restricting analyte access to the disk rim.
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17
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Schmidt F, Ditlbacher H, Hofer F, Krenn JR, Hohenester U. Morphing a plasmonic nanodisk into a nanotriangle. Nano Lett 2014; 14:4810-5. [PMID: 25000389 PMCID: PMC4133183 DOI: 10.1021/nl502027r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 06/30/2014] [Indexed: 05/23/2023]
Abstract
We morph a silver nanodisk into a nanotriangle by producing a series of nanoparticles with electron beam lithography. Using electron energy loss spectroscopy (EELS), we map out the plasmonic eigenmodes and trace the evolution of edge and film modes during morphing. Our results suggest that disk modes, characterized by angular order, can serve as a suitable basis for other nanoparticle geometries and are subject to resonance energy shifts and splittings, as well as to hybridization upon morphing. Similar to the linear combination of atomic orbitals (LCAO) in quantum chemistry, we introduce a linear combination of plasmonic eigenmodes to describe plasmon modes in different geometries, hereby extending the successful hybridization model of plasmonics.
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Affiliation(s)
- Franz
P. Schmidt
- Institut
für Physik, Karl−Franzens−Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
- Institute
for Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, 8010 Graz, Austria
| | - Harald Ditlbacher
- Institut
für Physik, Karl−Franzens−Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Ferdinand Hofer
- Institute
for Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, 8010 Graz, Austria
| | - Joachim R. Krenn
- Institut
für Physik, Karl−Franzens−Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Ulrich Hohenester
- Institut
für Physik, Karl−Franzens−Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
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18
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Petritz A, Wolfberger A, Fian A, Krenn JR, Griesser T, Stadlober B. High performance p-type organic thin film transistors with an intrinsically photopatternable, ultrathin polymer dielectric layer. Org Electron 2013; 14:3070-3082. [PMID: 24748853 PMCID: PMC3990428 DOI: 10.1016/j.orgel.2013.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 07/08/2013] [Accepted: 07/12/2013] [Indexed: 05/29/2023]
Abstract
A high-performing bottom-gate top-contact pentacene-based oTFT technology with an ultrathin (25-48 nm) and electrically dense photopatternable polymeric gate dielectric layer is reported. The photosensitive polymer poly((±)endo,exo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, diphenylester) (PNDPE) is patterned directly by UV-exposure (λ = 254 nm) at a dose typical for conventionally used negative photoresists without the need for any additional photoinitiator. The polymer itself undergoes a photo-Fries rearrangement reaction under UV illumination, which is accompanied by a selective cross-linking of the macromolecules, leading to a change in solubility in organic solvents. This crosslinking reaction and the negative photoresist behavior are investigated by means of sol-gel analysis. The resulting transistors show a field-effect mobility up to 0.8 cm2 V-1 s-1 at an operation voltage as low as -4.5 V. The ultra-low subthreshold swing in the order of 0.1 V dec-1 as well as the completely hysteresis-free transistor characteristics are indicating a very low interface trap density. It can be shown that the device performance is completely stable upon UV-irradiation and development according to a very robust chemical rearrangement. The excellent interface properties, the high stability and the small thickness make the PNDPE gate dielectric a promising candidate for fast organic electronic circuits.
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Affiliation(s)
- Andreas Petritz
- Materials-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, Weiz A-8160, Austria
| | - Archim Wolfberger
- Chemistry of Polymeric Materials, University of Leoben, Otto Glöckel-Straße 2, Leoben A-8700, Austria
| | - Alexander Fian
- Materials-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, Weiz A-8160, Austria
| | | | - Thomas Griesser
- Chemistry of Polymeric Materials, University of Leoben, Otto Glöckel-Straße 2, Leoben A-8700, Austria
| | - Barbara Stadlober
- Materials-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, Weiz A-8160, Austria
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19
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Gruber C, Trügler A, Hohenau A, Hohenester U, Krenn JR. Spectral modifications and polarization dependent coupling in tailored assemblies of quantum dots and plasmonic nanowires. Nano Lett 2013; 13:4257-62. [PMID: 23968490 PMCID: PMC3772860 DOI: 10.1021/nl4019947] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 08/05/2013] [Indexed: 05/23/2023]
Abstract
The coupling of optical emitters with a nanostructured environment is at the heart of nano- and quantum optics. We control this coupling by the lithographic positioning of a few (1-3) quantum dots (QDs) along plasmonic silver nanowires with nanoscale resolution. The fluorescence emission from the QD-nanowire systems is probed spectroscopically, by microscopic imaging and decay time measurements. We find that the plasmonic modes can strongly modulate the fluorescence emission. For a given QD position, the local plasmon field dictates the coupling efficiency, and thus the relative weight of free space radiation and emission into plasmon modes. Simulations performed with a generic few-level model give very good agreement with experiment. Our data imply that the 2D degenerate emission dipole orientation of the QD can be forced to predominantly emit to one polarization component dictated by the nanowire modes.
