IQSE AMO/QO Seminar Series

"Whispering-gallery-mode microresonators and their applications"

Lan Yang
Washington University, St. Louis


Light-matter interactions are the fundamental basis for many phenomena and processes in optical devices. Ultra-high-quality whispering-gallery-mode (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, which significantly enhances light-matter interactions, leading to a wealth of new scientific discoveries and technological breakthroughs difficult to achieve by other devices. In this talk, after briefly introducing the physical concepts of WGM microresonators and providing an overview of the research discoveries in the past twenty years, I will report the recent progress in my group towards developing functional platforms using high-Q WGM microresonators and microlasers. Specifically, I will discuss ultra-high-Q microresonators and microlasers for ultra-sensitive detection of nanoscale objects. I will explain a self-referencing sensing scheme for detection and sizing of single virion, dielectric and metallic nanoparticles. These advancements in WGM microresonators will enable a new class of ultra-sensitive and low-power sensors for investigating the properties and kinetic behaviors of nanomaterials, nanostructures, and nanoscale phenomena. 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 systems enabling unconventional control of light flow. Examples including nonreciprocal light transmission, loss induced revival of lasing, chiral modes for directional lasing emission, and EPs enhanced sensing, will be introduced. In the end, I will present a new generic and hand-held microresonator platform that was transformed from a table-top setup, which might help release the power of high-Q WGM resonator technologies.

Monday, November 13, 2017
IQSE Seminar Room, 12:00 Noon
(578 MPHY)

Institute for Quantum Science and Engineering
Texas A&M University

Lunch (sandwich) will be served 15 minutes prior to start time