Optical Metamaterials and Metasurfaces: Design, Fabrication, and Applications
Date: October 16, 2026; Time: 2:30 PM Location: PWEB 175
Abstract: Optical metamaterials are artificially engineered structures whose properties are primarily governed by their geometry rather than their chemical composition. By designing subwavelength building blocks—called meta-atoms—and engineering their spatial arrangement, we can realize exotic optical properties that are difficult or impossible to achieve with natural materials. Metasurfaces, the two-dimensional counterparts of metamaterials, can manipulate light on an ultrathin platform. This capability opens the door to extremely compact optical components, which could potentially replace conventional bulky lenses, waveplates, and holographic elements.
In this talk, I will begin by introducing the fundamentals of optical metamaterials [1] and metasurfaces [2], including the underlying physical mechanisms, the key principles that guide their design, and the state of the art in nanofabrication. In particular, machine learning and deep learning have emerged as powerful tools to significantly accelerate the design of sophisticated metamaterials and metasurfaces, overcoming the limitations of conventional numerical or optimization methods [3]. I will then focus on our recent work on metasurface-based applications, including high-capacity holograms [4, 5] and nanoprinting images [6], demonstrating how a single ultrathin device can encode and display rich optical information through multiple channels such as wavelength and polarization.
References: [1] Y. M. Liu and X. Zhang, Chemical Society Review 40, 2494 (2011). [2] N. Yu and F. Capasso, Nature Materials 13, 139 (2014). [3] W. Ma et al., Nature Photonics 15, 77 (2021). [4] B. Xiong et al., Science 379, 294 (2023). [5] W. Ma et al. Advanced Materials 34, 2110022 (2022). [6] L. Deng et al., Advanced Functional Materials 36, e16059 (2026).
Biographical Sketch: Dr. Yongmin Liu obtained his Ph.D. from the University of California, Berkeley in 2009. He joined the faculty of Northeastern University in Boston in Fall 2012, and currently he is currently a full professor with a joint appointment in the Department of Mechanical & Industrial Engineering and the Department of Electrical & Computer Engineering. Dr. Liu’s research interests include nano optics, nanoscale materials and engineering, plasmonics, metamaterials, biophotonics, and artificial intelligence. He has authored and co-authored more than 150 journal papers, including Science, Nature, Nature Photonics, Nature Nanotechnology, Advanced Materials, Physical Review Letters, and Nano Letters. Dr. Liu was a recipient of the Søren Buus Outstanding Research Award at Northeastern University (2024), the Faculty Fellow of College of Engineering at Northeastern University (2019), NSF CAREER Award (2017), Office of Naval Research Young Investigator Award (2016), SPIE DCS Rising Researcher Award (2016), and 3M Non-Tenured Faculty Award (2016). He has served as an associate editor or editorial board member for Nano Convergence, Nanophotonics, PhotoniX, IEEE Journal of Selected Topics in Quantum Electronics, and EPJ Applied Metamaterials. He is a Fellow of both OPTICA (formerly OSA) and SPIE.