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Affiliation(s)
- Christian Gruber
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria
| | - Andreas Trügler
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria
| | - Andreas Hohenau
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria
| | - Ulrich Hohenester
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria
| | - Joachim R. Krenn
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria
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20
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Zhang Y, Boer-Duchemin E, Wang T, Rogez B, Comtet G, Le Moal E, Dujardin G, Hohenau A, Gruber C, Krenn JR. Edge scattering of surface plasmons excited by scanning tunneling microscopy. Opt Express 2013; 21:13938-13948. [PMID: 23787583 DOI: 10.1364/oe.21.013938] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The scattering of electrically excited surface plasmon polaritons (SPPs) into photons at the edges of gold metal stripes is investigated. The SPPs are locally generated by the inelastic tunneling current of a scanning tunneling microscope (STM). The majority of the collected light arising from the scattering of SPPs at the stripe edges is emitted in the forward direction and is collected at large angle (close to the air-glass critical angle, θ(c)). A much weaker isotropic component of the scattered light gives rise to an interference pattern in the Fourier plane images, demonstrating that plasmons may be scattered coherently. An analysis of the interference pattern as a function of excitation position on the stripe is used to determine a value of 1.42 ± 0.18 for the relative plasmon wave vector (kSPP/k0) of the corresponding SPPs. From these results, we interpret the directional, large angle (θ~θ(c)) scattering to be mainly from plasmons on the air-gold interface, and the diffuse scattering forming interference fringes to be dominantly from plasmons on the gold-substrate interface.
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Affiliation(s)
- Yang Zhang
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS Université Paris-Sud, Orsay, France
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21
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Dombi P, Hörl A, Rácz P, Márton I, Trügler A, Krenn JR, Hohenester U. Ultrafast strong-field photoemission from plasmonic nanoparticles. Nano Lett 2013; 13:674-8. [PMID: 23339740 PMCID: PMC3573732 DOI: 10.1021/nl304365e] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/08/2013] [Indexed: 05/20/2023]
Abstract
We demonstrate the ultrafast generation of electrons from tailored metallic nanoparticles and unravel the role of plasmonic field enhancement in this process by comparing resonant and off-resonant particles, as well as different particle geometries. We find that electrons become strongly accelerated within the evanescent fields of the plasmonic nanoparticles and escape along straight trajectories with orientations governed by the particle geometry. These results establish plasmonic nanoparticles as versatile ultrafast, nanoscopic sources of electrons.
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Affiliation(s)
- Péter Dombi
- Wigner Research
Centre for Physics, Konkoly-Thege M. út 29-33,
1121 Budapest, Hungary
| | - Anton Hörl
- Institut für Physik, Karl-Franzens Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Péter Rácz
- Wigner Research
Centre for Physics, Konkoly-Thege M. út 29-33,
1121 Budapest, Hungary
| | - István Márton
- Wigner Research
Centre for Physics, Konkoly-Thege M. út 29-33,
1121 Budapest, Hungary
| | - Andreas Trügler
- Institut für Physik, Karl-Franzens Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Joachim R. Krenn
- Institut für Physik, Karl-Franzens Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Ulrich Hohenester
- Institut für Physik, Karl-Franzens Universität
Graz, Universitätsplatz
5, 8010 Graz, Austria
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22
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Tinguely JC, Charron G, Lau-Truong S, Hohenau A, Grand J, Félidj N, Aubard J, Krenn JR. Template-assisted deposition of CTAB-functionalized gold nanoparticles with nanoscale resolution. J Colloid Interface Sci 2013; 394:237-42. [PMID: 23352701 DOI: 10.1016/j.jcis.2012.12.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/20/2012] [Accepted: 12/27/2012] [Indexed: 12/14/2022]
Abstract
In this paper, we demonstrate the template-assisted deposition of cetyltrimethylammonium bromide (CTAB) stabilized gold nanorods at lithographically defined positions on a substrate. Overcoating of the nanoparticles with polystyrenesulfonate allows to switch the original nanoparticles positive surface charge to negative and to apply the template-assisted deposition technique developed for citrate-capped gold nanoparticles also to CTAB stabilized nanoparticles. The successful, selective deposition of gold nanorods in trenches with widths down to 50 nm is demonstrated. Our results indicate the potential of this method for the fabrication of well controlled, reproducible plasmonic biosensing substrates, applicable to the vast palette of anisotropic nanoparticle shapes synthesized with CTAB as the templating agent.
