8:00 am – 9:30 am
Part I: Andrea Alù
Tailoring Optical Wavefronts with Metasurfaces
Metamaterials are artificial materials with properties well beyond what is offered by nature, providing unprecedented opportunities to tailor and enhance the interaction between waves with materials. Metasurfaces are the 2D, planarized version of metamaterials, particularly well suited for nano-optics implementation and integration. In this tutorial, I discuss our recent research activity in electromagnetics, nano-optics and nanophotonics, showing how suitably tailored meta-atoms and arrangements of them open exciting venues to manipulate and control waves in unprecedented ways over a surface. I will discuss our recent theoretical and experimental results, including metamaterials for scattering suppression, nanostructures and metasurfaces to control wave propagation and radiation, giant nonlinearities in properly tailored metamaterials, enhanced large light–matter interactions, and parity-time symmetric meta-atoms and metasurfaces. Physical insights into these exotic phenomena, new devices based on these concepts and their impact on technology and nanophotonics will be discussed during the tutorial.
10:00 am – 10:30 am BREAK
10:30 am – 12:00 pm
Part II: Dragomir Neshev
Dielectric Metasurfaces for Manipulation of Classical and Quantum Light
Ultra-thin dielectric nanocrystals ordered in a metasurface can enable efficient manipulation of light properties, including phase, amplitude and polarisation through the excitation of Mie-type modes in the nanocrystals. Importantly, such resonant metasurfaces can also dramatically enhance light–matter interaction, enabling efficient nonlinear wave-mixing, including second-harmonic generation and spontaneous parametric down conversion. This lecture will overview the fundamental designs and principles of operation of such dielectric metasurfaces, as well as the plethora of their functionalities and applications. In particular, I will show their use in efficient beam shaping and holograms, as well as some of their recent applications in nonlinear light sources, biosensing and characterisation of multi-photon entangled states.
12:00 pm – 1:30 pm BREAK
1:30 pm – 3:00 pm
Part III: Cherie R. Kagan
Building Optical Metamaterials from Plasmonic Nanocrystal Building Blocks
This tutorial will present the design, synthesis and optical properties of metamaterials constructed from colloidal, plasmonic nanocrystals (NCs). Plasmonic NCs are characterized by their localized surface plasmon resonances (LSPRs). Advances in synthetic methods are used to prepare colloidal noble metal and highly doped semiconductor NCs. Tailoring the NC size, shape and composition at the atomic and nanoscales provides control over the spectral position, across the visible to infrared, and width of their LSPRs and the spatial distribution of their electric fields. These colloidal plasmonic NCs may be used as building blocks for the self- or directed-assembly of NC metamaterials from a single type or from a combination of two or even three types of NCs. The optical properties of these NC metamaterials evolve at the mesoscale and depend on the number, type and arrangement of the NCs and the strength of their coupling. The coupling between NCs may be tailored by the length and composition of ligands at the NC surface and enable the design of NC-based materials with optical properties not found in analogous bulk materials. These NC assemblies may be exploited for the unique optical and multifunctional properties. Lithographic and printing techniques may be used to pattern subwavelength superstructures from NC assemblies across micro- to macroscales in order to construct hierarchical metamaterials and large-area optical devices.
3:00 pm – 3:30 pm BREAK
3:30 pm – 5:00 pm
Part IV: Jennifer Dionne
Plasmonic Approaches for Visualizing and Controlling Chemical Reactions
Molecular reactions mediated by metals are ubiquitous—spanning processes as diverse as photosynthesis, nitrogen fixation and oxygen transport in blood. Metal-mediated reactions also are foundational in devices ranging from batteries and fuel cells to nonvolatile memories. In each of these systems, chemical reactions typically occur near or within metallic clusters or nanoparticles. However, relatively little is known about how the nanoparticle structure—such as its shape, size and atomic arrangement—affects the thermodynamics and kinetics of such chemical reactions. To elucidate their function and enable next-generation technologies, it is crucial to observe chemical transformations in situ, as the reaction progresses, with nanometer- to atomic-scale spatial resolution. This tutorial will describe how plasmons in a variety of metallic nanostructures can be used to visualize and control chemical transformations with such resolution. We will focus on catalysis, photocatalysis and chiral sorting as applications. Participants of the tutorial will gain an improved understanding of (1) plasmonic excitation and decay in nano-sized metals; (2) nanoparticle synthesis; (3) sub-diffraction-limited microscopy techniques including TEM-CL/EELS (transmission electron microscopy-cathodoluminescence/electron energy-loss spectroscopy) and AFM (atomic force microscopy); and (4) how chemical and photochemical transformations unfold near nanoparticles.
- Andrea Alù, The University of Texas at Austin
- Dragomir Neshev, The Australian National University
- Cherie R. Kagan, University of Pennsylvania
- Jennifer Dionne, Stanford University