Title: Structured Light and Darkness in Nanophotonics
Abstract: When multiple light beams overlap in three-dimensional space, their interference produces lines of complete darkness – optical vortices that can form closed loops – links or knots. In this talk, we discuss how the synergy of structured light and darkness with nanostructured photonic media could bring new dimensions to the science and applications of light. Today, the term “structured light” describes a variety of optical waveforms with the spatial inhomogeneity of one or more physical parameters in two- or three-dimensional space and time. Topological concepts once considered mostly in the domain of abstract mathematics or theoretical physics, such as singularities of the phase or polarization, topological textures, and spin-orbit interactions nowadays are entering the field of classical and quantum optics. We design all-dielectric optical nanostructures enabling unprecedented control over the amplitude, phase, and polarization of optical fields, for the generation of optical beams with an orbital angular momentum (OAM), as well as optical links and knots, and study their stability in linear and nonlinear media. For example, by exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a single-mode OAM microring laser. Next, using the mathematical framework of supersymmetry, we design and demonstrate a stable two-dimensional microlaser array that is scalable and could prove to be a practical platform for developing complex nanophotonic systems. Finally, we discuss a new family of null solutions to the Helmholtz equation in three-dimensional free space - optical links and knots, their generation and robustness in the presence of atmospheric turbulence, and their interactions with nonlinear optical media.
About the Speaker: Natalia Litchinitser is a Professor of Electrical and Computer Engineering and a Professor of Physics at Duke University. Her research focuses on linear and nonlinear optics in engineered nanostructures, metamaterials, topological photonics, as well as the engineering of the light beams themselves. Natalia M. Litchinitser earned her Ph.D. degree in Electrical Engineering from the Illinois Institute of Technology and a Master’s degree in Physics from Moscow State University in Russia. She completed her postdoctoral training at the Institute of Optics, the University of Rochester in 2000. Natalia Litchinitser previously was a Professor of Electrical Engineering at the University at Buffalo, The State University of New York, a Member of Technical Staff at Bell Laboratories, Lucent Technologies, and a Senior Member of Technical Staff at Tyco Submarine Systems. She authored 7 invited book chapters and over 250 journal and conference research papers. She is a Fellow of the American Physical Society (APS), a Fellow of Optica (formerly the Optical Society of America), a Senior Member of the IEEE and SPIE, a co-Chair of CLEO Fundamental Science and SPIE Nanoscience and Engineering Applications conferences in 2021-2022.