Abstract
Studies of plasmonics focus on the nanoscale light-matter interaction in metal nanostructure-based cavities and their diverse applications in optoelectronics, biochemistry and energy harvesting [1]. Recent remarkable developments in this field have expanded to quantum plasmonics [2], topological graphene plasmons [3], nonlinear plasmonics [4], parity-time-symmetric plasmonic metamaterials and metasurfaces [5], and exciton-cavity strong coupling [6]. In this talk, I will present our research on the nanoscale optical properties of two strongly-coupled plasmonic nanocavities, particle-on-film golden junctions and core-molecule-shell metallic nano-resonators. Specifically, I will discuss plasmon mode hybridization and decomposition in the former cavity and its fascinating nano-optics effects such as plasmon-tailored photoluminescence [7-8], symmetry-breaking enhanced nonlinear optics and cavity-mediated plasmon-exciton coupling in two-dimensional materials (unpublished results). Following this, I will present the emergence of quantum features in the latter cavity, including electron-tunneling-altered far- and near-field optical behaviours and its implications in leveraging optical harmonic generation. Finally, I will briefly discuss future prospects of plasmonics and nanophotonics in biochemical sensing, super-resolution imaging and light-triggered energy conversion.
[1] S.A. Maier, Plasmonics: Fundamentals and Applications, Springer: New York (2007).
[2] M.S. Tame et al, Nat. Phys. 9, 329-340 (2013); S.I. Bozhevolnyi & J.B. Khurgin, Nat. Photon. 11, 398-400 (2017).
[3] D. F. Jin et al, Phys. Rev. Lett. 118, 245301 (2017); G. Siroki et al., Nat. Commun. 7, 12375 (2016).
[4] J. Lee et al., Nature 511, 65-69 (2014); M. P. Nielsen et al., Science 358, 1179-1181 (2017).
[5] Y. Sun et al., Phys. Rev. Lett. 112, 143903 (2014); H. Alaeian & J.A. Dionne, Phys. Rev. A 89, 033829 (2014).
[6] R. Chikkaraddy et al., Nature 535, 127-130 (2016); H. Memmi et al., Phys. Rev. Lett.118, 126802 (2017).
[7] D.Y. Lei et al, ACS Nano 6, 1380-1386 (2012); G.-C. Li, Y.-L. Zhang & D.Y. Lei, Nanoscale 8, 7119-7126 (2016).
[8] G.-C. Li et al., ACS Nano 11, 3067-3080 (2017); Q. Zhang et al., J. Opt. 20, 024010 (2018).
Biography
Dangyuan Lei received his BSc, MPhil and PhD degrees all in Physics from Northwest University, The Chinese University of Hong Kong and Imperial College London in 2005, 2007 and 2011, respectively. He has been an assistant professor with the Department of Applied Physics at The Hong Kong Polytechnic University since September 2012. His main research activities include nanophotonics and nanomaterials studies, with particular interest in plasmon-enhanced light-matter interaction at the nanoscale and their applications in energy harvesting, optoelectronic devices, and biophotonics. Since 2007, he has published 88 journal publications, including 28 articles in Nature Communications, Light: Science & Applications, Physical Review Letters, Advanced Materials, Nano Letters and ACS Nano etc., receiving 2650 citations and an H-index of 30 (by Google Scholar as of March 2018). Two publications have been respectively selected in the RSC “Emerging Investigators” themed issue of Journal of Materials Chemistry C (2016) and the IOP “Emerging Leaders” edition of Journal of Optics (2017). He has received several prestigious awards, including the “Deputy Rector’s Award” (2008-2011) and the “Anne Thorne PhD Thesis Prize” (2012) both from Imperial College London, the “Early Career Grants Award” from Hong Kong Research Grants Council (2013), a Royal Society International Exchange award (2016), and a Key Technology Partner Visiting Fellow of University of Technology Sydney (2017).
Anyone interested is welcome to attend.