The Experts below are selected from a list of 12186 Experts worldwide ranked by ideXlab platform
H Kurz - One of the best experts on this subject based on the ideXlab platform.
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tapered photoconductive terahertz field Probe Tip with subwavelength spatial resolution
Applied Physics Letters, 2009Co-Authors: Markus Wachter, M Nagel, H KurzAbstract:In this work a photoconductive Probe Tip applicable for near- and far-field measurements in the terahertz frequency regime is demonstrated as a powerful alternative to existing terahertz scanning near-field optical microscopy approaches. The Probe Tip is based on a triangular-shaped patch of freestanding low-temperature-grown GaAs of only 1.3 μm thickness with a pair of tapered metallic wires on top. Using nonresonant electric field enhancement at the Tip of the probing device, 10 μm wide metallic structures are spatially resolved and a bandwidth of 2 THz is demonstrated.
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Free-standing tapered Probe-Tip for high resolution photoconductive terahertz field sampling
2009 34th International Conference on Infrared Millimeter and Terahertz Waves, 2009Co-Authors: Markus Wachter, M Nagel, H KurzAbstract:We present a photoconductive Probe-Tip applicable for near- and far-field measurements in the terahertz frequency range. The Probe-Tip is based on a triangular patch of freestanding LT-GaAs of only 1.3 mum thickness with a pair of tapered metallic wires on top. Using non-resonant electric field enhancement at the Tip of the probing device a spatial resolution of 5 mum and a bandwidth of 2 THz is demonstrated.
Hartmut G Roskos - One of the best experts on this subject based on the ideXlab platform.
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anisotropic excitation of surface plasmon polaritons on a metal film by a scattering type scanning near field microscope with a non rotationally symmetric Probe Tip
Nanophotonics, 2018Co-Authors: Frederik Walla, Matthias M Wiecha, Nicolas Mecklenbeck, Sabri Beldi, Fritz Keilmann, Mark D Thomson, Hartmut G RoskosAbstract:We investigated the excitation of surface plasmon polaritons on gold films with the metallized Probe Tip of a scattering-type scanning near-field optical microscope (s-SNOM). The emission of the polaritons from the Tip, illuminated by near-infrared laser radiation, was found to be anisotropic and not circularly symmetric as expected on the basis of literature data. We furthermore identified an additional excitation channel via light that was reflected off the Tip and excited the plasmon polaritons at the edge of the metal film. Our results, while obtained for a non-rotationally-symmetric type of Probe Tip and thus specific for this situation, indicate that when an s-SNOM is employed for the investigation of plasmonic structures, the unintentional excitation of surface waves and anisotropic surface wave propagation must be considered in order to correctly interpret the signatures of plasmon polariton generation and propagation.
Markus Wachter - One of the best experts on this subject based on the ideXlab platform.
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tapered photoconductive terahertz field Probe Tip with subwavelength spatial resolution
Applied Physics Letters, 2009Co-Authors: Markus Wachter, M Nagel, H KurzAbstract:In this work a photoconductive Probe Tip applicable for near- and far-field measurements in the terahertz frequency regime is demonstrated as a powerful alternative to existing terahertz scanning near-field optical microscopy approaches. The Probe Tip is based on a triangular-shaped patch of freestanding low-temperature-grown GaAs of only 1.3 μm thickness with a pair of tapered metallic wires on top. Using nonresonant electric field enhancement at the Tip of the probing device, 10 μm wide metallic structures are spatially resolved and a bandwidth of 2 THz is demonstrated.
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Free-standing tapered Probe-Tip for high resolution photoconductive terahertz field sampling
2009 34th International Conference on Infrared Millimeter and Terahertz Waves, 2009Co-Authors: Markus Wachter, M Nagel, H KurzAbstract:We present a photoconductive Probe-Tip applicable for near- and far-field measurements in the terahertz frequency range. The Probe-Tip is based on a triangular patch of freestanding LT-GaAs of only 1.3 mum thickness with a pair of tapered metallic wires on top. Using non-resonant electric field enhancement at the Tip of the probing device a spatial resolution of 5 mum and a bandwidth of 2 THz is demonstrated.
Frederik Walla - One of the best experts on this subject based on the ideXlab platform.
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anisotropic excitation of surface plasmon polaritons on a metal film by a scattering type scanning near field microscope with a non rotationally symmetric Probe Tip
Nanophotonics, 2018Co-Authors: Frederik Walla, Matthias M Wiecha, Nicolas Mecklenbeck, Sabri Beldi, Fritz Keilmann, Mark D Thomson, Hartmut G RoskosAbstract:We investigated the excitation of surface plasmon polaritons on gold films with the metallized Probe Tip of a scattering-type scanning near-field optical microscope (s-SNOM). The emission of the polaritons from the Tip, illuminated by near-infrared laser radiation, was found to be anisotropic and not circularly symmetric as expected on the basis of literature data. We furthermore identified an additional excitation channel via light that was reflected off the Tip and excited the plasmon polaritons at the edge of the metal film. Our results, while obtained for a non-rotationally-symmetric type of Probe Tip and thus specific for this situation, indicate that when an s-SNOM is employed for the investigation of plasmonic structures, the unintentional excitation of surface waves and anisotropic surface wave propagation must be considered in order to correctly interpret the signatures of plasmon polariton generation and propagation.
Tatsuhiko Sugiyama - One of the best experts on this subject based on the ideXlab platform.
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Strongly Localized and Strongly Enhanced Optical Near-Field Created by Surface Plasmon Polaritons and its Application in Nano-Phtonics
2006 International Conference on Mathematical Methods in Electromagnetic Theory, 2006Co-Authors: Kazuo Tanaka, Masahiro Tanaka, Tatsuhiko SugiyamaAbstract:A metallic Probe that provides a strongly localized and strongly enhanced optical near-field at the Probe-Tip has been investigated. Since the Probe-Tip is illuminated by SPPs inside the aperture, illumination by an external light is not necessary for this Probe. It was found that the Probe can create an optical near-field intensity that is about 103 times larger than the incident intensity on the Probe-Tip, when appropriate parameters of the Probe are used. The imaging simulation of a nanometric dielectric object by near-field scanning optical microscope (NSOM) using plasmonic gap Probe proposed have been performed. Since the localization and enhancement of the optical near-field on the Probe-Tip is related to the propagation of SPPs in the nanometric gap inside the aperture and pyramidal structure, the phenomena investigated in this study are not simple. From our experience of numerical simulations, results are very sensitive to the various parameters of the aperture, demonstrating the need to develop accurate computer-aided design and simulation tools for the design of the Probe
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Creation of strongly localized and strongly enhanced optical near-field on metallic Probe-Tip with surface plasmon polaritons
Optics Express, 2006Co-Authors: Kazuo Tanaka, Masahiro Tanaka, Tatsuhiko SugiyamaAbstract:A practical technique by which a strongly confined and strongly enhanced optical near-field can be created on a metallic Probe-Tip is investigated. The technique uses an I-shaped aperture in a pyramidal structure formed on a thick metallic screen. The pyramidal structure divided into two sections by the I-shaped aperture and one of them is used as a tapered metallic Probe. A surface plasmon polariton (SPP), which is excited and enhanced in the I-shaped aperture, propagates along the side surface of the aperture and pyramidal structure and illuminate the Probe-Tip. Scattering of optical waves by this structure is solved numerically using a volume integral equation by a generalized minimum residual method and fast Fourier transformation. It is shown that a strongly localized and strongly enhanced optical field is created at the Tip of this metallic Probe by SPPs. The fundamental characteristics of the localized and enhanced optical near-field on the Probe-Tip are investigated.