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Affiliation(s)
- Jean-Claude Tinguely
- Institute of Physics, Karl-Franzens University, Universitätsplatz 5, A-8010 Graz, Austria.
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23
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Schmidt FP, Ditlbacher H, Hohenester U, Hohenau A, Hofer F, Krenn JR. Dark plasmonic breathing modes in silver nanodisks. Nano Lett 2012; 12:5780-3. [PMID: 23025804 PMCID: PMC3558010 DOI: 10.1021/nl3030938] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 09/28/2012] [Indexed: 05/19/2023]
Abstract
We map the complete plasmonic spectrum of silver nanodisks by electron energy loss spectroscopy and show that the mode which couples strongest to the electron beam has radial symmetry with no net dipole moment. Therefore, this mode does not couple to light and has escaped from observation in optical experiments. This radial breathing mode has the character of an extended two-dimensional surface plasmon with a wavenumber determined by the circular disk confinement. Its strong near fields can impact the hybridization in coupled plasmonic nanoparticles as well as couplings with nearby quantum emitters.
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Affiliation(s)
- Franz-Philipp Schmidt
- Institute for Electron Microscopy and Fine Structure Research (FELMI), Graz University of Technology, 8010 Graz, Austria.
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24
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Steindorfer MA, Schmidt V, Belegratis M, Stadlober B, Krenn JR. Detailed simulation of structural color generation inspired by the Morpho butterfly. Opt Express 2012; 20:21485-21494. [PMID: 23037268 DOI: 10.1364/oe.20.021485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The brilliancy and variety of structural colors found in nature has become a major scientific topic in recent years. Rapid-prototyping processes enable the fabrication of according structures, but the technical exploitation requires a profound understanding of structural features and material properties regarding the generation of reflected color. This paper presents an extensive simulation of the reflectance spectra of a simplified 2D Morpho butterfly wing model by utilizing the finite-difference time-domain method. The structural parameters are optimized for reflection in a given spectral range. A comparison to simpler models, such as a plane dielectric layer stack, provides an understanding of the origin of the reflection behavior. We find that the wavelength of the reflection maximum is mainly set by the lateral dimensions of the structures. Furthermore small variations of the vertical dimensions leave the spectral position of the reflectance wavelength unchanged, potentially reducing grating effects.
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Affiliation(s)
- Michael A Steindorfer
- Materials - Institute for Surface Technologies and Photonics, Joanneum Research, Franz-Pichler-Straße 30, A-8160 Weiz, Austria.
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25
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Abstract
We launch surface plasmons from one end of a silver nanowire by asymmetric illumination with white light and use plasmon-to-light scattering at the nanowire ends to probe spectroscopically the plasmonic Fabry-Perot wire modes. The spectral positions of the maxima and minima in the scattered intensity from both nanowire ends are found to be either in-phase or out-of-phase, depending on the nanowire length and the spectral range. This behavior can be explained by a generalized Fabry-Perot model. The turnover point between the two regimes is sensitive to the surface plasmon round trip losses and thus opens a new possibility for detecting changes of the optical absorption in the nanowire environment.
