Session Overview |
Nonlinear Optics, Nanophotonics and Plasmonics - Bloc 4Room: Cartier 2 |
Date: Thursday, June 07 |
08:15 |
Harmonic generation from metal-metal and metal-oxide boundaries
Main Author: Michael Scalora Organization: Charles M. Bowden Research Center U.S. Army AMRDEC, RDECOM, United States We study harmonic generation that arises from surfaces that demarcate regions of discontinuous free-electron densities. These circumstances can occur in structures consisting of a simple metal mirror, or arrangements composed of either different metals or a metal and a conducting oxide. Using a hydrodynamic approach we highlight the case of a gold mirror, and a two-layer system containing indium tin oxide (ITO) and gold. We assume the gold mirror surface is characterized by a free-electron cloud of varying density that spills into the vacuum, which as a result of material dispersion exhibits epsilon-near-zero conditions and consequential local field enhancement at the surface. For thin ITO and gold bilayers, if the wave is incident from the ITO side the electromagnetic field is presented with a free-electron discontinuity at the ITO/gold interface, and wavelength-dependent, epsilon-near-zero conditions that can significantly enhance local fields and conversion efficiencies, and thus determine the surface’s emission properties. We evaluate the relative significance of additional nonlinear sources that arise when a free-electron discontinuity is present, and show that harmonic generation can be sensitive to the density of the free-electron cloud, and not its thickness. Our findings suggest the possibility to control surface harmonic generation through surface charge engineering. |
08:40 |
Dual-probe SNOM for the near-field study of nanostructures
Main Author: Najmeh Abbasirad Organization: Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, Germany We employed the automated dual-probe scanning near-field optical microscope to study the wave propagation length along nanodiscs arrays and intensity distribution of localizations along disordered nanodiscs |
08:55 |
Tunable Longitudinal Modes in Self-Assembled Silver Nanoparticles
Main Author: Amy Blum Organization: McGill University, Canada We demonstrate that 14-nm silver nanoparticles can be quickly and spontaneously self-assembled into highly anisotropic structures in solution using controlled amounts of one of three short ditopic ligands: cysteamine, DTT or cysteine. The self-assembled chain-based structures are bound together through hydrogen bonding, making them reasonably robust over a wide range of solution conditions and temperatures. The degree of self-assembly, and thus the resulting optical properties can be readily and reproducibly dictated by the ligand concentration, pH and solvent. The highly anisotropic spectra are reminiscent of high aspect ratio 1D nanoparticles such as rods, and have not been previously demonstrated to this extent with silver nanoparticles. |
09:10 |
Ultra-high quality factor plasmonic metasurfaces enabled by surface lattice resonances
Main Author: Md Saad-Bin-Alam Organization: University of Ottawa, Canada Plasmonic metasurfaces consisting of periodically arranged metamolecules could become a promising platform for strong light-matter interactions. However, due to the high absorption loss of noble metals, the localized surface plasmon resonances (LSPR) of individual metamolecules exhibit very low quality factors (Q ~ order of 10). In our study, we use full-wave simulations to design ultra-high Q-factor (>~104) surface lattice resonances (SLRs) around the wavelength of 1550 nm by optimizing the LSPR of rectangular gold metamolecules. Due to their ease of fabrication, these ultra-high-Q metasurfaces will enable the exploration of many new applications in the study of nanophotonics. |
09:25 |
Machine Learning Applications in Plasmonics
Main Author: Josh Baxter Organization: Department of Physics and Center for Research in Photonics, University of Ottawa , Canada The abundance of acquired data from experiments and simulations makes the field of photonics a perfect environment for machine learning applications. Here we will apply machine learning algorithms to predict the colour of nano-structured surfaces using either the nanoparticle geometric parameters, or laser parameters used to develop the nano-structured surfaces. |
09:40 |
Regularized quasinormal modes for plasmonics and cavity photonics
Main Author: Mohsen Kamandar Dezfouli Organization: Queen's University, Canada We present a new FDTD method of calculating open system cavity modes – termed quasinormal modes (QNMs) - for arbitrary shaped resonators and cavities in plasmonics and photonics. Our technique uses the widely adopted FDTD solver and requires no spatial integration for the normalization of the modal fields. We exemplify the use of these QNMs by studying the generalized Purcell factor of quantum emitters coupled to metallic nanoresonators, hybrid metal-dielectric devices, as well as photonic crystal coupled-cavity waveguides. We also compare our results with full-dipole simulations of Maxwell's equations and show excellent agreement. |
09:55 |
High-performance Optoelectronic and Nanophotonic Devices Enabled by Ultra-thin, Smooth, and Low-loss Doped Silver
Main Author: Cheng Zhang Organization: Center for Nanoscale Science and Technology, National Institute of Standards and Technology, United States We present a new plasmonic material termed ‘doped Ag’, and its applications in various optoelectronic and nanophotonic devices with improved performance, including hyperbolic metamaterials, plasmonic interconnects, organic solar cells, and polymer light emitting diodes. |
10:10 |
Topological phenomena in plasmonic arrays of interacting metallic nanoparticles
Main Author: Guillaume Weick Organization: Université de Strasbourg, CNRS, France Metallic nanoparticles host collective bosonic excitations, called localized surface plasmons. The latter are dipolar in nature and correspond to an oscillation of the electronic center of mass. In arrays of plasmonic nanoparticles, the localized surface plasmons hybridize to form extended collective modes due to dipolar interactions. In this talk, I will discuss the properties of such collective modes in one- and two-dimensional topological plasmonic metamaterials. In particular, I will discuss the nontrivial topological properties of dimerized chains [1], as well as honeycomb lattices of metallic nanoparticles [2, 3], which are the host of chiral Dirac-like plasmonic excitations. [1] C.A. Downing, G. Weick, "Topological collective plasmons in bipartite chains of metallic nanoparticles", Phys. Rev. B 95, 125426 (2017). [2] G. Weick, C. Woollacott, W.L. Barnes, O. Hess, E. Mariani, "Dirac-like plasmons in honeycomb lattices of metallic nanoparticles", Phys. Rev. Lett. 110, 106801 (2013). [3] C.-R. Mann, T.J. Sturges, G. Weick, W.L. Barnes, E. Mariani, "Unconventional Dirac polaritons in cavity-embedded honeycomb metasurfaces", arXiv:1707.04503. |