报告题目：Whispering-gallery-mode microresonators: fundamentals and applications

报 告 人：Lan Yang Professor，Washington University

时    间：2019年6月7日（周五）下午15: 00

地    点：南楼二层会议室

邀 请 人：刘新风 研究员

报告摘要：

Light-matter interactions are the fundamental basis for many phenomena and processes in optical devices. Whispering-Gallery-Mode (WGM) optical resonators trap light in a manner similar to a phenomenon found in the gallery spaces of St. Paul’s Cathedral dome in London, where a single whisper (i.e., a sound wave) can be heard along the circular boundary of the architecture. Ultra-high-quality WGM optical micro-resonators provide unprecedented capability to trap light in a highly confined volume smaller than a strand of human hair; a light beam can travel around the boundary of a WGM resonator over 106 times, significantly enhancing light-matter interactions, creating the potential for a wealth of new scientific discoveries and technological breakthroughs difficult to achieve by other devices. They have shown a great promise for a variety of fields of science, spanning from optomechanics to communication, non-Hermitian physics, sensing and metrology. In this talk, I will report the recent research discoveries from my group in this exciting field. I will present a few cases demonstrating the great potentials of high-Q WGM microresonators and microlasers for both fundamental science and engineering applications. I will start with the discussion of ultra-high-Q microresonators and microlasers for ultra-sensitive detection of nanoscale objects. Afterwards, I will discuss our recent exploration of fundamental physics, such as parity-time symmetry (PT-symmetry) and light-matter interactions around exceptional points (EPs) in high-quality WGM resonators, which can be used to achieve a new generation of optical system enabling unconventional control of light flow. Examples including nonreciprocal light transmission, loss engineering in a lasing system, directional lasing emission, and EPs enhanced sensing, will be introduced. A non-Hermtian phonon laser tuned in the vicinity of EPs will be discussed briefly. In the end I will present a new generic and hand-held microresonator platform transformed from a table-top setup, which will help release the power of high-Q WGM resonator technologies. I will wrap up my talk with an overview of Photonics Research, a journal to promote and disseminate high-quality research in photonics and optics.

报告人简介：

Professor Lan Yang is the Edwin H. and Florence G. Skinner professor in the Preston M. Green Department of Electrical and Systems Engineering at Washington University, St. Louis, MO, USA. She received B.S. from the University of Science and Technology of China and received her Ph.D. in applied physics from Caltech in 2005. Her research interests have been focusing on the fundamental understanding of high-quality photonic whispering-gallery-mode (WGM) resonators and their applications for sensing, lasing, light harvesting, and communications. Recently, her research interests expanded to parity-time-symmetry and non-Hermitian physics in high-quality WGM resonators, which have led to a series of new discoveries for unconventional control of light transport in photonic structures. She is the recipient of the 2010 Presidential Early Career Award for Scientists and Engineers (PECASE) for her work on chip-scale microlasers and her pioneering studies of nanoparticle detection using high-quality optical resonators. She has published ~100 papers in peer-reviewed journals, including Science, Nature, Nature Photonics, Nature Nanotechnology, Nature Physics, and PNAS, etc. She is a fellow of the Optical Society of America (OSA). Currently, she serves as the editor-in-chief for Photonics Research.