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Affiliation(s)
- Andreas Hohenau
- Institute of Physics, Karl-Franzens-University, Graz, Austria. andreas.hohenau@uni‑graz.at
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26
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Abstract
We report on a spectroscopic study of surface plasmon damping and group velocity in polycrystalline silver and gold nanowires. By comparing to single-crystalline wires and by using different substrates, we quantitatively deduce the relative damping contributions due to metal crystallinity and absorption in the substrate. Compared to absorbing substrates, we find strongly reduced plasmonic damping for polycrystalline nanowires on quartz substrates, enabling the application of such wires for plasmonic waveguide networks.
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Affiliation(s)
- Primoz Kusar
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria.
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27
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Abstract
We report on a new biosensor with localized surface plasmons (LSP) based on an array of gold nanorods and the total internal reflection imaging in polarization contrast. The sensitivity of the new biosensor is characterized and a model detection of DNA hybridization is carried out. The results are compared with a reference experiment using a conventional high-resolution surface plasmon resonance (SPR) biosensor. We show that the LSP-based biosensor delivers the same performance as the SPR system while involving significantly lower surface densities of interacting molecules. We demonstrate a limit of detection of 100 pM and a surface density resolution of only 35 fg×mm-2 that corresponds to less than one DNA molecule per nanoparticle on average.
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Affiliation(s)
- Marek Piliarik
- Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, Prague, Czech Republic
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28
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Hohenau A, Krenn JR, Drezet A, Mollet O, Huant S, Genet C, Stein B, Ebbesen TW. Surface plasmon leakage radiation microscopy at the diffraction limit. Opt Express 2011; 19:25749-62. [PMID: 22273967 DOI: 10.1364/oe.19.025749] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper describes the image formation process in optical leakage radiation microscopy of surface plasmon-polaritons with diffraction limited spatial resolution. The comparison of experimentally recorded images with simulations of point-like surface plasmon-polariton emitters allows for an assignment of the observed fringe patterns. A simple formula for the prediction of the fringe periodicity is presented and practically relevant effects of abberations in the imaging system are discussed.
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Affiliation(s)
- A Hohenau
- Institute of Physics, Karl-Franzens University Graz, Universitatsplatz 5,8010 Graz, Austria.
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29
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Piliarik M, Kvasnička P, Galler N, Krenn JR, Homola J. Local refractive index sensitivity of plasmonic nanoparticles. Opt Express 2011; 19:9213-9220. [PMID: 21643175 DOI: 10.1364/oe.19.009213] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report on an experimental characterization of the sensitivity of localized surface plasmons (LSP) to local changes in the refractive index at a nanometer scale. The method is based on forming a polymer mask covering different well defined areas of metallic nanoparticles and measuring the extinction peak shifts associated with the local refractive index changes. Arrays of nanoparticles (nanorod chains) are prepared using electron beam lithography and the dielectric mask is aligned with respect to the nanoparticle array in a second lithographic step. Extinction peak shifts corresponding to different positions of the mask are measured and values for the local refractive index sensitivity are deduced. A deconvolution procedure is established and used to map the local sensitivity across the surface of nanoparticle based on measured data. The experimental results are shown to correspond well with theoretical simulations obtained using the finite-difference time-domain method. The results indicate that the sensitivity is strongly correlated with the profile of the LSP electric field.
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Affiliation(s)
- Marek Piliarik
- Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, Prague, Czech Republic
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30
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Gehan H, Mangeney C, Aubard J, Lévi G, Hohenau A, Krenn JR, Lacaze E, Félidj N. Design and Optical Properties of Active Polymer-Coated Plasmonic Nanostructures. J Phys Chem Lett 2011; 2:926-31. [PMID: 26295630 DOI: 10.1021/jz200272r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The grafting of stimuli-responsive polymer brushes on plasmonic structures provides a perfectly controlled two-dimensional active device with optical properties that can be modified through external stimuli. Herein, we demonstrate thermally induced modifications of the plasmonic response of lithographic gold nanoparticles functionalized by thermosensitive polymer brushes of (poly(N-isopropylacrylamide), PNIPAM). Optical modifications result from refractive local index changes due to a phase transition from a hydrophilic state (swollen regime) to a hydrophobic state (collapsed regime) of the polymer chains occurring in a very small range of temperatures. The refractive index of the polymer in aqueous solution is estimated in both states, deduced from the discrete dipole approximation (DDA) method. The combination of lithographic gold NPs and thermoresponsive polymer chains leads to a new generation of perfectly calibrated and dynamically controlled hybrid gold/polymer system for real-time nanosensors.
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Affiliation(s)
- Hélène Gehan
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Claire Mangeney
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Jean Aubard
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Georges Lévi
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Andreas Hohenau
- ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria
| | - Joachim R Krenn
- ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria
| | - Emmanuelle Lacaze
- §Laboratoire INSP, Université Pierre et Marie Curie, 5 place Jussieu, 75005 Paris, France
| | - Nordin Félidj
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
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31
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Palfinger U, Auner C, Gold H, Haase A, Kraxner J, Haber T, Sezen M, Grogger W, Domann G, Jakopic G, Krenn JR, Stadlober B. Fabrication of n- and p-type organic thin film transistors with minimized gate overlaps by self-aligned nanoimprinting. Adv Mater 2010; 22:5115-5119. [PMID: 20872406 DOI: 10.1002/adma.201001947] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Ursula Palfinger
- Institute of Nanostructured Materials and Photonics, Weiz, Austria
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32
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Koller DM, Hohenester U, Hohenau A, Ditlbacher H, Reil F, Galler N, Aussenegg FR, Leitner A, Trügler A, Krenn JR. Superresolution Moiré mapping of particle plasmon modes. Phys Rev Lett 2010; 104:143901. [PMID: 20481940 DOI: 10.1103/physrevlett.104.143901] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 03/21/2010] [Indexed: 05/29/2023]
Abstract
The spontaneous emission rate of a fluorophore provides a direct probe of the photonic local density of states at the fluorophore position. Here we exploit this capability to map the plasmonic modes of gold nanoparticles by imaging the fluorescence intensity in combined regular arrays of identical gold and fluorophore-doped polymer nanoparticles. By varying the distance between gold and polymer particles across the array, the fluorophore emission generates an optical Moiré pattern corresponding to a magnified spatial map of the plasmonic mode, which can be directly imaged with an optical microscope. Our results are corroborated by supplementary theoretical model calculations.
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Affiliation(s)
- D M Koller
- Institute of Physics and Erwin Schrödinger Institute for Nanoscale Research, Karl-Franzens-University, A-8010 Graz, Austria
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33
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Hohenester U, Ditlbacher H, Krenn JR. Electron-energy-loss spectra of plasmonic nanoparticles. Phys Rev Lett 2009; 103:106801. [PMID: 19792333 DOI: 10.1103/physrevlett.103.106801] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 07/21/2009] [Indexed: 05/21/2023]
Abstract
We investigate electron-energy-loss spectroscopy (EELS) on metallic nanoparticles, through simulations, and provide a comprehensive comparison between EELS and the photonic local density of states (LDOS). Most importantly, we show that there is no direct link between EELS and LDOS maps, and that EELS can even be blind to hot spots in the gap between coupled nanoparticles. Although intimately related, the two quantities provide complementary information. This finding is in marked contrast to recently reported results.
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Affiliation(s)
- Ulrich Hohenester
- Institut für Physik, Karl-Franzens-Universität Graz, Universitätsplatz 5, 8010 Graz, Austria
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34
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Leroux Y, Lacroix JC, Fave C, Stockhausen V, Félidj N, Grand J, Hohenau A, Krenn JR. Active plasmonic devices with anisotropic optical response: a step toward active polarizer. Nano Lett 2009; 9:2144-2148. [PMID: 19361167 DOI: 10.1021/nl900695j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Control of the optical properties of metallic nanoparticles (NP) is realized using an electrochemical switch consisting of a thin layer of conducting polymer (CP). It is shown that the quenching of localized surface plasmon (LSP) sustained by oblate particles depends of the frequency of the LSP resonance. This effect is attributed to the variation of the CP dielectric function with wavelength. As a consequence, prolate arrays show total quenching of the LSP resonance along the major axis of the particles whereas modulation and moderate damping are observed along the minor axis. Combining electroactive conducting polymer and prolate NP makes it possible to design active plasmonic devices with anisotropic optical response upon CP switching. In the present case, such devices can be used as active filters or polarizers.
