Invited talk by Zhengli Han

Title for the talk: MEMS and Metasurfaces for Sustainable Dynamic Photonics

Oplysninger om arrangementet

Tidspunkt

Mandag 27. marts 2023,  kl. 13:00 - 14:00

Sted

Helsingforsgade 10, 5123-314

Abstract: Optical metasurfaces are engineered two-dimensional structure arrays with sub-wavelength periodicity. They allow for complete control of phase, amplitude, polarization and angular momentum of transmitted/reflected optical waves based on the design of the metasurfaces. They have been intensely studied in the past decades due to their practical applications for making smaller, thinner, and cheaper mass-produced optical components, such as filter, lenses, etc. Active metasurfaces are also starting to be reported. Among active control methods, MEMS (micro-electro-mechanical system) approach is very promising as it reconfigures the metasurface structures directly, enabling dramatic changes of optical properties, which are difficult to achieve for other control methods. This talk will present two examples of how MEMS technique is combined with optical metasurfaces for: 1) a novel optical display that involves few materials and is easier to recycle at the end of its usage [1], and 2) a novel THz modulator which among the first active THz devices [2]. Besides, thin film multilayer metasurfaces with a spectral phase singularity will also be shown, which has potential applications in sensing and modulation [3]. Finally, based on the above, platforms with MEMS and metasurfaces for future sustainable dynamic photonics will be introduced (research proposal).
[1] Z. Han, C. Frydendahl, N. Mazurski, and U. Levy, “MEMS cantilever-controlled plasmonic colors for sustainable optical displays,” Science Advances 8(16), eabn0889, 2022.
[2] Z. Han, K. Kohno, H. Fujita, K. Hirakawa, and H. Toshiyoshi, “MEMS reconfigurable metamaterial for terahertz switchable filter and modulator,” Optics Express 22 (18), 21326-21339, 2014.
[3] Z. Han, S. Ohno, and H. Minamide, “Spectral phase singularity in a transmission-type double-layer metamaterial,” Optica 7 (12), 1721-1728, 2020.

Bio: Zhengli Han is currently a postdoc at the Mads Clausen Institute in the Center of Nano Optics at the University of Southern Denmark (SDU). She completed her PhD in MEMS reconfigurable THz metasurfaces at the University of Tokyo in 2014. She then joined RIKEN Center for Advanced Photonics as a postdoc, where she continued to work on THz metasurfaces for THz phase control devices. During her time in Riken, she was awarded the RIKEN SPDR fellowship. In 2019, she moved to the Hebrew University of Jerusalem, where she worked on MEMS and plasmonic metasurfaces for novel sustainable optical displays. In 2022, she moved to Denmark and worked at the Technical University of Denmark (DTU) for a short-time postdoc. In 2023, she joined SDU as a postdoc. She was recently awarded the MSCA fellowship (2023-2025). She is interested with MEMS and metasurfaces for dynamic photonic applications.