Filters

2019 - 20202

More filters

Show more
Reset filters

Settings

search.filters.applied.f.access: openAccess × Author: Gupta, Vaibhav × DDC: 540 × DDC: 600 × Type: Article × WGL Institute: IPF ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Hybridized Guided-Mode Resonances via Colloidal Plasmonic Self-Assembled Grating
    (Washington, DC : Soc., 2019) Sarkar, Swagato; Gupta, Vaibhav; Kumar, Mohit; Schubert, Jonas; Probst, Patrick T.; Joseph, Joby; König, Tobias A.F.
    For many photonic applications, it is important to confine light of a specific wavelength at a certain volume of interest at low losses. So far, it is only possible to use the polarized light perpendicular to the solid grid lines to excite waveguide-plasmon polaritons in a waveguide-supported hybrid structure. In our work, we use a plasmonic grating fabricated by colloidal self-assembly and an ultrathin injection layer to guide the resonant modes selectively. We use gold nanoparticles self-assembled in a linear template on a titanium dioxide (TiO 2 ) layer to study the dispersion relation with conventional ultraviolet-visible-near-infrared spectroscopic methods. Supported with finite-difference in time-domain simulations, we identify the optical band gaps as hybridized modes: plasmonic and photonic resonances. Compared to metallic grids, the observation range of hybridized guided modes can now be extended to modes along the nanoparticle chain lines. With future applications in energy conversion and optical filters employing these cost-efficient and upscalable directed self-assembly methods, we discuss also the application in refractive index sensing of the particle-based hybridized guided modes. Copyright © 2019 American Chemical Society.
  • Thumbnail Image
    Item
    Mechanotunable Plasmonic Properties of Colloidal Assemblies
    (Weinheim : Wiley-VCH, 2020) Brasse, Yannic; Gupta, Vaibhav; Schollbach, H.C. Tomohiro; Karg, Matthias; König, Tobias A.F.; Fery, Andreas
    Noble metal nanoparticles can absorb incident light very efficiently due to their ability to support localized surface plasmon resonances (LSPRs), collective oscillations of the free electron cloud. LSPRs lead to strong, nanoscale confinement of electromagnetic energy which facilitates applications in many fields including sensing, photonics, or catalysis. In these applications, damping of the LSPR caused by inter- and intraband transitions is a limiting factor due to the associated energy losses and line broadening. The losses and broad linewidth can be mitigated by arranging the particles into periodic lattices. Recent advances in particle synthesis, (self-)assembly, and fabrication techniques allow for the realization of collective coupling effects building on various particle sizes, geometries, and compositions. Beyond assemblies on static substrates, by assembling or printing on mechanically deformable surfaces a modulation of the lattice periodicity is possible. This enables significant alteration and tuning of the optical properties. This progress report focuses on this novel approach for tunable spectroscopic properties with a particular focus on low-cost and large-area fabrication techniques for functional plasmonic lattices. The report concludes with a discussion of the perspectives for expanding the mechanotunable colloidal concept to responsive structures and flexible devices. © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim