Lan Yang
Edwin H. and Florence G. Skinner professor
Preston M. Green Department of Electrical and Systems Engineering
Washington University in St. Louis
Seminar: Opportunities in Optical Microresonators: Fundamentals and Applications
Abstract: Light-matter interactions are the fundamental basis for many phenomena and processes in optical devices. I will talk about ultra-high-quality whispering-gallery-mode (WGM) optical microresonators, which provide unprecedented capability to trap light in a highly confined volume smaller than a strand of human hair. Light beams can travel around the boundary of a WGM resonator over 10^6 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.
In this talk, I will report some recent research discoveries from my group in this exciting field. I will present a few cases demonstrating the great potential of high-Q WGM microresonators and microlasers for both fundamental science and engineering applications. Specifically, I will discuss ultra-high-Q microresonators and microlasers for ultra-sensitive detection and characterization of nano/microscale objects. Afterwards, I will discuss our recent exploration of fundamental physics, such as parity-time 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 systems 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.
About the Speaker: 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 in St. Louis. She is also the editor-in-chief of Photonics Research. She earned her B.S. from the University of Science and Technology of China and her PhD. in applied physics from Caltech in 2005. Her research interests have been focused 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 earned an NSF CAREER Award in 2010 for her work on single nanoparticle detection and sizing using an on-chip optical resonator. She is also the recipient of the 2010 Presidential Early Career Award for Scientists and Engineers (PECASE). She is a Fellow of the Optical Society of America, Institute of Electrical and Electronics Engineers, American Physical Society and American Association for the Advancement of Science.
Host: Xu Yi, assistant professor of electrical and computer engineering with a courtesy appointment in physics.