Zhuo Li

ABOUT

Mr. Zhuo Li is currently a Ph.D. candidate in the Nano Energy Lab, at the Department of Mechanical Engineering, Carnegie Mellon University (CMU). Before joining CMU, he received the bachelor's degree in Physics (2019) form University of Chinese Academy of Sciences, Beijing, China. He also received the Master's degree in Mechanical Engineering (2021) from CMU on the way of persuing the Ph.D. degree. Zhuo has a board research interest in the optical and photonic disciplines, including optical active particle/surfaces, metasurfaces, thermal plasmonics, and infrared emission/detection in the nanoscale. His research extensively involves a variety of numerical techniques, including the finite-difference time-domain (FDTD) method and finite element method (FEM).

NEWS

September, 2022

Optical responses of metasurfaces can be changed even after fabrication! Our work about graphene-coupled active metasurfaces is recently published in Physcial Review B. In this work, we proposed a feasible way to couple single-layer graphene to plasmonic metasurfaces and actively tune their optical responses via electrical gating. This work provide a second chance to re-engineer metasurfaces after fabrication if people want them to function in different ways.

RECENT PROJECTS

Bio-inspired Anti-reflection Structures

Leafhoppers (left) have their wings covered by a complex spherical stucture with polygon shaped through holes distirbuted among surfaces, known as brochosomes (left inset), for the proposes of reflection reduction and camouflage. Though people do not believe the God roll dices while desgining such a complex sctucture, the anti-reflection mechanism of brochosome stuctures remains unclear. With recent advance in the FDTD simulation and nano fabrication techniques, we are aiming at revealing the underlying physical mechanism of such a unique stucture to function as an anti-reflection coating.

Ultra-compact Metasurfaces

Metasurfaces are arrays of optical-active plasmonic structures (left). They alter the wavefront of light by introducing phase shift during the light-metasurface interactions. Previous simulation studies of metasurfaces focus more on infinite arrays by applying periodic boundary conditions. In our work, we instead, studied the finite-sized metasurfaces (middle) and found that they are able to achieve the majority of the desired performance compared to infinite ones, despite their tiny overall sizes. Specifically, we benchmarked the reflective spectra (right) of metasurfaces with different array sizes and managed to achieve the theoretical performance (black curve) by only a 7 by 7 array (purple curve). This work fills the gap between the previous theoretical works about ideal infinite metasurfaces and real applications, where ultra-compact footprints and fast response speeds are of equal importance as optical performances.

More to come! Please come back and check later.

Publications

1. J. Li, Zhuo Li (co-first author), X. Liu, S. Maslovski, S. Shen. Active control of thermal emission by graphene-nanowire coupled plasmonic metasurfaces. Physcial Review B, 106, 115416, 2022. [Read]
2. X. Liu, Zhuo Li (co-first author), Z. Wang, H. S. Yun, S. Shen. Design and analysis of electrothermal metasurfaces. ArXiv: arXiv:2206.13315 [physics.optics], 2022 (publish pending in Frontier in Energy). [Read]
3. Zhuo Li, J. Li, X. Liu, H. Salihoglu, S. Shen, Wiener chaos expansion method for thermal radiation from inhomogeneous structures, Physical Review B, 104 (19), 195426, 2021. [Read]
4. J. Li, J. Wuenschell, Zhuo Li, S. Bera, K. Liu, R. Tang, H. Du, P. R .Ohodnicki, S. Shen, Fiber Coupled Near‐Field Thermoplasmonic Emission from Gold Nanorods at 1100 K, Small, 17 (17), 2007274, 2021. [Read]
5. J. Li, Zhuo Li, and S. Shen, Degenerate quasi-normal mode theory for near-field radiation between plasmonic structures, Optics Express 28, 34123-34136, 2020. [Read]
6. Conference talk: 'Active Control of Thermal Emission by Graphene-Nanowire Coupled Plasmonic Metasurfaces' International Mechanical Engineering Congress & Exposition. Columbus, OH, Oct. 30 - Nov. 3, 2022.
7. Conference Talk: 'Thermal Radiation Spectra of Nanoplasmonic Structures: Simulation, Theory and Application' 21st symposium on thermophyscial properties. Boulder, CO, Jun 2021.

Educations