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Affiliation(s)
- Yann Leroux
- Interfaces, Traitements, Organisation et Dynamique des Systèmes, Université Paris 7-Denis Diderot, UMR 7086, 75205 Paris Cedex 13, France
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35
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Abstract
We show experimentally and numerically that Forster-type resonant energy transfer between molecules strongly depends on the interaction with plasmonic resonances in a nearby metallic nanoparticle (MNP). Acceptor luminescence emerges at the expense of donor luminescence when an acceptor molecule harvests the donor's near-field energy. By tuning the resonance of a close-by MNP across the transition energy bands of the molecules, we show how the molecular luminescence is affected and in part even strongly increased.
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Affiliation(s)
- Frank Reil
- Karl-Franzens Universität Graz, Institut für Physik, Universitätsplatz 5, 8010 Graz, Austria
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36
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Ditlbacher H, Galler N, Koller DM, Hohenau A, Leitner A, Aussenegg FR, Krenn JR. Coupling dielectric waveguide modes to surface plasmon polaritons. Opt Express 2008; 16:10455-64. [PMID: 18607458 DOI: 10.1364/oe.16.010455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We study dielectric/metal thin film multilayers designed for the coupling of dielectric waveguide modes and surface plasmons. The coupling as identified in calculated dispersion relations for extended multilayers is confirmed by measured angle-resolved reflectance data. By lateral structuring of the multilayers the mutual coupling of dielectric and plasmonic modes is directly observed by fluorescence based microscopy. For a light wavelength of 514nm we find a coupling length of 15microm. Our results highlight the potential of hybrid dielectric/metal waveguides for integrating surface plasmon based photonic circuitry or sensing elements into conventional optical devices.
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Affiliation(s)
- H Ditlbacher
- Karl-Franzens University and Erwin Schrödinger Institute for Nanoscale Research, Graz, Austria.
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37
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Leroux Y, Lacroix JC, Fave C, Trippe G, Félidj N, Aubard J, Hohenau A, Krenn JR. Tunable electrochemical switch of the optical properties of metallic nanoparticles. ACS Nano 2008; 2:728-732. [PMID: 19206604 DOI: 10.1021/nn700438a] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Control of the optical properties of oblate metallic nanoparticles (NP) is realized using an electrochemical switch consisting of a thin layer of conducting polymer (CP). Reversible modulation, moderate damping, and almost total quenching of the localized surface plasmon (LSP) resonance is achieved as a function of the thickness of the CP layer and the potential applied to the electrochemical systems, that is, the charge carrier density injected into the CP layer. These experimental results can be qualitatively reproduced using the single-particle model in the electrostatic approximation. We believe that combining an electroactive conducting polymer and NP will prove to be a general strategy for controlling the properties of various types of NP (fluorescent, magnetic, semiconducting) in many fields.
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Affiliation(s)
- Yann Leroux
- Interfaces, Traitement, Organisation et Dynamique des Systemes (ITODYS), Universite Paris 7-Denis Diderot, UMR 7086, 1 rue Guy de la Brosse, 75005 Paris, France
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38
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Abstract
This article reports on the imaging of the surface plasmon fields of lithographically designed micrometre-sized gold structures. We investigate rings made of disk-shaped particles and individual crescent-shaped particles. These structures are imaged with two techniques, dark field imaging of elastically scattered light and imaging the surface-enhanced Raman scattering signal of methylene blue dye adsorbed onto the structures. Although elastically scattered light images result from the coherently summed contributions from all elementary scattering volumes, surface-enhanced Raman scattering images reflect the optical near-field intensity incoherently averaged over a surface area corresponding to the spatial resolution of the microscope objective. The combination of both imaging methods enables us to emphasize the role of plasmon coupling and antenna effect in the surface-enhanced Raman scattering enhancement.
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Affiliation(s)
- G Laurent
- Laboratoire ITODYS, Université Paris 7 - Denis Diderot, CNRS UMR 7086, 1, rue Guy de la Brosse, F-75005 Paris, France
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39
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Baudrion AL, de Léon-Pérez F, Mahboub O, Hohenau A, Ditlbacher H, García-Vidal FJ, Dintinger J, Ebbesen TW, Martin-Moreno L, Krenn JR. Coupling efficiency of light to surface plasmon polariton for single subwavelength holes in a gold film. Opt Express 2008; 16:3420-3429. [PMID: 18542433 DOI: 10.1364/oe.16.003420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The excitation of surface plasmon polaritons (SPP) by focusing a laser beam on single subwavelength holes opened in a thin gold film is studied both experimentally and theoretically. By means of leakage radiation microscopy, quantitative measurements of the light-SPP coupling efficiency are performed for holes with different sizes and shapes. The system is studied theoretically by using a modal expansion method to calculate the fraction of the incident energy which is scattered by the hole into a surface plasmon. We demonstrate that a single subwavelength hole can be used to generate SPP with an efficiency up to 28%.
