Near-field optics and nano-optics

11:00 Invited talk : Drawn THz Hyperlenses - Focusing, Magnication and Artefacts

Boris T. Kuhlmey, A. Tuniz, J. Anthony, X. Tang, S. Fleming, A. Argyros

University of Sydney (Australia)

The fibre drawing technique lends itself well to fabrication of large scale hyperlenses for the THz spectrum and beyond. Here we demonstrate magnification by a factor 8 enabling far-field imaging of sub-diffraction details. However not all components of the near field can be imaged through hyperlenses. We discuss what hyperlenses actually image, and artefacts arising from the coupling to diffracting ordinary waves.
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11:20 : Solid-Immersion Microsphere Superlens

Zengbo Wang (1),Bing Yan (1),Liyang Yue (1),Richard Leach (2),Boris Luk'yanchuk (3)

(1)Bangor University (United Kingdom) , (2)University of Nottingham (United Kingdom) , (3)Data Storage Institute (Singapore)

In 2011, we demonstrated the first 50 nm resolution white-light nanoscope based on a microsphere superlens. Here, we present a new generation design of microsphere superlens: the Solid-Immersion Microsphere Superlens (SIMS), which features higher resolution and flexible maneuverability over the previous design.
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11:35 : THz streaking at metal nanotips

Lara Wimmer, Georg Herink, Katharina E. Echternkamp, Sergey Yalunin, Claus Ropers

University of Gottingen (Germany)

We present a streaking-type experiment at single metal nanotips using femtosecond near-infrared pulses and ultrashort terahertz transients. The nanometric confinement and enhancement of the terahertz (THz) near-field lead to characteristic streaking spectrograms resulting from quasi-instantaneous photoelectron acceleration. Our setup enables a phase-resolved measurement of the THz near-field transient, a reshaping of photoelectron energy spectra and the observation of hot carrier dynamics excited in the tip probed by field-induced tunneling.
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11:50 : Superlocalization of Brownian Nanoparticles by Holography for 3D Stochastic Optical Mapping

Gilles Tessier (1),Ariadna Martinez-Marrades (1),Jean-François Rupprecht (2)

(1)Institut Langevin ESPCI (France) , (2)UPMC (France)

We present a wide field microscopy technique for the 3D mapping of optical intensity using Brownian gold nanoparticles as local probes. Localization by off-axis holography allows stochastic subwavelength optical characterization in water-based systems.
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12:05 : All-dielectric nanoparticle array waveguides

Roman Savelev (1),Dmitry Filonov (1),Alexander Krasnok (1),Polina Kapitanova (1),Andrey Miroshnichenko (2),Pavel Belov (1),Yuri Kivshar (2)

(1)ITMO University (Russia) , (2)Australian National University (Australia)

We propose a novel approach for realizing subwavelength waveguides based on chains of high-index dielectric nanoparticles with both electric and magnetic dipole resonances. We reveal that the electromagnetic energy can be efficiently guided by chain of dielectric nanoparticles even through sharp bends and defects. We confirm experimentally the main concept and our theoretical findings in the microwave frequency range.
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12:20 : Terahertz nonlinear transmission studies on ultra-long nanogaps of thin-film aluminium oxide

Joon-Yeon Kim (1),Bong Ju Kang (2),Won Tae Kim (2),Joohyun Park (3),Young-Mi Bahk (1),Jiyeah Rhie (1),Hyeongtag Jeon (3),Fabian Rotermund (2),Dai-Sik Kim (1)

(1)Seoul National University (Korea) , (2)Ajou University (Korea) , (3)Hanyang University (Korea)

We demonstrate a nonlinear response at nanometer-sized gaps by applying intense terahertz fields. We estimate that fields of over 10 MV/cm can be achieved inside the nanogaps, leading to a giant nonlinearity of the thin insulating layer of aluminium oxide that forms the nanogap. Due to the single-cycle nature of terahertz pulses, peak voltages as high as over 10 V across a 10-nm gap is maintained during a sub-picosecond period of time.
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