In this talk, I will present some of our work in the fascinating field of plasmonics. First, we demonstrate that plasmonic nanostructures can significantly modify the photonic density of states, and enhance the spontaneous emission. Such a strong Purcell effect can suppress photo bleaching, a photochemical reaction that permanently damages fluorescent molecules. As a result, a single molecule can emit up to 1,000 times more photons before bleaching. Second, I will present a fully subwavelength and efficient nano-plasmonic source for unidirectional generation of surface plasmons, which is a key building block for the next generation of ultra-fast and ultra-compact integrated optical circuits. By tailoring the relative phase at resonance and the separation between two magnetic metamaterial resonators, surface plasmons can be steered to predominantly propagate along one specific direction. Finally, I will introduce a new concept of transformation plasmonics to mold near-field plasmon waves at the metal-dielectric interface in a prescribed manner. For instance, this approach enables surface plasmon waves to travel smoothly at uneven surfaces, where surface plasmons would normally suffer considerable scattering losses. Some plasmonic devices, such as a plasmonic Luneburg lens and reconfigurable plasmofluidic lenses, will also be presented.
报告人简介： Dr. Yongmin Liu received his B.S. and M.S. degrees in Physics at Nanjing University (Nanjing, China) in 2000 and 2003, respectively. After obtaining his Ph.D. from the University of California, Berkeley in 2009, he stayed at UC Berkeley as a postdoctoral fellow for three years. In fall 2012, he joined the faculty of Northeastern University at Boston, with a joint appointment in the Department of Mechanical & Industrial Engineering and the Department of Electrical & Computer Engineering. He has authored and co-authored 40 journal papers including Science, Nature, Nature Nanotechnology, Nature Communications, Physical Review Letters and Nano Letters. He currently serves as an editorial board member for Scientific Reports and EPJ Applied Metamaterials.
