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DDC: 530 × Subject: Plasmonics ×

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Now showing 1 - 6 of 6
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    Hybrid Optical Fibers – An Innovative Platform for In‐Fiber Photonic Devices
    (Weinheim : Wiley-VCH, 2015) Alexander Schmidt, Markus; Argyros, Alexander; Sorin, Fabien
    The field of hybrid optical fibers is one of the most active research areas in current fiber optics and has the vision of integrating sophisticated materials inside fibers, which are not traditionally used in fiber optics. Novel in-fiber devices with unique properties have been developed, opening up new directions for fiber optics in fields of critical interest in modern research, such as biophotonics, environmental science, optoelectronics, metamaterials, remote sensing, medicine, or quantum optics. Here the recent progress in the field of hybrid optical fibers is reviewed from an application perspective, focusing on fiber-integrated devices enabled by including novel materials inside polymer and glass fibers. The topics discussed range from nanowire-based plasmonics and hyperlenses, to integrated semiconductor devices such as optoelectronic detectors, and intense light generation unlocked by highly nonlinear hybrid waveguides.
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    Scanning single quantum emitter fluorescence lifetime imaging: Quantitative analysis of the local density of photonic states
    (Washington, DC : American Chemical Society, 2014) Schell, A.W.; Engel, P.; Werra, J.F.M.; Wolff, C.; Busch, K.; Benson, O.
    Their intrinsic properties render single quantum systems as ideal tools for quantum enhanced sensing and microscopy. As an additional benefit, their size is typically on an atomic scale that enables sensing with very high spatial resolution. Here, we report on utilizing a single nitrogen vacancy center in nanodiamond for performing three-dimensional scanning-probe fluorescence lifetime imaging microscopy. By measuring changes of the single emitter's lifetime, information on the local density of optical states is acquired at the nanoscale. Three-dimensional ab initio discontinuous Galerkin time-domain simulations are used in order to verify the results and to obtain additional insights. This combination of experiment and simulations to gather quantitative information on the local density of optical states is of direct relevance for the understanding of fundamental quantum optical processes as well as for the engineering of novel photonic and plasmonic devices.
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    Importance of substrates for the visibility of "dark" plasmonic modes
    (Washington, DC : Soc., 2020) Fiedler, Saskia; Raza, Søren; Ai, Ruoqi; Wang, Jianfang; Busch, Kurt; Stenger, Nicolas; Mortensen, N. Asger; Wolff, Christian
    Dark plasmonic modes have interesting properties, including longer lifetimes and narrower linewidths than their radiative counterpart, and little to no radiative losses. However, they have not been extensively studied yet due to their optical inaccessibility. In this work, we systematically investigated the dark radial breathing modes (RBMs) in monocrystalline gold nanodisks, specifically their outcoupling behavior into the far-field by cathodoluminescence spectroscopy. Increasing the substrate thickness resulted in an up to 4-fold enhanced visibility. This is attributed to breaking the mirror symmetry by the high-index substrate, creating an effective dipole moment. Furthermore, the resonance energy of the dark RMBs can be easily tuned by varying the nanodisk diameter, making them promising candidates for nanophotonic applications. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
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    Interfacing optical fibers with plasmonic nanoconcentrators
    (Berlin : de Gruyter, 2018) Tuniz, Alessandro; Schmidt, Markus A.
    The concentration of light to deep-subwavelength dimensions plays a key role in nanophotonics and has the potential to bring major breakthroughs in fields demanding to understand and initiate interaction on nanoscale dimensions, including molecular disease diagnostics, DNA sequencing, single nanoparticle manipulation and characterization, and semiconductor inspection. Although planar metallic nanostructures provide a pathway to nanoconcentration of electromagnetic fields, the delivery/collection of light to/from such plasmonic nanostructures is often inefficient, narrow-band, and requires complicated excitations schemes, limiting widespread applications. Moreover, planar photonic devices reveal a reduced flexibility in terms of bringing the probe light to the sample. An ideal photonic-plasmonic device should combine (i) a high spatial resolution at the nanometre level beyond to what is state-of-the-art in near-field microscopy with (ii) flexible optical fibers to promote a straightforward integration into current near-field scanning microscopes. Here, we review the recent development and main achievements of nanoconcentrators interfacing optical fibers at their end-faces that reach entirely monolithic designs, including campanile probes, gold-coated fiber-taper nanotips, and fiber-integrated gold nanowires.
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    Driving plasmonic nanoantennas at perfect impedance matching using generalized coherent perfect absorption
    (Berlin : de Gruyter, 2021) Grimm, Philipp; Razinskas, Gary; Huang, Jer-Shing; Hecht, Bert
    Coherent perfect absorption (CPA) describes the absence of all outgoing modes from a lossy resonator, driven by lossless incoming modes. Here, we show that for nanoresonators that also exhibit radiative losses, e.g., plasmonic nanoantennas, a generalized version of CPA (gCPA) can be applied. In gCPA outgoing modes are suppressed only for a subset of (guided plasmonic) modes while other (radiative) modes are treated as additional loss channels - a situation typically referred to as perfect impedance matching. Here we make use of gCPA to show how to achieve perfect impedance matching between a single nanowire plasmonic waveguide and a plasmonic nanoantenna. Antennas with both radiant and subradiant characteristics are considered. We further demonstrate potential applications in background-free sensing.
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    Ultrafast nonlocal collective dynamics of Kane plasmon-polaritons in a narrow-gap semiconductor
    (Washington : American Association for the Advancement of Science (A A A S), 2019) Charnukha, A.; Sternbach, A.; Stinson, H.T.; Schlereth, R.; Brüne, C.; Molenkamp, L.W.; Basov, D.N.
    The observation of ultrarelativistic fermions in condensed-matter systems has uncovered a cornucopia of novel phenomenology as well as a potential for effective ultrafast light engineering of new states of matter. While the nonequilibrium properties of two- and three-dimensional (2D and 3D) hexagonal crystals have been studied extensively, our understanding of the photoinduced dynamics in 3D single-valley ultrarelativistic materials is, unexpectedly, lacking. Here, we use ultrafast scanning near-field optical spectroscopy to access and control nonequilibrium large-momentum plasmon-polaritons in thin films of a prototypical narrow-bandgap semiconductor Hg0.81Cd0.19Te. We demonstrate that these collective excitations exhibit distinctly nonclassical scaling with electron density characteristic of the ultrarelativistic Kane regime and experience ultrafast initial relaxation followed by a long-lived highly coherent state. Our observation and ultrafast control of Kane plasmon-polaritons in a semiconducting material using light sources in the standard telecommunications fiber-optics window open a new avenue toward high-bandwidth coherent information processing in next-generation plasmonic circuits.