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Affiliation(s)
- Anne-Laure Baudrion
- Karl-Franzens University and Erwin Schrödinger Institute for Nanoscale Research, A-8010 Graz,
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40
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González MU, Stepanov AL, Weeber JC, Hohenau A, Dereux A, Quidant R, Krenn JR. Analysis of the angular acceptance of surface plasmon Bragg mirrors. Opt Lett 2007; 32:2704-6. [PMID: 17873941 DOI: 10.1364/ol.32.002704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We analyze an important aspect of the behavior of surface plasmon polariton (SPP) Bragg mirrors: the dependence of the angular acceptance for reflection on the incidence angle. By means of leakage radiation microscopy, both in direct and Fourier space, we observe that the angular acceptance diminishes for increasing incidence angles. This effect, which can considerably affect the design of devices based on these elements, is shown to be the consequence of the decrease of the bandgap width with increasing incidence angle.
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Affiliation(s)
- María Ujué González
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860, Castelldefels (Barcelona), Spain.
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41
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Reil F, Gerber S, Krenn JR, Leitner A. Comparing the influence of gold nanorods and -discs on the spontaneous decay rate of Eu–chelate dye. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1464-4258/9/9/s26] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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42
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Hohenau A, Krenn JR, Garcia-Vidal FJ, Rodrigo SG, Martin-Moreno L, Beermann J, Bozhevolnyi SI. Comparison of finite-difference time-domain simulations and experiments on the optical properties of gold nanoparticle arrays on gold film. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1464-4258/9/9/s14] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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43
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Drezet A, Koller D, Hohenau A, Leitner A, Aussenegg FR, Krenn JR. Surface plasmon polariton microscope with parabolic reflectors. Opt Lett 2007; 32:2414-6. [PMID: 17700803 DOI: 10.1364/ol.32.002414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We report the realization of a two-dimensional optical microscope for surface plasmons polaritons (SPPs) based on parabolic Bragg mirrors. These mirrors are built from lithographically fabricated gold nanostructures on gold thin films. We show by direct imaging by leakage radiation microscopy that the magnification power of the SPP microscope follows basic predictions of geometrical optics. Spatial resolution down to the value set by the diffraction limit is demonstrated.
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Affiliation(s)
- Aurelien Drezet
- Institute of Physics and Erwin Schrödinger, Institute for Nanoscale Research, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria.
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Abstract
We present an overview of recent progress in "plasmonics". We focus our study on the observation and excitation of surface plasmon polaritons (SPPs) with optical near-field microscopy. We discuss in particular recent applications of photon scanning tunnelling microscope (PSTM) for imaging of SPP propagating in metal and dielectric wave guides. We show how near-field scanning optical microscopy (NSOM) can be used to optically and actively address remote nano objects such as quantum dots. Additionally we compare results obtained with near-field microcopy to those obtained with other optical far-field methods of analysis such as leakage radiation microscopy (LRM).
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Affiliation(s)
- A Drezet
- Institute of Physics, Karl-Franzens University Graz, Universitätsplatz 5, A-8010 Graz, Austria.
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45
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Abstract
We report the realization of two-dimensional optical wavelength demultiplexers and multiports for surface plasmons polaritons (SPPs) based on plasmonic crystals, i.e., photonic crystals for SPPs. These SPP elements are built up of lithographically fabricated gold nanostructures on gold thin films. We show by direct imaging of laterally confined SPP beams in the visible spectral range by leakage radiation microscopy that SPPs of different wavelengths are efficiently rerouted into different directions. In addition we demonstrate the generation of three output SPP beams from one input beam.
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Affiliation(s)
- A Drezet
- Institute of Physics, Karl-Franzens-University, Universitätsplatz 5, 8010 Graz, Austria.
