Abstract-Revealing the physical mechanisms behind large field enhancement in hybrid spoof plasmonic systems

Yao Huang, Jingjing Zhang, Tie Jun Cui, Zhen Liao, and Dao Hua Zhang

https://www.osapublishing.org/josab/abstract.cfm?uri=josab-35-2-396&origin=search

We compare different spoof localized surface plasmon (LSP) schemes for increasing the field enhancement in the subwavelength regime. Based on the mechanisms of three differently widely used corrugated metallic disk structures, we compare three widely used corrugated disks and propose a nonconcentric spiral-shaped metallic disk structure, which not only maximizes the electromagnetic field confinement but also effectively reduces the radiation loss. The performance can be further improved by adopting a hybrid system consisting of two closely spaced nonconcentric spiral structures. We show that such a dimer of nonconcentric spiral disk produces significant field enhancement compared with the previously discussed structures. Our study provides a perceptive guideline for potential applications, such as plasmonic sensors and antennas, associated with LSPs in the microwave and terahertz frequencies.

© 2018 Optical Society of America

Abstract-A combined system for efficient excitation and capture of LSP resonances and flexible control of SPP transmissions

Zhen Liao, Xiaopeng Shen, Bai Cao Pan, Jie Zhao, Yu Luo and Tie Jun Cui

ACS Photonics

DOI: 10.1021/acsphotonics.5b00096

http://pubs.acs.org/doi/abs/10.1021/acsphotonics.5b00096?journalCode=apchd5

We propose a compact combined system which supports compound spoof surface resonances due to the coupling between spoof surface plasmon polaritons (SPPs) and localized surface plasmons (LSPs). The system is composed of ultrathin metallic spiral structures for discrete LSP resonances and an ultrathin corrugated metallic strip to guide continuous SPP modes. We demonstrate both theoretically and experimentally that the LSP resonances can be efficiently excited and captured by the SPP waveguide, while the SPP transmissions can be judiciously controlled by the LSP structures. The spoof SPP-LSP combined system may find potential applications in sensing and integrated photonic circuitry in the microwave and terahertz frequencies.

Abstract-High-order localized spoof surface plasmon resonances and experimental verifications

• Zhen Liao,
• Yu Luo,
• Antonio I. Fernández-Domínguez,
• Xiaopeng Shen,
• Stefan A. Maier
• & Tie Jun Cui

http://www.nature.com/srep/2015/150410/srep09590/full/srep09590.html

We theoretically demonstrated and experimentally verified high-order radial spoof localized surface plasmon resonances supported by textured metal particles. Through an effective medium theory and exact numerical simulations, we show the emergence of these geometrically-originated electromagnetic modes at microwave frequencies. The occurrence of high-order radial spoof plasmon resonances is experimentally verified in ultrathin disks. Their spectral and near-field properties are characterized experimentally, showing an excellent agreement with theoretical predictions. Our findings shed light into the nature of spoof localized surface plasmons, and open the way to the design of broadband plasmonic devices able to operate at very different frequency regimes.