Down-scaling optics to sub-wavelength dimension is one of the key challenges for developing optical nanocircuits and nanodevices. Plasmonics, the sub-wavelength surface electromagnetic waves that are guided on a metal-dielectric interface, enable a promising approach for achieving such down-scaling due to its extreme light confinement. However, current plasmonic devices encounter significant limitations due to high optical losses and the lack of efficient tunability and functionality. In this talk, the speaker will present two examples of plasmonic structures which can overcome these limits: (1) Gate tunable chip-based active plasmonic nanocircuits, and (2) Photonic crystal fiber-based hybrid plasmon waveguides.
The speaker will first present the use of gate-tunable low-loss active materials, transparent conducting oxides, to demonstrate an efficient on-chip nano-scale plasmonic modulation operating via field-effect dynamics. In addition, the speaker will present a plasmonic coherent resonant system used to engineer optical dispersion and to serve as an ultra-compact resonator, color router, and logical device. The speaker will then discuss the integration of plasmonics and “holey” fiber optics for the development of a new class of hybrid plasmonic/photonic waveguides. Such hybrid fibers provide a promising novel platform with controllable optical dispersion and long interaction length for the investigation of plasmonic optical properties and the realization of novel in-fiber devices. These studies open up new directions for enhancing nano-scale light-matter interactions and implementing future nanophotonic communication chips, controllable metamaterials, and hybrid optical fiber systems.
About the speaker
Dr Howard Lee is a Postdoctoral Fellow at the California Institute of Technology in Prof Harry Atwater's group in the Applied Physics Department. He received his PhD in Physics from the Max Planck Institute for the Science of Light in Germany in 2012 (Prof Philip Russell’s group) and BSc in Applied Physics from the City University of Hong Kong in 2007. His research focuses on developing new techniques in nanophotonics and plasmonics, including developing novel materials and nanostructuring to control the interaction between light and matter at the nanometer length-scale, and to study emergent optical phenomena of novel nanophotonic devices. Dr Lee is the recipient of the Croucher Postdoctoral Fellowship and his articles have been published in various journals, including Optics Letters, Optics Express, Applied Physics Letters, Advanced Materials, Nano Letters and Science.
The seminar is free and open to all. Seating is on a first-come, first-served basis.
