Tunable and reconfigurable metasurfaces and metadevices
Metasurfaces, two-dimensional equivalents of metamaterials, are engineered surfaces consisting of deep subwavelength features that have full control of the electromagnetic waves. Metasurfaces are not only being applied to the current devices throughout the electromagnetic spectrum from microwave to visible light but also inspiring many new thrilling applications such as programmable on-demand optics and photonics in future. In order to overcome the limits imposed by passive metasurfaces, extensive researches have been put on utilizing different materials and mechanisms to design active metasurfaces. The recent progress in tunable and reconfigurable metasurfaces and metadevices has been reviewed through the types of active materials employed. Various control mechanisms including electrical, thermal, optical, mechanical, and magnetic are also reviewed in each part. Finally, different materials and mechanisms have their pros and cons discussed and the perspective for their future development for applications is mentioned.
Materials and mechanisms in tunable metasurfaces (left) and art view of a tunable metasurface for holographic display (right)
The research group of Prof. Jinghua Teng from the Institute of Materials Research and Engineering, A*STAR, Singapore, proposed to do a review on tunable and reconfigurable metasurfaces and metadevices since there are huge interests in the community on this topic while there are also many choices of materials and mechanisms to produce tunable metasurfaces. It is the purpose of this paper to review the works published in this field to provide an easy reference and guide for scientists and scholars interested. The paper provides a comprehensive review of the literature about tunable and reconfigurable metasurfaces. The properties of most of the materials and the tuning mechanisms are discussed with those highly cited and featured examples of materials and tuning mechanisms being explained in details. The paper also gives the comparison of the different materials and mechanisms in terms of their operation spectrum, modulation speed, and tuning depth etc. Scientists and scholars who are working or interested in this field would benefit from reading this review article by getting a quick overview of works which have been done so far and the perspective of this field in near future in both research and application.
The Institute of Materials Research and Engineering (IMRE) is a research institute of the Agency for Science, Technology, and Research (A*STAR), Singapore. The Institute has a unique combination of R&D capabilities including state-of-the-art facilities, commercial partnerships, and strategic alliances. Comprehensive materials-related solutions for global and local partners are developed at IMRE. Prof. Jinghua Teng is leading a research group in IMRE working on optics and photonics to pursue both fundamental science study and cutting-edge technology development for industrial applications through innovations in design, materials, and fabrication. The group has extensive expertise and research in nano-optics-photonics, metamaterials and metasurfaces, plasmonics, semiconductor materials and devices, 2D materials and 2D optoelectronics, and Terahertz technologies. They also collaborate actively with scientists from both academic institutions and industry partners, globally and locally.
Nemati A, Wang Q, Hong M H, Teng J H. Tunable and reconfigurable metasurfaces and metadevices. Opto-Electronic Advances1, 180009 (2018).