Topological states of light and darkness: static, dynamic, and spatiotemporal vortices.

Seminar Link: Picoelectrodynamics Theory Network - YouTube


Broken symmetries are ubiquitous in physics and are associated with ferromagnetism, nonreciprocal effects, optical activity, molecular chirality, and vortex beams of photons and electrons. In some cases, symmetry breaking also leads to the formation of various topological states, excitations, or defects of a continuous field. In this talk, I will introduce the topology of light – the light carrying orbital angular momentum (OAM). The OAM of light can be static, dynamic, or spatiotemporal. Static OAM of light has been known for three decades and has found numerous applications, from optical trapping, super-resolution imaging, to tele- and quantum communications. On the contrary, time-varying and spatiotemporal OAM of light are new properties discovered over the past few years. I will talk about how we create and characterize time-varying and spatiotemporal OAM of light [1-4] and their potential future applications. 

By Prof. Chen-Ting Liao

Dr. Chen-Ting Liao is a research scientist at JILA, a joint research institute at the University of Colorado Boulder and NIST. He also serves as Assistant Director of Research and Knowledge Transfer of STROBE, the NSF Science and Technology Center on Real-Tim Functional Imaging. Originally from Taiwan, Dr. Liao received his B.S. degree in space science and MSc in physics. After working in the semiconductor industry for two years, he came to the US to study optics. He received his PhD in optical sciences from the University of Arizona in 2017. Dr. Liao then became a postdoc in JILA, working on ultrafast lasers, x-rays, and their applications to probe materials. He is the Finalist of two PhD thesis awards, including the 2018 WAGS-ProQuest Innovation in Technology Award and the 2019 American Physical Society (APS) Carl E. Anderson Division of Laser Science Dissertation Award. Also, he is selected as the 2022-2023 APS Career Mentoring Fellow. Recently, he won the 2023 Air Force Young Investigator Award (AFOSR YIP).