讲座题目：Exploring plasmonic hot spots and their dynamics in the near field by photoemission electron microscopy
主讲人：Dr. Quan Sun
主持人：吴伯涛
讲座时间：2016.12.21上午10:00
讲座地点：理科大楼A814室
报告人简介：
工作经历
16.4- 日本北海道大学，助理教授
17.1- 吉林大学，吉林省长白山讲座教授
11.4-16.3 日本北海道大学，特任助理教授
09.1-11.3 日本北海道大学，博士后（合作教授：Hiroaki Misawa）
06.3-08.12 加拿大拉瓦尔大学，博士后（合作教授：See Leang Chin and Réal Vallée）
学习经历
00.9-06.1 北京大学物理学院现代光学研究所，理学博士
(论文指导教师：龚旗煌院士、蒋红兵教授)
96.9-00.7 北京大学物理系，理学学士 (论文指导教师: 张国义教授)
报告摘要
Metallicnanoparticles can enable the localization of electromagneticfields on nanometer length scalesresulted from localized surface plasmon resonances (LSPRs). The areas with greatly enhanced electromagnetic field are often referred to plasmonic hot spots. Spatially and temporally resolving plasmonic hot spots become very crucial but still remains experimentally challenging. We report experimental studies toward this aim using photoemission electron microscopy (PEEM) with high spatial resolution of sub-10 nm. Various engineered gold nanostructure arrays are investigated via PEEM using near-infrared femtosecond laser pulses as the excitation source. We have explored the hot spots of both dipole and high order LSPRs. Not only bright (superradiant) but also dark (subradiant) LSPR modes can be identified. More importantly, the dynamics (dephasing) of the LSPRs are studied by time-resolved PEEM. In particular, we experimentally prove that the subradiant quadrupole mode have longer dephasing time than the superradiant dipole mode. Furthermore, we spatially and spectrally resolved hybridized plasmon modes in coupled plasmonic systems from the near field and discuss the crossover between plasmonic Fano resonance and plasmon hybridization.