Anomalous reflection in the ultra-thin nano-strip antenna induced by incident field and displacement current phase matching

作者：Hu DeJiao^*; Wang Ping; Zhang Zhiyou; Pang Lin; Kim Sungwoon; Du Jinglei

来源：Journal of the Optical Society of America B-Optical Physics, 2015, 32(7): 1369-1376.

DOI：10.1364/JOSAB.32.001369

• Anomalous reflection
• Anomalous scattering
• Displacement currents
• Enhanced reflections
• Incident fields
• Reflection and transmission
• Reflection spectra
• Theoretic model

Recently, ultra-thin nano-strip antenna (thinner than skin depth) has attracted extensive attention as a key structure unit of metasurface. It can be used to realize anomalous enhanced reflection and absorption, as well as suppressed transmission, which has been used in photonic devices. However, there is still a lack of clear analysis to explain systematically these phenomena. In this paper, we present the concept of phase matching between the displacement current and the incident field, which initially leads to the anomalous scattering property of a single ultra-thin nano-strip antenna. Base on the property of a single nano-strip, we study the coupling of multi-nanostrip antennas and demonstrate that the randomized and periodic array of nano-strips have the same anomalous reflection spectrum. The phase matching is also reflected in the theoretic model, from which the reflection and transmission formulas for nano-strip array are derived. The formulas successfully predict the thickness influence on the reflection spectra of a periodic array. Our results can promote the development of ultra-thin nano-strip based metasurfaces.

• 出版日期2015-7-1
• 单位四川大学