Colloquium: Dr. Chia-Wei Hsu, Ph.D., Yale University, New Frontiers of Electromagnetic Phenomena at the Nanoscale
All dates for this event occur in the past.
Dreese 260
Abstract
Optics and photonics today enjoy unprecedented freedom. The ability to synthesize arbitrary light fields (through wavefront shaping) and the ability to design structures at the subwavelength scale (through nanofabrication) enable us to realize exciting new phenomena that were not accessible in the past. In this talk, I will present several such experiments and related theory. A) It is commonly thought that waves cannot be perfectly confined within the continuum spectrum of an open system. I will describe the first realization of “bound states in the continuum” that defy such conventional textbook wisdom as well as their underlying topological nature. This new way to confine light enables novel lasers, filters, and sensors . B) I will show that by tailoring the radiation of optical modes, we can realize non-Hermitian photonic band structures with no counterpart in closed Hermitian systems, such as rings of exceptional points and pairs of exceptional points connected by bulk Fermi arcs. C) By designing light fields, we can control wave transport even through unknown disordered structures. I will show that the multiple scattering of light leads to correlations between far-away photons and that using such correlations, we can simultaneously control orders of magnitudes more degrees of freedom than what was previously thought to be possible. I will conclude with my visions for new opportunities enabled by designed light fields and optical structures, including new paradigms for imaging and optical computing that have the potential to go beyond the current state of the art by orders of magnitude.
Bio
Dr. Chia-Wei Hsu is a postdoctoral researcher in Applied Physics at Yale University. He received his PhD in physics from Harvard in 2015 and BS in physics with high honors from Wesleyan in 2010. His research centers around controlling light in nanoscale structures and complex systems, through a combination of experiment and theory. He is the co-author of 32 peer-reviewed journal articles and the co-inventor of 3 patents, and has delivered over a dozen invited talks internationally. He won the LeRoy Apker Award given by the American Physical Society and was a finalist for the Blavatnik Regional Award for Young Scientists.