Bridging surface plasmon polaritons and the digital world
Recently, Prof. Tie Jun Cui's group at Southeast University (SEU) has collaborated with Prof. Yu Luo at Nanyang Technological University (NTU), Singapore, and reported a breakthrough on this topic in National Science Review entitled "Active digital spoof plasmonics" (the first author is a graduate student, Hao Chi Zhang). In this work, a digital spoof surface plasmon polariton (SSPP) metamaterial is presented to achieve the combination of the tightly confined SSPP waves and the digital coding and modulation technologies.
Research on SSPPs has been a hotspot in the physical and microwave engineering communities since Prof. Tie Jun Cui's group proposed the first ultrathin corrugated metallic strip as the conformal SSPP waveguide in 2013. However, the existing SSPP metamaterials are not tunable after fabrication and cannot realize the real-time manipulations of SSPP waves in the subwavelenth scale.
To solve the problem, the SEU-NTU joint group proposed discrete and dynamic controls of the SSPP waves by judiciously designing the surface metallic patterns and state-change medium. Two discrete dispersion states of the active digital spoof plasmonics are constructed, corresponding to "0" and "1" states in the digital world. Based on the presented strategy, the joint group successfully designed a SSPP-based digital coding device which can implement both amplitude and phase modulations on a single SSPP platform. Hence, this work breaks the barrier between SSPPs and the digital world, and extends the scope of digital coding metamaterial in manipulating the confined electromagnetic waves, which opens a new avenue to novel system applications based on the digital coding metamaterials.
Hao Chi Zhang et al, Active digital spoof plasmonics, National Science Review (2019). DOI: 10.1093/nsr/nwz148
Provided by Science China Press