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46
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Drezet A, Hohenau A, Krenn JR. Comment on "far-field optical microscopy with a nanometer-scale resolution based on the in-plane image magnification by surface plasmon polaritons". Phys Rev Lett 2007; 98:209703; discussion 209704. [PMID: 17677749 DOI: 10.1103/physrevlett.98.209703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Indexed: 05/16/2023]
Affiliation(s)
- Aurélien Drezet
- Institute of Physics Karl-Franzens University Universitätsplatz 5, A-8010 Graz, Austria.
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47
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Kiyan R, Reinhardt C, Passinger S, Stepanov AL, Hohenau A, Krenn JR, Chichkov BN. Rapid prototyping of optical components for surface plasmon polaritons. Opt Express 2007; 15:4205-4215. [PMID: 19532665 DOI: 10.1364/oe.15.004205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Advanced femtosecond laser technology allows the fabrication of arbitrary 2D and 3D dielectric micro- and nanoscale structures by two-photon polymerization (2PP). In this paper, we present first investigations on excitation of surface plasmon polaritons (SPPs) on dielectric 2D structures fabricated on metal surfaces with this technology. Straight and curved line- and dot- structures built of the negative-tone photoresist ORMOCER (organically modified ceramic) are investigated by plasmon leakage radiation microscopy. Polarization dependent excitation efficiencies and focusing of SPPs are investigated.
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48
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Koller G, Berkebile S, Krenn JR, Netzer FP, Oehzelt M, Haber T, Resel R, Ramsey MG. Heteroepitaxy of organic-organic nanostructures. Nano Lett 2006; 6:1207-12. [PMID: 16771581 DOI: 10.1021/nl060629l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Highly crystalline organic heteroepitaxial layers with controlled molecular orientations and morphologies are one of the keys for optimum organic device performance. With studies of molecular orientation, structure, and morphology, we have investigated the ability of oriented organic films to act as substrate templates for the growth of a second organic layer. Depending on the molecular orientation in the sexiphenyl substrate, crystalline sexithiophene nanostructures of either pyramidal or needlelike morphology, with either near vertical or parallel molecular orientations, respectively, grow.
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Affiliation(s)
- Georg Koller
- Institute of Physics, Karl-Franzens-University, Universitaetsplatz 5, A-8010 Graz, Austria.
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49
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Ditlbacher H, Hohenau A, Wagner D, Kreibig U, Rogers M, Hofer F, Aussenegg FR, Krenn JR. Silver nanowires as surface plasmon resonators. Phys Rev Lett 2005; 95:257403. [PMID: 16384506 DOI: 10.1103/physrevlett.95.257403] [Citation(s) in RCA: 435] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Indexed: 05/05/2023]
Abstract
We report on chemically prepared silver nanowires (diameters around 100 nm) sustaining surface plasmon modes with wavelengths shortened to about half the value of the exciting light. As we find by scattered light spectroscopy and near-field optical microscopy, the nonradiating character of these modes together with minimized damping due to the well developed wire crystal structure gives rise to large values of surface plasmon propagation length and nanowire end face reflectivity of about 10 microm and 25%, respectively. We demonstrate that these properties allow us to apply the nanowires as efficient surface plasmon Fabry-Perot resonators.
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50
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Félidj N, Laurent G, Aubard J, Lévi G, Hohenau A, Krenn JR, Aussenegg FR. Grating-induced plasmon mode in gold nanoparticle arrays. J Chem Phys 2005; 123:221103. [PMID: 16375460 DOI: 10.1063/1.2140699] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We study the dipolar coupling of gold nanoparticles arranged in regular two-dimensional arrays by extinction micro-spectroscopy. When the interparticle spacing approaches the plasmon resonance wavelength of the individual particles, an additional band of very narrow width emerges in the extinction spectrum. By systematically changing the particles dielectric environment, the particles shape, the grating constant and angle of incidence, we show how this band associated to a grating induced-resonance can be influenced in strength and spectral position. The spectral position can be qualitatively understood by considering the conditions for grazing grating orders whereas the strength can be related to the strength of dipolar scattering from the individual particles.
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Affiliation(s)
- N Félidj
- Laboratoire ITODYS, Université Paris 7-Denis Diderot, CNRS UMR 7086, 1 rue Guy de la Brosse, F-75005 Paris, France.
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