学术报告1：Ultra-high-Q microcavity optics and photonics

Yun-Feng Xiao

School of Physics, Peking University, P. R. China

Phone: +86-10-62765512, Fax: +86-10-62766567

e-mail: yfxiao@pku.edu.cn　; URL: www.phy.pku.edu.cn/~yfxiao/　

时间：2019.4.25 上午9：30

地点：瞬态室会议室

　　Confinement and manipulation of photons using microcavities have triggered intense research interest in both fundamental and applied photonics for more than two decades. Prominent examples are ultrahigh-Q whispering gallery microcavities which confine photons by means of continuous total internal reflection along a curved and smooth surface. The long photon lifetime, strong field confinement, and in-plane emission characteristics make them promising candidates for enhancing light-matter interactions on a chip. In the first part of this talk, I will introduce some representative photonics applications of ultrahigh-Q microcavities. In the second part, I will focus on (1) chaos-assisted momentum transformation in an asymmetrical microcavity, (2) spontaneous symmetry breaking of optical fields in a single ultrahigh-Q microcavity, and (3) second-order nonlinear optics induced by symmetry breaking at the surface of a silica microcavity under a sub-milliwatt continuous-wave pump.  

　　Dr. Yun-Feng Xiao received the B.S. and Ph.D. degrees in physics from University of Science and Technology of China in 2002 and 2007, respectively. After a postdoctoral research at Washington University in St. Louis, he joined the faculty of Peking University in 2009, and was promoted a tenured professor in 2014 a full professor in 2019. His research interests lie in the fields of whispering-gallery microcavity optics and photonics. He has authored or co-authored more than 150 refereed journal papers in Science, Nature Photonics, PNAS, PRL, Advanced Materials et al. He has delivered over 100 plenary/keynote/invited talks/seminars in international/national conferences/universities. 

学术报告2：微腔光梳的研究进展

Chun-Hua Dong
CAS Key Lab of Quantum Information, University of Science and Technology of China, Hefei 230026, China
e-mail: chunhua@ustc.edu.cn　;
URL: http://dsxt.ustc.edu.cn/zj_js.asp?zzid=3907　

　　This talk will present the frequency comb in the high-Q whispering gallery modes microresonator. The coherent temporal soliton in optical microresonators has attracted great attention recently. Here, we demonstrate the dissipative Kerr soliton generation in a microresonator, by utilizing an auxiliary-laser assisted thermal response control. By external tuning, the repetition rate of the soliton has been controlled over a large range of 30MHz. Our platform promises precise tuning and locking of the repetition frequency of coherent mode-locked comb in the microresonator, and holds great potential for applications in spectroscopy, quantum key distribution and precision measurements.

　　董春华，2002-2006年就读于中国科学技术大学物理系获理学学士，2006-2011年就读于中国科学技术大学物理系获理学博士学位，博士期间在美国圣路易斯大学进行交流访问半年。博士毕业后，2011年7月至2013年6月在美国俄勒冈大学进行博士后研究，2013年入选中国科学技术大学的引进人才，回到中国科学技术大学负责微腔光学和腔机械振子方面的研究工作。目前为中国科学技术大学量子信息重点实验室研究员。长期从事基于回音壁模式介质微腔的量子信息处理器的研究；在腔光力学、高品质因子微腔、微纳光学器件上多次取得重要突破。代表性工作有：在国际上首次利用双光学模式与腔机械振子的相互耦合，实现了光机械暗态，完成了任意波长光子的相互转换；实验上提出在介质微腔表面覆盖聚合物薄膜，实现了对微腔的有效调制，提高光与物质的相互作用；首次利用光纤锥波导实现了与银纳米线的有效耦合，为建立基于表面等离子体的光学元件提供有效可行的方法。曾在Science(1篇)、Nature Photonics1(1篇)，Nature Communications(2篇)、Optica(1篇)、Physical Review Letters(2篇)、Applied Physical Letters (5篇)、Optics Letters (4篇)等国际学术期刊发表论文60多篇，被SCI引用2000余次。